Genetics, Evolutionary Biology, and Evolutionary Variation

Introduction (and Semi-Disclaimer)

I'm calling this an article about genetics. It is such. But -- fair warning --it is also, and most especially, an article about evolution, because genetics andevolution are inextricably linked. Obviously this is controversial among non-scientists(although hardly among scientists, because the evidence is overwhelming), but I have todo my best to cover all aspects of textual criticism. And, if you study evolution,and then read this article, you will surely see why I decided I had to write this.

Much of this has been very difficult to write; I've already produced at leasthalf a dozen differentversions just of this disclaimer, doubtless spending vastly more time than it's worth.I've tried to figure out a way to finesse this -- toargue that the question of whether evolution is "real" is not very important-- but I don't think the argument can besustained. You can be a good textual critic whether you believe in evolution or not --but, after some months of study of the recent changes in the understandingof the theory of evolution, I am completely convinced that you will be a better oneif you can learn from what we know about evolution.This apart from the fact that a correct understanding of evolution is vital in politics,because the implications of evolution require certain policies which politicians and the generalpopulation are often unwilling to admit. (There is nothing unique about that. Thesame goes at least double for thermodynamics. There are times when I think that thebest way to succeed in American politics is to go into therapy to have all knowledgeof science erased from one's brain.)

So let it be stated: I believe in evolution. I believe it because all life on earthshares the same genetic code -- that is, all species use the same DNA encoding foramino acids, meaning that a gene from, say, corn, can be inserted into, say, an apeand still produce the same protein. This means that bacteria and viruses can (and do)share genes, meaning that evolution, even if it didn't happen in the past, willhappen in the future. I believe in evolution because it'shappening right now. Indeed, it can be made to happen in the lab. I believein it because it explains so much that is bad about human behavior -- wars, murders,crime, false advertising. Indeed, onerecent theory has it that the reason humans developed large brains is for purposesof manipulating and tricking each other. There are only two species in which malesband together to make war on their neighbours. They are human beings -- and, it turnsout, chimpanzees, our closest relatives. (And we thought they were our closestrelatives even before this behavior was discovered.) I don't much like evolution,given how it seems to be working out. Much as I'd like to deny it, I can't see away to avoid it.

An alternate point: Suppose the Biblical account of creation is literally true. This meansthat all human beings are descended from Ham, Japeth, and Shem, who had their first childrensome 4500 years ago. (Which, curiously, is after the earliest historical records fromEgypt and Mesopotamia.) In that time, the children of the three brothers would have todifferentiate into Inuit (dark skin, short, squat, designed to be well-insulated), NorthernEuropeans (blonde or red-haired, with light skin to capture vitamin D), Africans (dark,often very slender), and other types. If that isn't evolution, what is?

Let me offer an analogy as to why I think it matters even if perhapsit isn't "true." If evolution did not create biodiversity, then the Creator createdit to look as if evolution created biodiversity, by supplying fossils and such.This is like looking at a clock which reads, say, 7:00 a.m. You can't tellby looking at the clock if it started months ago and has been running ever since,or if someone five minutes ago set it to read 6:55 and started it running. You getthe same result either way. The universe is like that clock: It may be 13 billionyears old, or it may be that it is a clock created a few thousand years ago toread "13 billion years." (For all we can prove, in that sense,it could be a clock created a second ago, and all our memories before that timewere created with it.) Either way, the universal clock reads 13 billion years.

I'll leave out the further impassioned appeals. They won't change anyone's minds;there is now evidence that certain religious beliefs and thought patterns are hardwiredinto our minds, so what is logical and true for one is not logical to others.Perhaps our greatest need is to be understanding; if you don'tbelieve in evolution, I can only ask that you keep an open mind about what follows,because others are made differently.

For those who want such a thing, I have given an argument (see thenote) for why evolution andthe Big Bang do not contradict the Biblical account -- but I doubt this helps much.I could repeat that much of what follows is less evolution than simple genetics,which for some reason is non-controversial. But evolution is inherent in genetics: Ifyou have genes, and if you have some genes surviving and some not, you will getevolution. If you want to skip the evolution material, you can derive some benefitfrom skipping to the appendix on genetics.

Also, evolution isn't just about bacteria developing antibioticresistance or Homo Erectus turning into Homo Sapiens. It'sabout anything with a gene analogy being placed under pressure tosurvive. This has led to a concept known as "universalDarwinism." That is, the belief that natural selection applies tomore than just living things. Where there is competitivepressure, meaning that only some members of a population can survive,the larger share of those that survive will be the ones which best meet theselection criteria. It's statistical, and it depends on conditions, and ittakes time (quite a lot of time if the selective pressure is slight, whichit usually is) -- but it is sure to apply as long as there is some sort ofselection. A possible example of this is the meme. Similarly,all else being equal, well-written books will sell better than poorly-writtenbooks, so as time passes, libraries tend to contain more and more readablebooks. Good television shows get renewed; bad ones get cancelled. Politicianswho are willing to do and say anything beat those who take stands and causeportions of the population to disagree with them. You could argue that the canonof the Bible, or of other religious books, is an example: If scribes and parchmentwere infinite, many more books might have been retained in the canon. But sinceonly so many copies could be made, a canon had to be fixed so scribes would notwaste their time on relatively unimportant works. And with the canon fixed, thoseother documents -- the Letter of Barnabas, the Didache, etc. -- effectively diedout. The rulesof natural selection vary (the primary attribute of a successful televisionshow seems to be stupidity, which obviously is not a very useful trait innature). But natural selection has to take place.

We might add that evolution as understood today is not really the same aswhat most of us encountered in school. Part of this, at least in American schools,is the ongoing dumbing-down of the science curriculum for political reasons. Butevolutionary theory itself is changing; except for theconcept of Natural Selection, what remains is distinctly different from Darwin.(Or, in one case, it is very much like Darwin, but unlike his successors. Darwinproposed that selection was driven by two types of selection: Natural Selection andSexual Selection. Natural Selection was, so to speak, a hit: Biologists understoodit easily and adopted it at once. But sexual selection, which explains such thingsas the peacock's tail and the bowerbird's bower and the bright coloration of parrots,was almost completely ignored for a century after Darwin -- even though there is nowoverwhelming evidence that it affected, for instance, the development of humans.)The latest great change was brought about by none other than that infamouszealot Richard Dawkins. For many years after Darwin, people thought of evolutionin terms of organisms and species. Even after genes were discovered, they were just the mechanismof evolution -- even though genes, once understood, solved a problem thatDarwin had never solved: how survival adaptions managed to avoid being dilutedby all the un-adapted creatures. (In Darwin's day, heredity was thought to be asort of an analog process: Children were mixures of their parents' traits. Withgenes, suddenly, instead of children getting half of a longer beak, they eitherhad a long-beak gene or a short-beak gene. No half-way measures any more.)

Dawkins further modified this by bringing forward the notion of the "SelfishGene." The survival imperative applies to genes, not wholeorganisms. Mostly it is expressed in organisms -- but a gene for blueeyes doesn't benefit directly if it's linked with (say) a gene for light skin;genes can and do evolve and survive separately. It's hard to discuss this withoutimplying purpose on the parts of genes, which is wrong, but it is crucial tounderstand that each gene is in it for itself; survival of other genes, even ofthe whole species, is incidental to them. The Selfish Gene view, we note,brings evolutionary biology that much closer to textual criticism. Manuscripts, e.g.,do not replicate themselves exactly and in their entirety;they replicate passage by passage and word by word. Usually, if a manuscriptis copied, most parts will be replicated. But note the situation is just likea gene: As a gene is either passed on or not, a particular passage is eithercopied accurately or not. A manuscript may be 99.9% identical to itsancestor -- but any given sentence or word is either 100% identical or ithas been changed.

(A side comment on Dawkins. In recent years, he has gone from avowed atheismto open attacks on religion, up to and including his recent publication ofThe God Delusion -- a book I have not read, and which I think incrediblyunfortunate. Having heard Dawkins talk about it, I know that many of his pointsare valid -- certainly, as one who is trained as a scientist, I know that the Americanprejudice against anyone who even hints of atheism is strong, ignorant, andunfair! -- but I also know that his book is not going to do any good, and thatDawkins should have known it would not do any good. But we must distinguishDawkins the scientist -- author of The Selfish Gene and TheExtended Phenotype and, at a more popular level, The Ancestor's Tale --from Dawkins the militant atheist. Dawkins the scientist is a great man.Dawkins the atheist, at best, is someone who completely fails to understandthe views of the other side. But we'll ignore that Dawkins.)

A strong note: throughout this article, I use the words "if" and"assume" and "suppose"in the mathematical sense: To say "in the event thisis true, that other thing will follow." At no point should this be taken to meanthat the "if" statements imply either belief or doubt on a particularpoint (except the one that is stated above, that evolution is happeningnow, which is a fact and so need not be questioned).

Also, while what follows will make occasional reference to interesting Biblicalparallels, it will pull no punches on evolutionary theory -- e.g. it just assumeshumans are descended from apes, which are a branch of primates, which are a particulartype of mammals, etc. In fact, there is a stemma of human evolution at one point(mostly because the popular treatments of this are so consistently out-of-dateand inaccurate. I can't promise to be accurate, since I'm not a biologist, butmy stemma is based on comparing five books by paleontologists, all publishedwithin the last ten years as I write).

Evolution and Textual Criticism

There are, to my knowledge, at least four scientific/cultural areas whichfollow true stemmatic models: The origin of biodiversity, the differentiation ofhuman language (and, perhaps, culture), the transmission of written texts,and the transmission of oral texts.

Darwin himself was aware of the relationship with languages; he mentioned it inThe Descent of Man. He does not seem to have been aware of the link withmanuscript transmission, but I am not the first to mention it; Daniel C. Dennett,in Darwin's Dangerous Idea, p. 136f., compares evolutionary theory to thetextual criticism of Plato being done at the same time. This article, however, willtry to show how evolutionary theory informs textual criticism, rather than thereverse.

Note that when I say "stemmatic," it means something muchmore specific than the ordinary use of "evolution" and"evolutionary." The latter can be used for, say, "theevolution of nursing home care" or "the evolution of aircraftmanufacture." The latter two are not truly evolutionary; they aremerely progressive -- each step goes beyond what is before. Karl Popper andhis followers would call this evolution, but it is not in any waythe same as what happens in biology. The processof a technology is a series of inventions which do not inherently follow onefrom the other. A true evolutionary process is one where you start froma small population of types or individuals and watch it increase to alarge population of types or individuals, with more diversity, but witheach new individual directly descended from some subset of the previousindividuals. You also see many if not most of the earlier specimensdie out -- and, potentially, you see certain traits die out with them.We must stress that that, in biology, evolution is not progress; it's justchange -- or even, in some cases, a lack of change.Evolutionary success, in an ironic way, consists in not evolving;it means a species has successfully found a niche in which it can survivefor a long time. Evolution does not have a goal, so it cannot makeprogress. Whereas aircraft manufacture has a specific goal: Optimizing cargocapacity and speed while minimizing cost of manufacturing, maintenance, crewsize, and fuel. Yes, one or two of these may be more important than others --if fuel is cheap, energy efficiency is a low priority; if fuel is expensive,good "mileage" becomes vital. So there is some selective pressure.But the point is, it's directed pressure, whereas evolution is a sortof vector sum of all the conditions in the environment. The two are simply not comparable.

Evolution is what happens when a population is capable of reproducingindefinitely -- when numbers grow and grow and grow. You can easily see sucha population explosion at home (I lifted this idea from Daniel C. Dennett):Put a little yeast in bread. As Paul said, alittle yeast leavens the whole lump of dough -- and, if you take a little ofit and mix it with another lump of dough, it will leaven that, too.

For a while. If you notice, a loaf of bread will not rise indefinitely.It runs out of sugar, and the yeast run out of food and shut down.

It was Thomas Malthus, not Darwin, who discovered the key point: That there is alimit to population expansion. The most basic laws of the universe -- thelaws of thermodynamics -- say that anything which uses resources (which iseverything) will eventually run out of something. Population cannot expandindefinitely. At some point, something will act to limit it.

But Malthus said nothing about which reproductive lines would survive andwhich die out. For him, in effect, extinction was random. It was Darwin whorealized that this was not so. The creatures which could survive best inconditions of scarcity would be the ones which survived. Malthusian populationcontrol was essentially random. Darwinian was not -- it picked out thestrongest lines and let them survive and expand. Thus is became a stemmaticprocess: Everything traces back to the handful of surviving ancestors whichbred best.

The analogy to the New Testament is obvious. Take, say, the fourth century.There were many manuscripts then, including B. Yet it appears that B left nodescendants (other than the peculiar case of 2427). The ancestor(s) of thecurrent Byzantine text do not appear to have survived -- but they must haveexisted (even if they didn't look much like the current Byzantine text).

There are still other processes which are evolutionary -- even stemmatic --without following the course of biological evolution.Musical genres are an example. Early Britishfolk music has left a number of descendants: Modern British folk in England,New England folk music in, well, New England, southern folk music in theAmerican South. The latter is now called "Country music" -- and itin turn has spawned offspring. The early country is now called "oldtime country." This was succeeded by "classic country,"in which electric instruments began to replace acoustic and the songswere more often composed than traditional. This in turn has been succeededby pop country, which has very little old-time influence at all, is almostentirely electric, and which is much more centered in contemporary thanin timeless themes; almost no one likes both old-time and pop country. Theevolution, and even the stemma, is clear -- but the old generations have notdied off. Old-time country is not very commercially successful, but it endures,and today's performers are actually more technically proficient than the oldermusicians. (And, in a deep irony that bears real thinking about, the modernperformers, all of whom are deeply devoted to the forms and styles of the past,are consistently liberal, often to the point of radicalism, while the morenumerous fans of pop country, a musical form mostly invented in their lifetimes,are the most reactionary conservative population in the United States.)Old music forms are not replaced by new; the market just gets morecrowded. This is unlike biological evolution, where all creatures die, andrather unlike even manuscript evolution, where a few last a very long time butmost eventually are destroyed.

Even the four processes I specified (living creatures, texts, languages,oral traditions) are different in some regards. Living things, for instance,have genes, which restrict their ability to evolve. A creature with genescan only evolve by Darwinian evolution. Processes without genes can sometimesbe altered by Lamarckian evolution (in which they acquire desirable traitsdue to desire or an external force and then pass them on). This is relatedto the fact that biological evolutionhas no (observed) "editor," whereas a text or a traditional folksong can be subjected to deliberate redaction. Then again, where awritten text can sometimesbe recalled and corrected, an oral text can't. Still another differenceis that livingcreatures can generally reproduce on their own; texts require outside assistance(a copyist). This, in a way, resembles the reproductive cycle of a virus.

Another important point of comparison manuscripts and living creaturesis parentage. Creatures which reproducesexually (which includes almost everything we think of as an animal, and mostlarge plants) have two parents. They have inherently mixed ancestry. Thiscontrasts to most of the other processes. Languages are rarely very mixed (thoughEnglish, with its Germanic base and its heavy Norman French overlay, is infact a mixed language). Biblical manuscripts are, almost without exception,mixed, but the mixture is intermittent: Most of the transmission stagesin a manuscript's ancestry involve only one parent, but at various times, individual generationswill have two, as a text is corrected from a different manuscript than theone used to copy it. This is unlike animals, but quite like a lot ofplants, such as strawberries or elms: They sent out clones of themselves,by runners or the like, but also reproduce sexually at times. (It has beenspeculated, though I don't believe it's been proved, that most of thesedual-reproduction species use the two methods differently: Cloning is forpopulating the local area as much as possible, since the plant's own geneshave been successful in that environment. Sexual reproduction, which mixesgenes, is for sending seeds out far and wide, where a different combinationof genes might be more successful.)

Thus every one of the four processes has its own characteristics, andthe differences are often much more important than the similarities. TextualCriticism, for instance, is trying to look back to the original document.Evolutionary biology seeks to explain present creatures and perhaps predictwhat will come next. But each can, potentially, inform the others. There areplenty of parallels, from the crucial to the trivial (e.g., just as oldmanuscripts are sometimes cut up to be sold in pieces to collectors,sometimes fossils are broken so that the fragments can be sold in piecesto archaeologists).

I will admit that my thinking about this was sparked by readingThe Ancestor's Tale by Richard Dawkins. I had already known thatbiological evolution had parallels to textual -- but Dawkins kicked up somany interesting analogies that I decided it was time to bring them intoTC as best I could. Which probably isn't very well, since my training is inphysics, not biology. But maybe it will point the way for someone else.

Where possible, I express as what follows as questions,since in some places the parallels are partial, and in others no one haseven looked for parallels.

I already noted one of the key points about biological evolution: Thatit proceeds through genes. Genes are, in some regards, crucial: A personwhose parents both have type O blood, for instance, cannot have typeA or type B blood; the genes aren't there. And the only way one can createa new blood type -- "Type C," let us say -- is by mutation. Suchdramatic mutations are much more likely to be fatal than to give rise tosomething new and useful, or even new and neutral.

Are mutations, then, the analogy to scribal errors? A lack of analogy liesin the way they are treated. A single scribal error will almost certainly not befatal to the manuscript. The possibilities are not that it will be kept orthrown out, but that it will be corrected or it will not. If it is corrected,the error will not propagate. If it is not corrected, it still may notpropagate -- if it makes nonsense, it will be replaced with something else,though this correction may not be the same as the pre-error reading.

Genetic mutations have another interesting trait: Those which survive come in two types.Some mutations are "founder mutations," others are "hot spotmutations." A "hot spot mutation" is a gene which is particularlysusceptible to damage, in which case the mutation can happen again and again.The disease achondroplasia, which results in dwarfism, seems to stem from this.Hemophilia, too, apparently -- the hemophilia gene Queen Victoria spread aroundEurope is believed to be a mutation she herself suffered, since none of herparents' relatives appear to have been carriers.

Other mutations are believed to have happened only once, with a "founder"who passed them on. Sickle cell trait is a likely example of this: Someone developeda single copy of the gene -- and was advantaged, because sickle cell trait helpsprevent malaria. So that person (probably African) left many descendents (none ofhis or her children would have sickle cell anemia, note, because the other parentswere free of the trait. The first chance for sickle cell disease, as opposed tosickle cell trait, to appear would have been in thegrandchildren, and that only if siblings mated; in practice, it was probably atleast four or five generations before the first child with sickle cell anemiaappeared. And by then the gene was widespread -- and odds are that no one couldtell where the disease came from, even assuming the culture believed in inheritabledisease, which few did).Mixing within chromosomes

Biologists now are using founder mutations to try to trace the age of particulartraits. They do this by comparing the DNA around the mutated site: the moresimilar DNA the carriers of the trait have, the more recently it must have developed.The illustration at right shows this: The first strand of DNA (the mostly-redvertical line on the left) is the DNA of the original chromosome in which themutation happened. Red DNA (plus the blue mutation) comes from that original mutatedindividual. DNA of any other colour is from someone else. In generations followingthe first, the chromosomes mix, with more and more non-red DNA becoming part ofthe daughter chromosomes. But they mix only slowly, with typically only a fewmixes per chromosome per generation; most genes stay with their chromosomalneighbors in any given generation. As time passes, you have more and more swaps, so thatless and less of the DNA near the mutation stays with it. (The black linesin the drawing show the common DNA in each generation. Note how much more thereis in the middle generation than the final generation.)By comparing the DNA of several people with the mutation, and seeinghow much DNA they have in common, one can estimate the age of the mutation.Textual critics do not have this sort of "clock" for variants, but certainlythe types of variants will be familiar. "Hot spot" variants are those whichcould occur to scribes individually -- h.t. errors would be an obvious example.Assimilation of parallels could also occur this way (this may even be the reasonfor the claimed existence of the "Cæsarean" text-type), and maybethe expansion of Christological titles. But a radical change like adding the longer ending ofMark must be a "Founder mutation" -- someone wrote it, and it stuck.(Note incidentally that we cannot always tell which type a variant is just bylooking at the variant: In the case of Mark 16:9-20, it is a founder mutationif the longer ending is not original, but if it is original, and wasdeleted, it might be a hot spot mutation, lost in several copies of the booksince it was near the end of the scroll. In biology, we can usually tell whichform is original. Perhaps less so in textual criticism.)

(Even ancient founder mutations, which are old enough to have very littlecontext left, can sometimes be dated -- in mitochondrial DNA. Nicolas Wade,in Before the Dawn, pp. 106-107, tells of the work of Martin Richardson populations in Europe. He created a family of DNA mutations -- a relativelystraightforward task -- and then noted the order in which mutations "joined."This gives him the ability to approximately date them. This technique couldpresumably be used in dealing with unmixed local texts. It is less obvioushow it can be used in mixed texts. The fact that Richards applied his techniqueonly to mitochondrial DNA, which does not mix, is significant.)

The obvious analogy to the splicing together of chromosomes is blockmixture, though there might also be some analogy to the case of differentscribes writing different parts of a manuscript. They will at least makedifferent sorts of spelling errors, even if it doesn't affect the text-type.

There is another key similarity between genetic and textual mutations:A change in a single gene in the genome of a living creaturedoesn't affect anything else (at least directly). Similarly, a change in aparticular reading does not change the rest of the overall text. (This is unlikelanguage, where a change in grammar at least will affect the whole language,and also unlike oral tradition, where the loss of a line or two of textmay force a major reshaping.) The real difference lies in the fact that geneshave boundaries; texts don't. Scribes copy in all sorts of ways -- letter byletter, word by word, phrase by phrase. Something that is a genetic unit toone scribe won't be to another.

Still, the fact that scribes copy in pieces brings us to an interestingpoint. Different stretches of text can in fact have different ancestry. Thefamily tree of a passage need not be the same as the family tree of themanuscript as a whole.

Dawkins refers to this as the "historical" and "genetic"ancestors.

Turning to one of our parallel disciplines, we can turn to the folk balladknown as "Barbara Allen." This is probably the best-known song in thehistory of the English language, having been collected roughly 1000 times (andas a result, I've used it in several examples, notably in the article onoral transmission). Two folklorists, Charles Seegerand Ed Cray, once set out to examine its ancestry. Seeger looked at the tunes,Cray the texts, and they did not compare their results until they had done theirbasic classsification.

Seeger found that the song had four basic tunes. Cray found that it had fourbasic text-types. It is logical to assume that the two arose separately -- thatis, at one time, text-type A had a particular tune associated with it, and text-typeB had its own tune, and so forth.

Not any more. Texts and tunes are completely dissociated. (It has been shown inother contexts that people frequently swapped tunes for songs.) Although any particularversion will presumably go back, without much mixture, to one of the early song groups(the historical ancestor) it may well have derived its tune from another group(the genetic ancestor).

To take an example of how this works in biology: Most genes are passed viamixture: You can get them from either parent, and so you can't tell, just bylooking at the end product, which ancestor supplied a particular gene. Butthere are two exceptions: Mitochondrial genes, and Y chromosomes.

We already mentioned mitochondria once; let's talk about that a little more.Mitochondria are the cells-within-cells that supply the power used to runthe rest of the cell. They are found in all cells -- but the father's spermdon't transmit them to children; only the mother's eggs do that. And mitochondria havetheir own DNA -- just a handful of genes, but they are genes.So every child gets his mitochondrial DNA from his or her mother,and from her mother before that, and her mother before that, and so on forever.Theoretically, it all goes back to a hypothetical first mother. (In fact, itappears that there is a first mother, from whom all humanmitochondria are descended. She is called "Eve," naturally, andis estimated that she lived about 140,000 years ago.)

Incidentally, the tracing of mitochondrial DNA gives evidence, stemmatically,that the origin of humanity was in Africa, or at least that there was a chokepoint in Africa from which all later humans descended. This is shown by a stemmafirst published in Nature in 1987 (I found it printed in James Shreeve,The Neandertal Enigma, p. 56). It's so complicated that it is printed asan arch, with 135 data points arranged in a tree. But let's take only its firstfew branches and see where they lead. Note that each branch is a genetic variant:Either your mitochondrial DNA has one reading or it has the other. Barring coincidentalagreement (i.e. two pieces of DNA suffering the same mutation, which is possible butunlikely), this gives an absolute stemma. At the end of each branch, I show the continentswhere it is found: Af (Africa), As (Asia), Au (Australia), NG (New Guinea), Eu (Europe).

     "Eve"       | -------------- |            | A            B |            | |      ----------------- |      |               | |      C               D |      |               | |      |      ---------------------------- |      |      |           |              | |      |      E           F              G |      |      |           |              |Af     As     Au    Af,As,Au,Eu,NG    Af,As,Au,Eu,NG

Now it must be stated that this stemma admits of two possible interpretations,depending on how we root the stemma: First, that the B version is theoriginal, probably in Asia (since that's the place common to C and D), with humanityspreading from there; second, that the original sequence (which could have been A orB; we cannot tell) originated in Africa, and split there, with only a small populationof B migrating into Asia and hence into Europe, Australia, and so forth. Other dataseems to at least partially support this interpretation; according to a study describedin the October 2010 Scientific American, a study of several genes found that mostalleles fell into one of three possible pattens: They are found in all populations outsideAfrica but not in Africa (the "Out-of-Africa sweep"), or they are found inEurope, the Middle East, and the Indian subcontinent (the "West Eurasian sweep,",which to me looks like the sweep of Indo-European), or they are found only in China andEast Asia, Australia, the Pacific and Indian Ocean Islands, and in the natives ofthe Americas (the "East Asian Sweep") This implies a branch point between Africaand Asia, another somewhere around the Caspian Sea, and a third in China, but with themost fundamental being the Asia/Africa split. This is,ultimately, the Bédier Problem of atwo-branch stemma -- but in this case there is so much variation in the descendants of A thatthe biologists think the point of origin must have been in Africa.

Just as mitochondrial transmission is exclusively in the female line,the Y chromosome is exclusive to males, meaning that any mangot it from his father, and his father's father before that, and so on backto the beginning. As with mitochondrial DNA, the divergences inits DNA can be diagrammed. This points to an "Adam" wholived about 60,000 years ago.

To console the creationists, we note incidentally that this does notautomatically mean that there cannot havebeen a contemporary Adam and Eve, though it obviously seems unlikely.The Biblical Adam and Eve, ifthey existed, were the earliest common ancestors of all humanity.The "Adam" and "Eve" of the molecular biologists are,respectively, thelast common male ancestor of all males and the last common femaleancestor of all humans. There is no inherent reason they should live atthe same time. The following genealogyshows how this could happen, where s01, s02... represent unnamed sons,d01, d02... represent unnamed daughters, and === represents a marriage.

                Eve === Adam                     |         ----------------------------         |        |         |       |        Seth === d01       s01 === d02              |                 |           ---)--------------------------           |  |         |               | ----------)------------)--------       | |         |    |       |       |       |Enosh === d03  s02 === d04     s03 === d05     |              |               |    ...all produce many more children...

Now observe: If you trace all the children back in female line, some aredescended from d01 and some from d02. Thus their most recent female ancestoris Eve. But every male offspring is descended from Seth, via Enosh, s02, or s03.Their most recent common ancestor is Seth, who lived later than Eve. Thisdoes not mean that s01 had no descendants; he has as many as Seth.But, because they were all daughters, his y chromosome is extinct;only Seth's is preserved. In fact, were this genealogy correct,Seth's X chromosome would also be extinct, because he had only sons,but we can't prove that because we can't trace the genealogy ofX chromosomes as we do Y.

For that matter, we would note that, if the Biblical account is literallytrue, then the last common male ancestor cannot be earlier than Noah (sinceall males who survived the flood were his sons), but the females must go backsome time before that. Personally, I find that kind of spooky, since it matchesthe Biblical results (except for the fact that the time periood is much longer).

(Though another possible explanation should be noted. If we look at history,when one people conquers another, the tendency is to kill all the males andtake the females -- at least the pretty ones -- as slaves and concubines. Thusa tribe's mitochondrial DNA can survive when its Y chromosomes are extinguished.If warfare was sufficiently common at an early period, then we would expect tosee the ancestral Y chromosome to be at least as recent, and perhaps more recent,than the ancestral mitochondrial DNA.)

This has other implications for Biblical history: Dean Hamer'sbook The God Gene, chapter ten, "The DNA of the Jews," startingon page 180, tells of a study of the Jewish "Cohens" -- the people whoclaim to be the descendents of the ancient Aaronite priestly family. The study seemsto reveal that they really are a family: based on the Y chromosome data,the "Cohens" almost all derive from acommon male ancestor who lived at least two thousand and possibly as much as3250 years ago. In other words, the modern Jewish priestly lines go back atleast to the end of the Second Temple era, and possibly even to the period ofthe Judges or the end of the Exodus. We can't prove that the common ancestorwas Aaron or Eleazar -- for all the data proves, it could be Simon Maccabeeor even, theoretically, Annas or Caiaphas -- but it proves that these peopleare indeed descended from one common ancestor.

We can go beyond this. Just as, ultimately, there can only be one autograph ofa New Testament book (or, at least, only one first draft, since the author may havepublished multiple editions), there must -- by virtue of the fact that humanshave not always existed -- be a human being who is an ancestor (not theancestor, but an ancestor) of all future human beings. This process has beenstudied a great deal; Dawkins talks about it on pp. 42-44 of The Ancestor's Tale.It can also be shown that, if we go back a certain number of generations, everyperson (and so every manuscript) is either the ancestor of all manuscripts or isan ancestor of none -- and, in a typical population, more of those who reach breedingage are ancestors of all than are ancestors of none. We'll see more implications of this below.

Most reproductive processes have this phenomenon of earliest and latest commonancestors. For mammalian life, it's likely that the earliest recognizable ancestor is someancient creature that was the first eukaryote (that is, the first being witha clearly delineated nucleus, mitochondria, and other characteristics of moderncells). But the common ancestor even of such seemingly-unrelated creatures ashuman and trees is probably more recent than that -- in the case of, say, humansand apes, it's much more recent.

Similarly with languages. German and English, for instance, have a knowncommon ancestor in proto-Indo-European, thousands of years ago. But theirmost recent common ancestor is Old Germannic (or whatever you want to call it),and the two diverged only about 1500 years ago. And even after the divergence,they were still mutually comprehensible for some hundreds of years, and probablyswapped a few new words.

In the case of literary texts, the analogy is in this case quite exact:the earliest common ancestory is the autograph, while the latest is thearchetype. The analogy is precise in another way,too: You can only reconstruct back to the latest common ancestor. Theancestors of the Indo-Europeans surely spoke some language. But we can't reconstructit (at least until we can bring still more languages, which divergedearlier, into the Indo-European family tree). In the case of language, we can'teven prove that there was a single original language; many linguists thinkthere was, but this strikes me as a little strong; the divergence in styles oflanguage is so great that it strikes me as quite possible they came about afterthe earliest population had split (i.e. the language capability was there but initiallyunused). With such uncertainty, we surely cannot recreate the "originallanguage." All we can do is recreate proto-Indo-European, the language as it wasspoken at the time of the first split in the family.Similarly, if the archetype is more recent than the autograph of a particularliterary work, you can only reconstruct the archetype; beyond that, all isconjecture.

We note incidentally that the reconstruction of language can often interactwith other rather stemmatic disciplines. Staring in the early 1960s, Joseph H.Greenburg began a systematic attempt to link all languages together intofamilies. His success has been mixed; very many linguists now accept his resultsfor the "Afroasiatic" superfamily (consisting of the Egyptian, Omotic,Cushitic, Berber, Chadic, and -- notably for our purposes -- Semitic families),but they are less sure of his other results. The interesting point is that hisresults have often been correlated with other sorts of data, such as DNA evidenceof people. (See Nicholas Wade, Before the Dawn, pp. 218-232.) I find myselfwondering if we might not learn something by trying, say, DNA analysis of the parchmentfrom various manuscripts.

Population genetics has had other interesting results which might affect ouranalysis of the New Testament tradition. A detailed comparison of the populationof Iceland showed two interesting things, both of which affect the claim of"normal transmission" proposed by the advocates of the Byzantine Text.One is that not all populations reproduce at the same "generational speed" --in Iceland, the average interval between generations was 29 years for females, 32 formales. Presumably this is because females marry younger, but still, populationsclearly do reproduce at different rates. In addition, the work of DeCode Geneticshas shown that 92% of Icelandic women born since 1972 were descended from just 22%of the women born 1848-1892, and 86% of men born since 1972 were descended from just26% of the pre-1892 group. It has long been suspected, mathematically, that populationsreproduced this way; now it has been shown empirically (see Wade, p. 244).

But it needs to be repeated that "common ancestor" is a sort of a relative term,because genetic and historical ancestors may be different. This is true in twodifferent senses. One is genetic reduction: A human being or other creature inheritsonly half his chromosomes from either parent. So if our Ancestor is A, his childA1 has exactly half his chromosomes. A1's child A2 has only, on average, half ofhalf, or a quarter of A's genes. A3, the child of A2, has only an eighth, A4 hasonly 1/16, A5 has only 1/32, A6 has only 1/64, A7 has only 1/128, and so on.

But note that human beings have only 46 chromosomes. 1/64 of 46 chromosomesis less than one; 1/128 of 46 chromosomes is less than half a chromosome. In otherwords (barring reinforcement by inbreeding), after seven generations, odds arethat an offspring shares no chromosomes with any random ancestor. The samemight well be true of a text that has been through enough stages of mixture: Itmight have an Alexandrian ancestor, say, but after enough Byzantine corrections,it's no longer possible to tell. Each generation of mixture has taken more ofits Alexandrian-ness away.

(Note: The above statement is very oversimplified. Chromosomes in fact arenot conserved across generations. As noted above, except for sex chromosomes in males, thechromosomes swap genetic material from generation to generation -- a phenomenon knownas "crossing over." It is thought that the purpose may be to control avicious genetic phenomenon known as "segregation distorters," -- genes whichtry to hog reproduction by making themselves more common than the alternate genes onother chromosomes. Since such genes usually aren't good for much else except making themselvescommon, they are dangerous to all the other genes, and so the system uses crossing overto try to break them up. This is onereason why human chromosomes are so chaotic, with parts of singles genesscattered all over the place. It may also be why the X chromosome is so much largerthan the Y chromosome: The Y chromosome contains genes not found on X -- those geneswhich make a person male, obviously -- and so cannot cross over. This means that thereare wars between X and Y genes -- and the X genes tend to win, because there are threetimes as many X as Y chromosomes out there. So the Y chromosome now has almost no genesleft except those needed to make males. But while crossing over is very important for actualevolution and molecular genetics, it concerns us not at all. The only thingwe need to remember is that one can be descended from a person without havinga single gene derived from that person. It sounds insane, but it is not. Therelevance is this: Manuscripts which are the result of mixture reproduce in thesame way as genes: Some parts come from one parent and some from another. Given enoughgenerations, there may be no readings left which derive uniquely from theancestral manuscript. An Alexandrian ancestor can be mixed to the pointwhere its offspring becomes purely Byzantine, or vice versa. It doesn't even takethat many phases. Given the level of correction found in, say, C, it would takeonly about four generations to go from Alexandrian to Byzantine.)

The other part about genetic and historical ancestors can perhaps be illustratedby using blood types again. Human beings have two major types of blood clottingfactors, A and B; the absence of these gives type O blood.

But, interestingly, it has been shown that chimpanzees also have typeA-B-O blood. I've also seen it stated that gorillas have A-B-O blood, but I haven'tseen this confirmed. I've found the A-B-O split in chimps stated in several places.(Matt Ridley, on page 26 of The Agile Gene, states that chimps have types A andO blood, while gorillas have type B. The stemmatic implication, obviously, is thatthe common ancestor of humans, chimps, and gorillas already had types A, B, and O.)No matter what the exact distribution of clotting factors, it is clear that theevolution of the factors predates the split betweenhumans and chimps, thought to have taken place about six million years ago. Ifthe report about gorillas is true, then the A-B-O split took place one or two millionyears before that.

Now compare this to the dates for "Adam" and "Eve" givenabove. The blood type split, since it goes back six million years, is at leastthirty times older than Eve. And, as regards blood type, one can be more relatedto a chimp with one's own blood type than with a human of a different blood type.For example, I am type O. I share the genes for clotting factors with all type Ochimps -- and I don't share them with you if you are type A, B, or AB. (Note:Because type O is a recessive, that's not entirely true. If you are A or B, I mayshare one type O gene with you. But I may not. And if you're AB, then I know I don'tshare any genes with you.) Although I am historically descended from human beingsand not from chimps, as regards blood type, I am more closely related to somechimps than I am to some people.

Note that, again, this does not require some descendant of "Eve"to have mated with a chimp or the like. If "Eve" had, say, A-O genes,and "Adam" had B-O, or Eve and Adam had OO and AB, or vice versa, then theblood types could all be descended directly from them. That's the whole point:We aren't talking ancestry but common genes. Because of the genetic reduction --which can become genetic drift -- with regard to a particular gene, I may beunrelated to "Eve" or "Adam" -- or even both.

An even more obvious example of this is the distinction between male and female.Different creatures have different ways of determining sex -- among some fish andreptiles, it's dependent on environment, e.g. But in mammals, it's genetic. Thereare a handful of Y chromosome genes which cause maleness by turning on a few switches.This is universal in all mammals. Thus, if you are male, the basic genes to make youmale have to go back all the way to the earliest mammals, if not earlier. In regardto those genes, you are closer to a male rabbit or horse than you are to a femalehuman. Patently absurd in an overall way -- more than 97% of a male's genes arefound in female humans, and they aren't found in horses or rabbigs -- but true forthose specific genes.

The analogy to text-types is interesting. If a manuscript mixed in a foreignelement, that element is more related to the source of the mixture than thehistorical ancestor. So, for example, "John 7:53ffff." probablyoriginated in the "Western" text-type. But it's found in somemanuscripts which are otherwise mostly Alexandrian. Chances are that it wasintroduced by mixture, and that that passage, even in L or 579 orwhatever, is genetically "Western," not Alexandrian.

This invites a very different way of looking at stemmatics. We tend to thinkof genealogy in a top-down sense, with an autograph, then various copies, andcopies of the copies, down to the manuscript. And we may think of the manuscriptas being derived from a variety of sources going back to the original -- a bottom-upapproach.

But in light of DNA descent, we might have to think of this in differentterms. Each manuscript has a historical descent which takes it backto the autograph. But each reading can have a different descent.

This may sound a bit like the Alands' local-genealogical method. It is not. A betteranalogy might be to a train: Each car on the train comes from a specific place --but not always the same place. Indeed, each of the cars may contain packages from multiplesources. The model we see is much more three-dimensional thanour traditional view. Each reading has a specific path back to its origin (which maybe the autograph or may be a corruption). The diagram below may give some idea ofthis. There are three text-types, called by Greek letters but shown as red, green,and blue. At the bottom we have a particular manuscript with a particular set ofreadings, all derived from one or more of the three types.

This picture can make life look despairingly complex. Complex it is, butthere is hope. Because we can demonstrate that every manuscript has acommon ancestor. Somewhere. It may be the autograph. But it's there.Similarly, every reading has a common ancestor.

Take each readings in the final manuscript individually. Reading 1 is has red andgreen ancestry. Reading 2is red and blue. So is reading 3. Reading 4 has influence from red, green, and blue.Reading 5 is pure green, reading 6 pure red. If we chart this, we find that each of thetext-types contributed to certain readings:
RED: Readings 1, 2, 3, 4, 5, 6, 8, 10 (total of 8 readings)
GREEN: Readings 1, 4, 7, 8, 9 (total of 5 readings)
BLUE: Readings 2, 3, 4, 9, 10 (total of 5 readings)

Note that no type contributed to all of the readings. But consider red, with influencein eight out of ten readings (including two, #5 and #6, which are purely red). It issafe to call this a "red" manuscript. When we are in doubt about a particularreading's origin, it is not a bad bet to assume that it's red, though the matter is not certain.We just have to understand that a manuscript of a particular type may have readings notof that particular type -- as a person of Scandinavian origin might have inherited afew genes which go back to the Middle East or China.

This is the solution of the seeming paradox above, that, if we go back a certainnumber of generations, every manuscript is either an ancestor of all manuscripts nowsurviving, or of none, and more were ancestors of all than of none. Of the first fewdozens copies, most -- if not destroyed without being copied -- would have influencedsurviving manuscripts. They would be historical ancestors. But would they havecontributed significantly? Probably not. It's quite possible that a manuscript of aseparate text-type (say the Greek that underlies one or another Latin or Syriacversion) could have influenced all our modern manuscripts -- and not have a singleone of its unique readings survive! Obviously this could affect how we view ourparticular collection of mixed manuscripts....

To this peculiar-sounding propositionwe can also compare the ancestry of books in a corpus. The earliest copiesof the Pauline corpus, for instance, came together before all the books wereaccepted as being part of it. (Hebrews obviously was not included in some earlycopies; compare also the contents of P46.) Might books whichcirculated on their own andwere eventually added to a corpus have gone through a history unlike the otherbooks in the later copies of the corpus?

This brings us to another problem that doesn't get much thought. Most peopleagree that text-types exist, though they disagree on how to use them. But when andwhy did they come to exist? This is more complicated than saying, "The Byzantinetext was in existence by the fifth century." If we ignore the effects of mixture,there was some point at which any two text-types split -- that is, there was somemanuscript of which we can say, "This is the ancestor of all Byzantine (orAlexandrian, or Western) texts, and it is not the ancestor of all non-Byzantine(or non-Alexandrian, or non-Western) texts." But that manuscript will be closelyrelated to other texts of which this is not true. It may be the ancestor of allByzantine texts, but it is not itself characteristically Byzantine! So should it becalled Byzantine?

Dawkins gives an analogy of this in terms of the transition from monkeys to apes.The usual distinction between monkeys and apes is that monkeys have tails. At somepoint, a female monkey bore an offspring which would be ancestral to all modern apes(and humans). But that ancestral creature, the offspring of a monkey, surely had atail. It was, to all appearances at least, a monkey -- and surely still capableof breeding with other monkeys. At what point did that lineage become apes? When thetail was lost? What if the tail was lost gradually -- there are a lot of monkeys withshort tails. There is no answer to this. It merely teaches us an important rule aboutevolution: That trends and processes are more important than the staging points alongthe way. We call the ancestors of humans by names such as "homo habilis" and"homo erectus." But these actually represent more a trend than anything else --a trend toward bigger brains. There is no place or time at which you can halt and say,"This is completely different from everything that came before or after."Does this affect how we use manuscripts? Probably -- because every manuscript, exceptthe autograph, is just a stage in such a process. It's a fossil representing a stagein the history of transmission. It is not the beginning, and not the end. The goalis presumably to see where it points.

In this context, it's worth remembering that evolutionary steps consistentlyhappen one at a time, and each has to be a reasonable step in the process.You did not, for instance, have a fish step out of water and instantly develop twolegs and two wings and become a bird. No, first it had to become a reptile, withfour legs, then as a secondary change, the two front legs became wings. This is informativewith respect to a reading such as 1 Corinthians 13:3, where the readings areκαυχησωμαιorκαυθησομαιorκαυθησωμαι. Most editors havepreferred either the first or the second -- the first on the grounds of its externalattestation, the second on the grounds of its suitability. But it is important tonote that it takes two changes to get from one of these to the other --an exchange of χ/θ and an exchange of ο/ω. Thismeans that one or the other of the two preferred readings must derive fromκαυθησωμαι.Eitherκαυθησωμαιis the original, and the other two readings direct modifications of it; orκαυχησωμαιis the original, perhaps accidentally changed toκαυθησωμαιand then deliberately corrected toκαυθησομαι;orκαυθησομαιis original, and was miscopied asκαυθησωμαι,then corrected toκαυχησωμαι.That last process strikes me as most improbable (who would correctκαυθησωμαιtoκαυχησωμαιrather thanκαυθησομαι?).Thusκαυθησομαι,though widely printed, is in fact a very nearly impossible reading, simplybecause evolution must proceed one step at a time.

Another interesting analogy to Paul exists in the case of the human chromosome 2.It is a curiosity that apes consistently have 48 chromosomes, but humans have only46. It is now pretty well established that the reason is that our chromosome 2 (whichis, of course, the second largest in the genome) is in fact a combination of twoshorter ape chromosomes. In this sense at least, humans are different fromapes. Compare this to 2 Corinthians, which certainly appears to be fragments oftwo or three or four letters squished together.

The assembly of books into a corpus, or of separate letters into a sort of awhole, incidentally has another evolutionary parallel, though this is much morespeculative. One of the great problems of biology is to explain how the currentsystem of our cells came to be. We have a controlling mechanism, the DNA, which storesthe information needed to create and control a cell -- but which is useless foranything else except information storage. We have a bunch of proteins, many ofthem enzymes, which can actually do things, but which cannot store information orreproduce. For life to come about, at first glance, it would appear that these twowould have to come into existence together -- the so-called "irreduciblecomplexity" argument.

Which is, however, false. The argument is false in general, because it ignoresthe usual trend of evolution, which is toward simplicity (that is, natural selection sheds allunneeded features; if something is truly irreducibly complex, odds are that it isat the end of a long chain of evolution based on less effective, more complexmethods). And it is false in this particular case because it appears to ignore howlife started. The goal is to find a "naked replicator" -- the originalmolecule that could make copies of itself. Neither DNA nor proteins fit thisdescription; they're too specialized.

But there is another molecule found in nucleii: RNA. While we can't prove it (yet),it appears likely that RNA was the original replicator. Unlike proteins, it canreproduce -- although inefficiently and with a lot of errors. Unlike DNA, it actuallyhas some ability to act on its environment -- indeed, the ribosome, which converts DNAsequences to proteins, contains RNA as well as protein, but no DNA. And it is RNA,not DNA, which transmits the actual sequence of proteins to be encoded.

This is notably significant, because most of this process has been recreatedin the laboratory -- that is, people have recreated the conditions on the earlyearth, and added energy. The first experiments of this type, in the mid-twentiethcentury, quickly yielded amino acids. More recently, we've started to move towardan actual RNA factory (see Matt Ridley, Genome, pp. 18-21; in addition, Dawkins,in The Blind Watchmaker, p. 190, tells how Manfred Eigen evolved RNA in thelab without any influence from existing life, though he started with raw materialsslightly more complicated than just the carbon dioxide, water, methane, and such ofthe amino acid experiments. According to John Maynard Smith, The Theory ofEvolution, pp. 9-11 of the 1993 Canto edition, an even more interesting aspectof this process is that, when run several times, it produces similar but not identicalend results, showing that natural selection does operate to favor the same typesof results but not the same exact results). Add it up and it's clear thathumanity has recreated something pretty close to a modern virus: Some viruses(called, for obvious reasons, RNA viruses) haveno DNA, just RNA and protein. Modern viruses probably don't go back to the days of the"RNA World" (there wouldn't have been anything for them to infect),but our recreations are very likely similar to life forms of that era.

Incidentally, Dawkins, The Ancestor's Tale pp. 576-578,describes an experiment undertaken by SolSpiegelman on the RNA of a bacteriophage (virus which infects bacteria)called Qβ. Spiegelman not only caused its RNA to reproduce without abacterium (indeed, without parts of the original virus), but he induced it toevolve. The final RNA strand was only a seventh of the size of the original, andno longer had the genes to invade bacteria -- but it could reproduce faster andmore effectively in the lab setting Spiegelman had created. It was, by any rationaldefinition, a new species.

Turning back to ancient history -- having created those RNA replicators,the next step must have been for them to group themselves together. Afterall, one RNA replicator can only perform one or two functions apart fromreplicating. But if they group, they cancombine to perform multiple functions. This is the analogy to the collecting ofbooks in a library.

And once they are grouped, then it becomes possible to branch out. RNA is nota very good replicator. It's unstable, and inefficient at duplicating, and whileit can influence the outside world, it can't do so very easily. A more stable replicatorand a more complicated set of enzymes would work better. With a bunch of RNAworking together, so that some could do the work of surviving while othersexperimented with replicating, it was possible to make the relatively minorchemical changes needed to turn RNA into DNA. And once that was done, the replicatorsystem could truly take off.

Allow me an analogy. Think of life inside a nucleus as being like a computer.There is memory (DNA) and input and output devices (proteins). It might seem thata computer could not exist without both -- that both had to come into being attogether and all at once.

But it's not true. Think of the first American computer, ENIAC. It didn'thave a display as we'd now think of it, nor a keyboard or mouse,and it didn't have the huge collection memory chips a modern computer possesses.A task was actually wired in, and computed, and the result read off of thestate of the vacuum tubes, or something equivalent. This is the computer equivalentof the RNA universe: It doesn't work very well, but it works well enough that youcan start fiddling with it, adding on a serial output rather than a bunch ofblinking lights, adding a few memory cells to allow stored calculations, and soon. Once you have something that works, it can be improved.

The key in all this is the grouping: There was one sort of evolution beforeRNA molecules came together. It was all very different afterward.

Incidentally, since we're talked about human and ape chromosomes, we can showhow stemmatics affects evolutionary arguments. Recall that humans have 46chromosomes, while apes have 48. How do we decide how many chromosomes the lastcommon ancestor had? If humans and apes split separately (that is, if we have abinary tree, with apes on one side and humans on the other), then we would haveno way of knowing. But it appears on other grounds that the correct stemma isas follows, with surviving species shown in bold and their number ofchromosomes in parentheses. (Note: There is notuniversal agreement on this. Richard Leakey and others still seem to hold tothe view that homo habilis is not derived from the australopithecines butis their contemporary. But he is in the minority, and his theory requires a muchmore complicated genealogy with more "missing links." I don't think itwill hold up. There are lots of other minority theories, too -- one woulddissolve homo habilis. Another would reclassify homo habilisas an australopithecine, which shows mostly how hard it is to define differentgenus. Many would now subdivide homo erectus into homo ergasterand homo erectus, with the former being perhaps the ancestor of modernhumans and the latter an extinct offshoot. Many would put homo heidelbergensisbetween erectus/ergaster and the sapiens/neandertal split.Another scheme would convert the robust australopithecines into a separate genus.Consider the stemma below simplified: These are the parts almost everyone agrees on. At leastin outline; homo habilis, e.g., may be"technically" an australopithecine, but it's still the link between theother gracile australopithecines and homo erectus.)

                    ancestral ape (sivapithecus?)                         |     --------------------α-----------------------------------------------------     |                                                                        |     |                                                                        |     β (dryopithecus?)------------------------------------------              |     |                                                         |              |     |                                                         |              |     |                                                         |              |     γ----------------------------------------                 |              |     |                                       |                 |              |australopithecines ("Lucy")              proto-chimp           |              |       |                                     |                 |              | ----------------------            ----------δ-------          |              | |                    |            |                |          |              |gracile             robust         |                |          |              |australopithecines  australopith.  |                |          |              |     |                             |                |          |              | homo habilis                      |                |          |              |     |                             |                |          |              | homo erectus                      |                |          |              |     |                             |                |          |              |     -------------                 |                |          |              |     |           |                 |                |          |              |  homo        neandertals  chimpanzee (48)   bonobo (48)   gorilla (48)   orangutan (48)sapiens (46)

Now look at the five surviving species: us (homo sapiens), chimpanzee, bonobo,gorilla, orangutan. I've labelled four ancestors: α is the common ancestorof all surviving apes and humans. β is the ancestor of humans, chimps, and gorillas.γ is the common ancestor of humans and chimps. And δ is the commonancestor of chimps and bonobos. It is evident that δ had 48 chromosomes.γ is not certain if we look at the offspring -- but we note that δand the gorilla both have 48 chromosomes. So β must have had 48chromosomes, and it is highly likely that γ had 48 chromosomes. And so didα. Hence, 48 chromosomes is the norm for apes. Somewhere between γand ourselves (that is, in the last six million years or so), two ape choromosomes combinedto form our chromosome 2. (I've heard it speculated that this was the moment at whichhumans became human, that is, the creature made in the image of God. Hard to provethat scientifically....) We don't know when it happened -- and our only DNA samples comefrom the post-homo erectus stage, which is probably at least a million years too late to beuseful -- but it happened somewhere. It might be logical to assume thatit came at the homo habilis stage, since that's considered a new genus, but again,nobody really believes those genus designations, so that's no help. Rather thanspeculate too much, I'm just trying to note how stemmatics and evolutionary biologyuse exactly the same rules.

Let's go back and consider one more point regarding genetics and blood types, as regards Adam and Eveand the dominance of the Byzantine text. If one assumes that all blood typesgo back to the ancestors, then the Biblical Adam and Eve (if they existed)must, between them, have had the genes for A, B, and O types. We noted a coupleof ways this could have happened above. There are only a handful of possible geneticpossibilities to allow this situation to survive. The list below shows the twogenes possessed by each of the two parents. (It doesn't matter, in this case,which is Adam and which Eve; just that one parent has each of the gene combinationsshown below.)
Each of these sets of genes would, if perpetuated equally, produce certainratio of A to B to O blood types in the children.Taking the last, for instance,we have 25% A genes, 25% B genes, and 50% O genes. Recall that the O gene is recessive;the only way to have type O blood is to have OO. A and B are dominant, so AA and AOboth give the offspring type A blood; similarly, BB and BO both yield type B blood.So ancestors with the combination AO and BO would yield the followingexpected values for the prevalence of types A, B, AB, and O blood:
A: 5/16
B: 5/16
AB: 1/8
O: 1/4
This, note, is the highest possible probability for type O (or any otherrecessive gene) when there are only four ancestral genes available: One in four,or 25%. Any other combination of genes in the ancestors will give only one personin 16 with type O blood. No matter what the genetic situation, type O should be rarerthan A or B. In fact, we see no such thing: Type O blood is the most common blood type.Different populations vary, but probably about half the world's people have type Oblood, roughly a third have type A, an eighth or so have type B, and a few oddpercent have type AB. We don't know how this situation arose, but presumably it'sin response to some sort of circumstances which have caused differentialselection of blood types.

There is also the curiosity that some populations have very differenttype ratios than the overall world population -- e.g. Scandinavians, I've heard,have a much higher than average rate of Type A blood than the average. Type Bblood is never common, but in parts of central Asia, 30% of the population isType B. On the other hand, Type B blood is so rare in AmericanIndians that it seems likely that it it all due to recent contamination byEuropeans.Another blood factor, the Rh- type, is found in only about a tenthof the world's overall population -- but hardly ever in native Africans, Asians,or Australians. All Rh- blood seems to be derived from Europe, with the mostextreme population being the Basques, a third of whom are Rh-. (This to me raisesthe interesting question of whether Rh- blood might somehow be related to theNeandertals, who were entirely European and lasted longest in areas fairlynear where the Basques now live, but that's entirely another issue.)

Remember that A-B-O, at least, predate the rise of humanity. (I'm not sureabout Rh factors.) That means that the ancestors of any population will have hadaccess to A, B, and O types. Yet there are no Indians with type B blood,as noted, and the various tribes have different ratios of A to O type blood,with extremes of more than 80% of one type or the other. This is an example ofthe well-known phenomenon of "genetic drift" -- in a small population,a particular gene can simply drop out of the gene pool. (Nicolas Wade, Beforethe Dawn, p. 117, reports on a study which appears to show that certain tribeswere genetically isolated for seven thousand years!) Clearly when NativeAmericans came to North America, they were so small a population that Type Bblood died out, and in the closed circles of some of the other tribes, typesA and O came close to doing the same; it may well be that the handful ofpeople with A or O blood in those tribes are due to incidental recent contamination.(This, incidentally, may be one reason why Indians were so easilystricken by European diseases: They had fewer "polymorphisms" of bloodand other traits. According to Matt Ridley's book Genome, p. 141, typeO blood confers some slight resistance to malaria, which could explain why itis relatively rare in Scandinavia: malaria has never been an issue there.A and B, on the other hand, while they leave people more vulnerable to malaria,improve resistance to cholera, with the handful of people with AB blood being nearlyimmune. Having all three blood types around thus confers immunity to a wide rangeof diseases -- not directly for individuals, but for the population as a whole, andif enough people are immune, it's harder for a disease to take hold.A polymorphism is simply a case of different characteristicsamong different individuals, making it harder for a particular invader to preyupon all of them. This particular aspect of genes and evolution probably is not oftextual significance, though it's perhaps an argument for not following onetext-type slavishly, because the textual equivalent of genetic drift will almostcertainly cause at least some good readings to die out in all text-types.)

The moral is clear: Both overall distribution of blood types, and thedistribution within local populations, show different types becoming moreor less common. One simply cannot assume, as Byzantineprioritists sometimes do, that texts reproduce "normally." It mayhappen sometimes -- but it must be demonstrated, not posited.

Looking at genetic differences between species brings up other interestingpoints. It should be noted that there are a lot of genes that function in almost exactly the same way in all mammals, from mouse to human. A mousemuscle cell does much the same thing as a human muscle cell; the differenceis not how muscle cells are made but how many of them each creature has andwhere they are located. Similarly with very many other genes. (This probablyexplains why mice and humans have about the same number of genes. Most genesare muscle genes or blood genes or brain genes or liver genes, for makingmuscle or blood or brain or liver cells; humans and mice make the same parts.There are only a few genes -- the Hox genes and a few like them -- that tell the body where toput a muscle cell or a brain cell or a liver cell. And it doesn't takemore Hox genes to say "make a huge human brain" thanto say "make a small mouse brain"; it just takes differentones, calling for different numbers of cells. Hox genes are found in justabout every animal tested, from humans to mice to fruit flies, and theywork in almost the same way. And even a fruit fly, which has something likea two millionth of the mass of a human being, has about a quarter of the hoxgenes that a human has.)

We might well also compare the relationship between species with the way wegroup manuscripts. Just as animals are divided into species, genuses, families,and so forth, we group manuscripts into families, text-types, and perhaps othergroupings. In this particular case, the various sets of terminology in thedifferent fields have actually informed each other, withCladistics even starting to blur the lines between disciplines.

But, as Dawkins notes (The Ancestor's Tale, p. 399),of all these various levels of biologicalkinship, only one -- the species -- is rigorously defined: If two creaturesinterbreed, they belong to a single species. If they don't interbreed, theyaren't. (Even this gets a little complicated when dealing with creatures suchas bacteria which reproduce asexually, and there are other complicationsinvolving species which sometimes hybridize. But it's a workable starting point.)

The situation in textual criticism is similar: The only certain relationshipsare those involving immediate kin. Parent and child manuscripts are generallypretty clearly defined. (I wish I could say the same of sister manuscripts;they certainly should be clearly defined. But, having seen manuscriptswhich clearly are not sisters called sisters, we can't trust some declarationsabout that level of kinship.)

Just as any biological relationship other than the species is imperfectlydefined, so a textual relationship beyond the immediate kinship level issomewhat arbitrary. Does this, then, mean that there are no other relations?

This can hardly be the case. The exact moment at which species split, andsplit again, and split again is uncertain -- such evidence as we have indicatesthat it is not a rigid dividing line, such that beforehand you have homoerectus and afterward homo sapiens, or beforehand a genericcat-like creature and afterward a lion. The distinction is clear nowonly because all the intermediate creatures -- the semi-lions and theintermediate-between-homo-erectus-and-sapiens have vanished. (Which adds tothe confusion regarding manuscripts, since manuscripts of all ages survive.Biologists have only a few fossils. We have fewer manuscripts than we like,but it seems clear we have a higher fraction of old manuscripts than biologistshave of the surely millions of members of species such as homo habilisor homo erectus. What's more, many of the creatures whose fossilshave survived died young, withoutoffspring, whereas the extant manuscripts may well have been copied.)But, with regard to manuscripts, weknow that every one was copied from some number of source manuscripts andcorrected from some number of others. We are guaranteed that splits occur,though we don't know when and at which point. The trick is to define thesplits. Just as species did not instantly convert from one form to another,you probably can't say that a particular manuscript is of some type anda copy of it is of some other type. And, just as some species are closerto each other than others, so may one text-type be closer to another.

Dawkins, in fact, has a warning from biology about this, which surelyapplies in textual criticism as well: "Members of the cladistic schoolof taxonomists can become positively evangelical... [in] proclaiming thenon-specialiness of fossils.... They take the sensible statement, 'It isunlikely that any particular fossil is the ancestor of any survivingspecies,' and interpret it to mean, 'There never were any ancestors!'Obviously this book stops short of such an absurdity. At every single momentof history there must have been at least one human ancestor... even if anyparticular fossil almost certainly isn't it." Similarly, in textualterms, every manuscript traces back to the autograph through similar manuscripts,even if those manuscripts haven't survived. L in the gospels probably is notdescended directly from B, and B is probably not descended from P75,but L certainly has an ancestor written about the same time as B which wasmuch like B, and B has an ancestor that was much like P75. Manuscriptswith similar texts will have links at least somewhat more recent than theautograph.

Colwell once said that "Weak members ofa Text-type may contain no more of the total content of a text-type thanstrong members of some other text-type may contain" (Studies inMethodology, page 33). This entirely fits what we learn from evolution.If I read Dawkins correctly, for instance, it appears that rabbits and micesplit before humans and lemurs. Yet, based on the external characteristicsat least, it appears that rabbits and mice are more similar than humansand lemurs. Humans and lemurs are more closely akin in terms of branching --but the level of evolution along the primate branches has been extreme, whereasthe rodents and lagomorphs (rabbits) have evolved more by specialization thanby creation of new characteristics.

In this context, we note that degree of evolution is not thesame as degree of kinship. Dawkins, (The Ancestor's Tale, p. 323),prints an evolutionary tree (phylogram) showing degrees of evolutionary divergencefrom the ancestor. I'm going to print a very simplified (and probably not veryaccurate) version of this as a demonstration. The longer a particular line, themore change in the creatures since the branching point.

         |------------------- human       |-|       | |---------------- blue whale     |-|      | | |------------------ opossum     | |-|     |   |-------------------------- platypus     |     |   |------- birds     |   |  |--|---|------ turtles and skinks  |  |   |  |  |   |---------- alligators|-|  || |  |----------------- amphibians| || |------------- lungfish||     |--- trout and salmon| |---|| |   |---------- cod|-|  |  |------ carp and loach

Note what this says: Although mammals such as humans and whales have undergonea much higher rate of evolution than trout or cod or carp, we are notdescended from trout or cod or carp -- indeed, we are less related to themthan to the surviving lungfish, even though lungfish are still pretty much fishand we are, well, us. All of the species involved have changed. It's just thatwe've changed more obviously. But we're all equally separated from the commonancestor. (Indeed, the fish are probably more separate in terms ofgenerations; a fish generation is typically one year or less, whereas a hominidgeneration is many years.) Then there is the platypus: It's usually regarded as"primitive," and certainly it has primitive features such as laying eggsand secreting milk through the skin rather than having distinct nipples. But thisdoesn't mean it hasn't evolved. To survive with these primitive features, it hasin fact evolved very heavily, developing (for instance) an electrical sense in itsbill that allows it to detect small prey with its eyes closed. To get from the earliestmammals to human beings involves few "inventions" (we have a big brain, andhands -- but all mammals at least have some brains, and forelimbs). To get fromearly mammals to a platypus involves a new invention: That electrical beak. Todevelop that requires a lot of genetic change.

This again goes back to Colwell's point: Just as we aremore related to birds than to cod, even though the differences between humans andbirds are in many ways more dramatic than the differences between humans and fish,so the variations within an early text-type may seem nearly as dramaticas the differences between an early and a late text-type.

There is an interesting side point here, not experimentally verified butwith some good mathematics about it, based on the work of E. Mayr. Mayrexamined the process of speciation -- what happens when one species becomestwo. It is widely believed that this usually happens because of some"separation event." A "separation event" comes about whensome outside factor causes a population to split in two -- an example mightbe a river changing its course and dividing what, until then, had beena local population of some sort of mice, say, which cannot swim across theriver.

As long as the members of the species could interbreed, it was hard toseparate into two species, because everybody could breed with everybodyelse. New genes would tend to be swamped.

Divide the species in two, and there is no longer any interbreeding.The two halves will start to evolve separately, and so may more easily becomeseparate species. This is not certain, note, but the separation makes it easier.

Thus far is generally agreed. Mayr's work comes in looking at the two populations.The conclusion is that the smaller population is more likely to change dramatically.This is simple mathematics: If a small mutation occurs, it is much more likely tosurvive in a small gene pool where it is less likely to be overwhelmed. The smallerthe population, the faster new genes can spread -- plus it's quite possible that asmaller group will be subjected to more selection pressure.

When I read about this, I instantly thought of the local texts idea and theirevolution. If you have a lot of manuscripts, change will be slow: There are alwaysmany manuscripts around to cross-check against. If a manuscript contains an error, itcan be compared against another and corrected.

Now imagine a manuscript in an isolated monastery or some such place, with fewother manuscripts to compare against. Perhaps they started with only one (or perhapsone of each section, or only one of the Apocalypse), andit not well copied. Having no other manuscript to be compared against, its errorswill either survive or be fixed by conjectural emendation. As copies are made,additional errors will creep in. And, if the original was a papyrus manuscript,it will likely wear out in short order and no longer be available for comparison.Where there are fewer manuscripts, there may well be more diversity.

Now consider the Byzantine text: It is the most common text-type, and veryunified. The Alexandrian text is smaller and less unified. The "Western"text is smaller still and even more diverse -- so diverse that we can't evenagree on its boundaries. Is it a wild text -- or was it simply never widelycopied? Mayr's theory implies it might be either.

A small population isn't the only thing that can cause wild modificationsof a species, to be sure. Darwin, it should be noted, proposed not one buttwo methods of evolution. This follows from the fact that evolutionarysuccess requires an animal to do two things: It must survive -- and it mustreproduce. Survival is the province of natural selection, which is the best-knownpart of Darwin's theory. But reproduction is the province of "sexualselection." Sexual selection operates when one sex (usually females)has a choice of members of the other sex (usually males), and chooses forreasons not directly related to survival. Examples of this include femaleswallows which prefer males with longer tails (when experimenters randomlylengthened or shortened the tails of certain swallows, it caused thelong-tailed males to have more children and the poor guys with the shorttails to be discriminated against) and many species of fish, where thefemales prefer certain colours (experimenters increased some males'reproductive success by painting them red).

What is interesting about sexual selection is that it can lead to arapid "runaway" effect. Take the swallows: Because femalesprefer long-tailed males, they breed with them, and genes for short tailsdie out very quickly. So now you have a population in which the averagetail size has increased. Are the females satisfied? No, they now have aneven longer-tailed set of males to choose from, and will still go for thelongest tails. So a tail which, some generations ago, would have seemedvery long suddenly seems rather shrimpy. The population develops longerand longer tails until such time as natural selection kicks in and makesthe cost of a longer tail so high that it starts killing off males whichhave one of these uber-tails. This is what is thought to have happenedwith peacocks, for instance. Peahens went for the males with the big fancytails, so the tails eventually became really extreme -- so extreme that,if they got much bigger, the peacock simply couldn't survive.

(It is sometimes objected that this process won't work, because thereare females who prefer short tails and mate with short-tailed males andpreserve the genetic diversity of the species. This turns out not to betrue. There are two possibilities. Either the females who don't care aboutlong tails are in fact attracted to short tails, or they are indifferent.If it is the former, then you'll always have short-tailed males matingwith short-tail-loving females, and you get two runaway processeswhich result in the creation of two species, one short-tailed and onelong-tailed. In the case where some of the females prefer long tailsand some are indifferent, long tails will still come to dominate, becausethe long-tail-loving females will mate with long-tailed males -- and so willa lot of the females who don't care about tail length, because they don'tcare. So more and more males in each generation will have long tails, andthe long tails will eventually dominate. The "runaway" effect isalmost uncontrollable once there is a significant preference for an arbitrary"fashion.")

It is possible that an analogous process explains some of the characteristicsof text-types -- the alleged abruptness of the Alexandrian text or the smoothfeel of the Byzantine text. Suppose a particular bishop, or even a handful ofscribes, decided that the best texts were full and smooth. They would choosethe fullest available manuscripts to copy. If a particular passage twice read"the Lord Jesus Christ" and once read simply "the Lord Jesus,"they might well modify the third instance to match the other two. Over time,they would tend to produce fuller and fuller texts. They would prefer the riskof including a few non-canonical words to the risk of excluding a few canonicalwords.

But another scribal school, determined to have no word that was not scripturaleven if it meant omitting a few canonical words, chooses short texts, omitsarticles and Christological titles when they are lacking in parallel passages,and so forth.

Alternately, just consider a manuscript which has some marginal comments --say, where the text reads "Jesus," the margin says "This shouldbe 'the Lord Jesus,'" and the next time the text reads "Jesus,"the margin read "This should be 'the Lord Jesus' also." The next timethe scribe reads "Jesus" in the text, the tendency might be to correct"the Lord Jesus," and a runaway process gets started.

Note that each of these processes will be self-perpetuating as long as thesame scribal principles apply. Thus you get an excessively full Byzantine textand an excessively short manuscript like P75. And just as we haverunaway readings, we also get what we might call runaway editors -- people likeWestcott and Hort, who tend to prefer the shorter reading no matter what, andthe Byzantine prioritists, whose rule comes close to being "prefer thelonger reading." (The problem is, of course, that in a biological"runaway" there is no issue of what is right or wrong or original.Editors are supposed to worry about that, but can suffer from a runaway lovefor a particular canon of criticism....)

There is another rule of evolution which perhaps also applies here -- therule of "local maxima". Daniel Dennett, in Darwin's Dangerous Idea (1995), p.190, states this as "never step down; step up whenever possible." That is, whenon a "fitness landscape," evolution will always favor the form which is more fitin its immediate context -- even if there is an even more fit form at a slightlygreater distance. Evolution tends to "get stuck" on local peaks. Compare a text:At any given point, it will tend to adopt the "more reasonable" local reading evenif it produces problems overall. (Another name for this is the QWERTY effect,so-called because we still use QWERTY keyboards even though they are not veryefficient. It's a fossil format we can't get rid of, because we're too used toit. There are better keyboards -- DVORAK, for instance -- but to get there, we wouldall have to un-learn QWERTY and be, for a time, completely keyboard-incompetent.In evolution, it can't happen; in keyboards, it can only happen if we decide to handall our kids DVORAK keyboards.)

This also brings up the constant question of "lumping" or"splitting." These have now become rather standard terms, with"lumpers" being biologists who place similar but not identicalspecimens in a single species, while "splitters" divide anythingnot shown to be identical. This can get pretty strange even for existingspecies -- in my lifetime, two types of birds, the Baltimore and Bullock'sOrioles, initially listed as separate species, were lumpedinto one species, the "Northern Oriole," then split back intoseparate species again. And these are living creatures where we can observetheir breeding habits! In the case of fossils, splitting can become soextreme that just about everything becomes its own species.

And species is the one definable term in biology. Splitting or lumpinga family or phylum is certainly more arbitrary. Similarly, splitting orlumping text-types has to be arbitrary. The obvious defining point wouldbe the last common ancestor -- but without having that common ancestor in hand,we don't have much to go on, we are forced to try to reconstruct. And that'swith even if we ignore mixture.

The splitting/lumping issue is a significant problem. Suppose that theByzantine prioritists areright and the Kx group of manuscripts in fact represents the originaltext. In that case, the Family Π group of manuscripts probably couldbe considered a separate text-type. But if the Byzantine type is not original,then the Π manuscripts are at best a sub-text-type.

This reinforces a point made above with regard to text-types.Evolutionary phyla do not have tobe equidistant from each other. Some are closer than others. There hasto be some level of difference, but there can be more than the minimum -- andthe minimum can be relatively small. Rigid definitions are a mixed blessing:They allow us to speak precisely, but they must not be allowed to bind. Newdata must allow us to change our definitions, just as biologists havechanged the genus and family classifications of many species over the years, andas astronomers recently (and quite correctly) downgraded Pluto from a planet toa dwarf planet. (They did so correctly because there is a difference in kindbetween Pluto and the other planets: Pluto is a typical Kuiper Belt object; thereare lots of things in the same general area much like it. There is nothing likeJupiter in Jupiter's orbit.)The comparison to the Colwell-Tune 70% criterion for differentiatingtext-types should be obvious: The 70% difference plus gap was for theAlexandrian and Byzantine texts. There is no particular evidence that itapplies to anything else. It's just as if you said that, because mammalsand reptiles differ in 47 particulars (or whatever number you produce),then reptiles and birds must differ in exactly 47 or they can't be separategroupings.

This problem even infects the mathematical models of biological stemma.This is known as "long branch assimilation." If two particularspecies diverge far from the main bulk of specimens, parsimony analysiscan pull them together. (Genetic trees with branches of this type are saidto fall within the "Felsenstein Zone.") This certainly remindsme of the Claremont Profile Method and itsinfamous lumping of Codex Bezae with the Alexandrian Text. Keeping in mindalso Colwell's warning that strong members of distinct text-type may sharemore readings than strong and weak members of the same type, might there notbe other unnoticed examples of the same thing? (For a slightly artificialexample of how this might actually come about with a text, see the appendixon The Bédier Problem in thearticle on Non-Biblical Criticism).

The key point here is how we use text-types. If they have anyuse at all, it is to supply relatively independent paths back to thearchetype. This obviously argues strongly for the "ancestral"model of a text-type rather than the statistical model used by followersof the Colwell-Tune definition.

One place where genetics has curious traits is with regard to mixture. Generallywhen a lineage splits, that's it -- there can be no recombination. Dawkins inThe Blind Watchmaker, p. 248, notes for instance that humans have eightdistinct genes for making globins (hæmoglobin, etc.) These genes are allbelieved to be descended from a single original globin gene, even though they nowexist on separate chromosomes. Because they are separate genes, in separate places,they can no longer mix; we can create a stemma and perhaps recreate the originalglobin. But if we did, it couldn't be used for anything; the current globins are nowseparate and individual. At least in theory. It's largely true in practice, too,for animals, since they only mate with their own kind. It's a lot more complicatedwith plants, where foreign pollen can sometimes show up. I have, frankly, no ideahow this affects things; it might be worthwhile to find out.

While we're talking species, and text-types, and mixture, we might alsomention the curious phenomenon of "ring species." This is an unusualphenomenon because it requires a sort of habitat loop -- a region ofterritory where animals can live at the boundary but cannot cross the middle.An example is the shores of a very large lake (either in or out of the water),or a particular elevation in a valley surrounded on all sides by mountains. Dawkins(The Ancestor's Tale, p. 301) offers the example of California's CentralValley and the Ensatina salamanders. These salamanders live only ata certain elevation. Since the valley is entirely enclosed, their habitat lookslike a very elongated letter "O," about four times as tall as it iswide, with a very large region in the middle where the salamanders cannotlive. If you start in the southwest corner of the loop, you'll find salamanderswith plain skins. Move north along the western side of the valley, and you'llgradually see slight blotches appear on their skins. Once you reach the northend, turn south, and travel along the east side of the valley, you'll findthat the salamanders'skins will get more and more blotchy; eventually, when you get to the southeastcorner of the ring, they are extremely blotchy.

Now here is the interesting point. Start at any point along the ring,except the southernmost part, and salamanders will breed with their neighbours to theclockwise and counterclockwise directions. There is no species distinction.But, down at the southern part, you have plain-skinned and blotchy-skinned salamanders,and they will not interbreed. In other words, there is a species distinction there,even though there is continuous variation around the circumference of the ring.(Anti-evolutionists claim we've never seen a new species created in the lab.The ring species, however, is a pretty good example of how it comes about. Ifa flood or earthquake or human activity were to destroy the northern end of theCentral Valley, this continuous species would suddenly become two species! Thuswe could do it if we wanted to.)

Ring species probably can come about in either of two ways. One is to have anintermediate species split in two (in the example above, a slightly blotchyspecies of salamander might have arrived at the northern part of the centralvalley and spread in two different directions); the other is to start with onedistinct type and have it slowly crawl "around the circle" (in theabove case, the ancestor was either a very plain salamander in the southwestor a very blotchy one in the southeast, which bred only one way around thecircle). Could textual "mixture" also arise by both means? That is,could one "mixed" manuscript be the ancestor of two distinct typesof text (a common original splitting in two because of genetic drift), whileanother derives from combining two types of text (a hybrid)? There is no logicalreason why not. The implications, however, are very different. In the formercase of a split, both types have value (since they lead back to an earlier archetype), andtheir agreements have particularly high value. In the case of the hybrid, though,the hybrid text has no value unless the ancestral texts are lost. (This is, ofcourse, precisely what Hort said about the Byzantine text, and why he denigratedit. And no one hasseriously contested the logic; the question is whether his history of the textis accurate.)

The example above also points up the generally-agreed cause of separation intospecies: Sudden (usually unexpected) geographical separation. If a lake is splitin two by an earthquake, say, fish in the two halves, originally one species, mayevolve into two. Indeed, Dawkins (The Ancestor's Tale, p. 341)observes that, for some fish species,a gap of just two kilometers between reefs in a lake is enough to cause geneticseparation. Is this not much the same as the proposed origin oflocal texts, where a particular regiongradually standardizes on a peculiar text?

Evolution may also say something about the nature of variants. You've probablyheard that most creatures' DNA is rather a jumble of stuff. It isn't as if someoneset it up in an intelligent, orderly manner; it's scattered all over the place onthe chromosomes. (Just about what you would expect of stuff that has evolved andchanged and developed new purposes over the years.) Much of it, in fact, no longerhas any purpose at all, and is not used. (This might, for instance, include DNAfor making gills in humans: we don't live underwater any more, so we don't need gills --and even if we had them, as warm-blooded creatures we can't derive enough oxygenfrom sea water to meet our needs.) This is the so-called "junk DNA" --a name which accurately describes how useful it is, though a better historicalname might be "fossil" or "discarded" DNA.

The interesting thing is, this unexpressed DNA tends to change faster thanDNA that actually does something. This makes sense, when you think about it.If a gene needed to create, say, the human lung mutates, the probability is highthat the mutation will be detrimental -- quite possibly fatal. It will probablydie out. But a mutation that affects the no-longer-used genes that make gillsor whatever can be preserved, because the changes have no effect on the survivalof a human who doesn't use gills anyway.

(Junk DNA and its high rate of mutation, incidentally, has some significance aswe consider which variants are and are not genealogically meaningful; see thearticle on Saturation.)

This at least bears thinking about. There are only two significant many-verse variantsin the New Testament: Mark 16:9-20 and the story of the Adulteress. There aremore than that many add/omit article variants in the average chapter.You might argue that the latter is a meaningful variant -- but it isn't verymeaningful. In the case of a definite article before a name, it means almostnothing -- and these are incredibly common. (If you check the section onMost Uncertain Readings, examining just theGospel of John, we find two dozen variantsιησους/ο ιησους.That's not variants in one or two minor manuscripts, note; they are variants substantialenough to cause real differences between editors.)Could it be that minor variants will survivebetter than major? Of course, that needs to be tested -- but there are at leasta few manuscripts that seem to bear this out. A in the Gospels is mostly Byzantine --but it has a much higher number of major Alexandrian variants than lesserAlexandrian variants, as if its ancestor were a Byzantine manuscript looselycorrected against an Alexandrian manuscript, but with only the major differencesnoted.

There is a curious analogy to this in some a sexually reproducing species.Most species of rotifers reproduce sexually, the equivalent in a text of mixture.But there is a group that reproduces asexually -- no mixture, just direct copying.It seems pretty clear that they are descended from an ancestral species thatreproduced sexually, since their chromosomes still come in what superficiallyappear to be pairs (five pairs, ten chromosomes total).

Now here is the interesting point. These bdelloid rotifers are now regarded ashaving divided into 360 species. All derive from one ancestor and her tenchromosomes. All have undergone some mutation and evolution. But, because thechromosomes no longer mix and match, the chromosomes of each pair are freeto evolve away from one another. There is no longer a need for chromosome4-left to be interchangeable with 4-right. And indeed, they no longer are. Whatwere once five pairs of chromosomes are now, in effect, ten single chromosomes.

And it gets more interesting than that: Often the chromosomes display lessdifference between species than within species. That is, if you compare4-left in species A, it is more like 4-left in species B than it is like4-right in species A. Indeed, there may be more variation in 4-left withinspecies A than there is between A's 4-left and B's 4-left. Here theanalogy is perhaps to text-types; if we cannot know how much internal variationthere is within a species, does that not imply that we cannot know how muchinternal variation is in a text-type?

(As an aside: The survival of bdelloid rotifers is rather an evolutionaryscandal. Although there are a lot of asexual multicellular species, almost allare members of very small groups. Asexuality keeps coming up, but on the evidence,it also results in the species dying off, presumably because it can't adapt tonew conditions very well. But there are 360 species of bdelloid rotifers, andthey've been around for more than fifty million years. Clearly asexuality worksfor them. No one could figure out why -- but, according to a recent report onNational Public Radio's "Science Friday" program, we may at last havethe answer. In certain circumstances, bdelloids can borrow genes from otherspecies and attach them to the ends of their chromosomes. The evolutionaryadvantage of this is clear: They can bring in new genes, but also gain theadvantages of not being forced to bring in new genes. The dangers ofasexual reproduction are much like repeated copying a manuscript without evercorrecting it or comparing it against other manuscripts: Repeated errors willoccur, and each copy will be more remote from the original than the one before.Eventually you get a copy too corrupt to be usable. But if a copy is proofreadand any nonsense reading corrected, the decay will be slowed significantly. Itisn't as good as complete and regular corrections, but it may actually result insome good conjectures....)

A sidelight on this is provided by the human X and Y chromosomes, the onlyunpaired chromosomes in the genome. These chromosomes have developed what arecalled "sexually antagonistic genes." The X and Y chromosomes, beingdistinct, no longer need to share genes, and in fact can develop genes whichsuppress each others' actions. This, in fact, is pretty much what it means tobe male: A handful of genes on the Y chromosome have suppressed the process ofbecoming female. The fact of sexually antagonistic genes, in fact, is believedto be why the human Y chromosome is so small: In the population as a whole, it'soutnumbered 3:1 by the X chromosome, meaning that X can evolve much more quickly.So where the two conflict, Y is going to lose. As a result, it abandons the battle;there are few genes still in use on Y. Small as it is, it's mostly junk DNA.Most of the genes that used to be on Y are believed to have moved to otherchromosomes.

This antagonism can be extraordinarily real. This has been shown in fruitflies. The seminal fluid of the male has been shown to try to increase femaleovulation and suppress the sexual urge -- in other words, the male fly uses itssemen to try to make sure the female doesn't mate with anyone else. The femalegenes, naturally, want to keep their choices open, so they evolve immunity tothe chemicals in the semen.

At least, in nature they do. Matt Ridley, in Genome, pp. 113-114,describes an experiment undertaken by William Rice, in which a population ofmale flies were allowed to keep evolving more aggressive semen, while a populationof females was made to keep its old semen resistance genes. After 29 generations,Rice reunited the breeds -- and the male semen had grown so strong as to beirresistable, even fatal, to the unevolved females. (This, incidentally, shouldpretty well answer any questions about evolution not creating new species. Rice'sflies are already on the brink of speciation; another few dozen generations ofthat and the old and new flies functionally couldn't interbreed at all -- the malesmight try, but since the females would produce no eggs, the matings would beinfertile.)

This sort of thing probably can't happen in the Bible text, because mixturedoes not involve the same sort of antagonism. (Also, the Bible doesn't breed asfast. There is some mathematical work on how fast a population can be traced backto a common ancestor; Dawkins summarizes it on pages 42-45 of The Ancestor'sTale. It involves many assumptions, and we have to add more to apply it to thetext, but as a general model, it appears there are only about fifteengenerations between the manuscripts surviving today and their primary archetype,and only seven to ten between that archetype and the autograph. This isn't enoughgenerations to allow speciation except in the most extraordinary circumstances.)But it bears some thinking about.When text-types mix, which readings will tend to be perpetuated? Answer: It appears,in general, the longer ones; scribes didn't want to risk leaving out any wordsthat might be original. There are exceptions (424 being the obvious example). Butthey do appear to be the exceptions.

Note the implication: Because the Byzantine text is the longer, fuller text,its readings will tend to prevail at any stage of mixture. Does this meanthat this is how the Byzantine text came to prevail? No. What it does mean is that,all else being equal, the Byzantine text could be expected to prevail.

So much for "normal transmission." It applies, at best, only wherethere is no mixture.

Some footnotes. There seems to be a common belief that evolution has some sortof appointed end (typically us). This is an extreme and dangerous misconception.Evolution always operatesafter the fact: First variations arise in the population, then natural selection acts onthem. To give an analogy: Suppose you're on the way somewhere (say a shopping mall)and you come to a branch in the road. From there, there are two ways to get to the mall,depending on whether you take the left or right fork. Once you take the a particularfork, your route is pretty well determined. But until you make that decision, it'sentirely up in the air.

Similarly, many evolutionary problems have multiple solutions. As an example,consider the disease rickets, caused by an inadequate supply of Vitamin D. This wasnot a problem for the dark-skinned early humans, who lived in Africa; they didn'tneed to cover their skin for warmth very often, and they got full sunlight all yearlong.

Take someone like that to Scandinavia and he or she might well die of vitaminD deficiency. (Or so I heard many years ago; I don't know if this analysis hasheld up in the days of DNA analysis. In any case, the analogy is correct.)

There are several possible solutions to this problem. The body could evolve tomanufacture vitamin D some other way. Or it could discover some alternate source(this is what the Inuit did, for instance -- they get their vitamins from the organmeat of seals, and remain relatively dark-skinned).Or -- Scandinavians could develop light skin, allowing sunlight to create VitaminD more easily. All three of these techniques are equally valid (at least forthe vitamin D problem). But Europeans ended up with #3, while the Inuit use #2.

Evolution is always like that. It does not necessarily find the bestsolution to a problem; it finds better solutions than what went before.A species suffering too much predation may learn to run faster, or develop bettercamouflage -- or it might just start breeding faster to keep the population up.Do this long enough, and you might get a very superior creature of some sort --but it can take a very long time, and the outcome can be quite unexpected. Indeed,it can be a very poor adaption for any circumstances but its own; this iswhy it was so easy to drive so many species, such as dodos, extinct. An exampleof an adaption that works only in its peculiar context is the cave fish that havelost their eyes: In pitch darkness, eyes don't help and leave them with a vulnerablespot. Occasionally, of course, such fish get washed out of the cave and intodaylight, where they find themselves at a huge disadvantage. That being the case,the best solution for the cave fish would not have been to lose their eyes but todevelop some sort of very strong eyelid to protect it. But, for the fish stillin the cave, this solution is no better than losing their sight, and probably harderto develop. So the fish go blind because it's a workable answer to a genuine problem.Such "quick fixes" are found in the human genome, too: we've alreadymentioned the sickle cell mutation. This seems to have been quick-fix human answerto malaria, which became more common when human clear-cut land, making morebreeding sites available for malaria mosquitoes. A better solution would havebeen to develop real immunity to malaria, but sickle cell was better than nothing,and it was an easy mutation to create. Similarly, the cystic fibrosis gene iseffectively fatal to people who have two copies -- but people with one copyseem to be nearly immune to typhoid (see Kevin Davis, Cracking the Genome,p. 47). So that gene, which is as dreadful as the sickle cell gene, iscommon in Europe.

This is perhaps a useful warning for the textual critics who have tried toreduce scribes to automata. A scribe confronted with what appears to be an errormay try to fix it -- but you probably can't predict the fix. If it's a "good"fix (according to whatever definition of "good" other scribes use),it may well propagate. But you can't predict the fix before it's made.

Another interesting point about evolution is the modern concept of"punctuated equilibrium." Evolution is not continuous -- when conditionsare stable, evolution operates very slowly, with few changes over the years.Upset the stable conditions -- due to climate change, or the arrival of a newspecies from outside, or just a wildly successful mutation -- and the wholething has to, in effect, scramble to find a new equilibrium. These are theconditions under which species more rapidly go extinct and new species are created.

Now think, for instance, of the various persecutions of Christianity.Emperors such as Diocletian destroyed every Bible they could get their handson, and took out a certain number of scribes as well. This means that there islittle opportunity to compare manuscripts, and many of them will be copiedsecretly and by amateur scribes. This will probably encourage "mutations" --new variants and text-types evolving. We can't see this happen very much (thepersecutions and later barbarian invasions took place at a time when the manuscriptrecord is very thin), but it seems reasonable that this might happen.

While we're looking at history, let's take one note from another evolutionaryprocess: That of language. We mentioned above the Proto-Indo-European languagethat is the ancestor of (among others) English, German, Latin, and Greek. Since wehave a stemma of sorts for this language's descendants, we can reconstruct most ofthe language (basically by taking the grammar of Sanskrit and reconstructing thevocabulary by stemmatic principles). This reveals interesting points. For example,the reconstructed language has a number of words pertaining to agriculture. Thisimplies that it originated after agriculture had spread to their regions. (It hasbeen hypothesized that the success of the Indo-Europeans was due to their possessionof agriculture). Certain other words -- e.g. relating to pastoralism and to metals --are not found, implying that it predates the introduction of those habits.

This sort of conclusion based on linguistic data is pretty fragile, especiallyas regards the argument from silence. (It's theoretically possible, e.g., thatthe Indo-Europeans herded, say, gerbils, but because none of the societiesdescended from them did gerbil-herding, all relevant words died out and werereinvented later.) But sometimes they can be important. There are occasionalanalogies to histories of texts. I can't think of a good one for the New Testament,but consider Isaiah 7:14. If a version translated from the Hebrew says that ayoung woman shall bear a son (which is, of course, the correct readingof Isaiah), it tells us very little. But if a versiontranslated from the Hebrew says that at virgin shall bear said son -- amisrendering which originated with the Septuagint -- there is probably Christian influence in there somewhere. Or at least LXXinfluence.

One key aspect of evolution has little relevance to Biblical texts: The so-called"arms race." This is what comes about when two species are in particularlyclose competition -- say an herbivore and a predator, where the predator is theprimary killer of the herbivore and the herbivore is the predator's primary food.Call them, for the sake of simplicity, antelope and leopard. They can't escapeeach other (barring a habitat change or the intervention of another species). Ifantelope start running faster, then leopards will get faster in response. Ifantelope learn to hide more effectively (by disguising their appearance orscent), then leopards will develop better eyes or ears. If antelope start to breedfaster, then more leopards will be able to survive to consume the largerpopulation. No matter what one species does, the other will find an answer (orgo extinct). As the years pass, they have to devote more and more energy toleg muscles, or to fancy fur patterns, or extra offspring, or whatever it takesto survive. If there were a way to call the whole thing off -- for the antelopejust to give in and say, "Here. Take ten percent of us each year (or whateverpercent the leopards actually take) and stop evolving," it would make lifeeasier for both species. But they can't; they're stuck. Ultimately, this is verylike the mathematical problem known as the "prisoner's dilemma" (seethe article on Game Theory).

This, as noted, does not occur in textual criticism -- though it does sometimesseem to occur in denominations, as preachers desperate to build congregarions threatenworse and worse hellfire. I do sometimes wonder about a sort of a race betweenplain-text manuscripts and lectionaries -- since lectionaries were more useful inchurches, there would be pressure on plain-text manuscripts to become more and moreuseful for church reading, so that lectionary incipits and such would be put intothe margin -- and even into the text (as happened, e.g., with1799). I doubt this hasaffected manuscripts seriously -- though it's had some pretty strange effects onEnglish translations. (I have a New Revised Standard Version with a marginaliadesigned, I think, for a King James Version by a very conservative scholar. At times,it seems as if text and margin are at war; at others, the marginalia, by adding sectionheadings and such, appear to me to at least distort the meaning of the text by dividingsections which should be united.)

Finally, a word about evolutionary progress versus evolutionary directionversus randomness. I've repeated several times above that evolution does not resultin progress -- that, e.g., a mole is not "better" than, say, a weasel, atleast in the general sense of surviving; they're just different. There is a tendencyto think that, if a process doesn't have a destination, it must be random. This is not atall true. Evolution doesn't have a destination, but it is rarely random. Dawkins, inThe Blind Watchmaker (starting around page 65), points out the difference betweenrandom selection and cumulative selection. This is a very important point.Random selection, in which you simply throw a bunch of traits together, has no directionand would almost never produce improvement. Cumulative selection is altogether different.

Let's take a very simple test (Dawkins does something like this, but I'm going toproduce a variation which I think makes it clearer). Let's produce 10-digit stringsof numbers, consisting of the digits 1-3. Call each 10-digit sequence a"creature." So 1111111111 is a creature, and1231231231 is a creature. It can be shown that there are 59049 different creaturesof this type.

Now here is our goal: We want to create a creature that has all digits belongingto one set. We don't care which set; just all belonging to the same set.

Remember that there are 59049 creatures. There are only three of them which meetour criteria: 1111111111, 2222222222, and 3333333333. So if you just set up a randomcreature generator and have it spit out creatures, only one creature in 19683(59049 divided by three) will be of this type.

To demonstrate this point, let's try 25 generations of random selections. Mytrusty spreadsheet gave me this list:


Not one of them is acceptable -- in face, only eight of them have even the first twodigits the same!

That's random selection. Chance never gets us anywhere. If by some coincidenceyou get something close to an acceptable form -- well, it will all be jumbled in thenext generation, so even being 90% right is no good. Under random selection, youhave to have everything right the first time. Some people claim that this isso improbable that evolution can't work. And they may well be right -- except thatrandom selection isn't how evolution operates.

Keep the problem of random selection in mind as we consider cumulative selection.Here's how cumulative selection works:Once you find a partial solution, you refine it and converge toward a better form of it.For example, take our first creature above:3232232231. It has, by chance (or, perhaps, by defect of Apple Computer's built-inrandom number generator), only one case of 1, five of 2, and four of 3. So this creature"inclines toward" 2.

So our goal is to "evolve it" toward 2. Note that the choice of 2 isentirely arbitrary. If there had been more instances of 1 than of 2, we'd say ourcreature inclined toward 1, and evolve that way. But this one inclines toward 2. Sowhat we do is, we hold every instance of 2 to be fixed, and let only the otherdigits evolve. How long does it take to get from 3232232231 to 2222222222?

Answer: In my first run, it took all of three generation:


Remember, in random selection, it would almost certainly have takenthousands of generations.

Of course, this is extreme. We started with a number that was very two-heavy. Let'stry this a few more times. Remember that we will select for whatever is the mostcommon number in our first try. Here are the results of six more tries:

8 generations

5 generations

8 generations

8 generations

8 generations

3 generations

This shows the absolutely astonishing power of cumulative natural selection. We haveachieved our result about a thousand times faster than randomly assembling traits. Andif we were trying to achieve something like a living being, with an even lower randomprobability, the advantage of cumulative selection would be even greater. (There appearsto be a logarithmic relationship here, though I haven't seen math on this and am too lazyto work it out. Suffice it to say that cumulative selection produces a huge improvementin evolutionary speed.)

The example above may sound improbable -- shouldn't there be a best way for aspecies to survive? This is an easy fallacy for humans to fall into, because we areby far the smartest, most tool-making, fastest-spreading species on the planet. Sowe have a tendency to think that we (or at least our key trait, which is intelligence)is the purpose of evolution. By no means. As we've noted several times, many survival problemshave multiple solutions (e.g. better concealment, better eyesight to spot predatorssooner, higher speed to outrun predators, or faster reproduction to have offspringbefore the predator can kill you). Sometimes the different "cures"can be just about very similar in style and nearly equal in effectiveness.Let's try one more example -- consider an arbitrary species of flowers(call them rolys -- sort of half way between a rose and a lily)and pollinators. It happens that bees cannot see the colorred, so they will not pollinate red flowers. Hummingbirds, as a result, are speciallyattracted to red flowers, and pollinate them; if there are enough red flowers, theymay ignore something with petals of another colour.

Now suppose a species pf rolys shows up where some of the flowers are red andsome are blue. The red ones will be pollinated by hummingbirds, the blue by bees. Ared flower, as a result, will never be pollinated by blue pollen, and and blue flowerwill never get red pollen. There are onlytwo possible outcomes: Either cumulative selection will apply, and one or the othercolor will come to dominate (presumably red flowers if hummingbirds are more common,or blue if bees are the primary pollinator) -- or the species will split into two, withred rolys and blue rolys not interbreeding and eventually becoming separate species.

This could perfectly easily happen to literary events, too. One that occurs to meis the reporting of miracles. Christianity regards miracles as validating its truth.As a result, we see non-miraculous events treated as miracles (see, e.g., the story ofEutychus in Acts 20:9-12. Paul didn't do anything; he didn't heal the boy, andfor all we know, Eutychus died later or was permanently crippled. But it's given the feelingof a miracle. Or consider Elisha and the Shunammite's son. 2 Kings 4:34 describeswhat sounds like mouth-to-mouth resuscitation -- but, again, it's treated as amiracle).

Islamic tradition is the reverse: Mohammed denied that he was a miracle-worker.I can't recall a single human-worked miracle in the Quran -- not that I'm expert.But I consulted the translation of Abdullah Yusuf Ali, which is carefully indexed.It led me to Surah 29:50, which notes the lack of miracles; "The Signs areindeed with God [and not human beings]." The rather indignant footnote complainsabout unbelievers asking for signs (beyond the what are regarded as the self-evidentsigns of the existence of the universe, life, and such): "Everything is possiblefor God, but God is not going to humor the follies of men or listen to theirdisingenuous demands. He has sent an Apostle to explain His Signs clearly, and towarn them of the consequences of rejection. Is it not enough?"

You don't have to believe in Christianity or Islam to see how extremely divergentthese positions are! Clearly, if a slightly strange event happens, Christian folklorewill tend to turn it into a miracle; Islamic folklore will have no such tendency.

Now forget folklore, and miracles, and think texts. Start with the sameoriginal text, then hand it to an orthodox Christian, an Arian (who considered the Sonto be inferior to the Father), and a Nestorian or other monophysite who believed thatJesus was God and not man, or man and not God, or a figment of the imagination, orsomething like that. Without deliberate alteration, each scribe will probably make errorsthat support his theology. The resulting text will clearly be Orthodox, or Arian,or Monophysite -- and will encourage its copying by other scribes with that theologicaltendency, making the second generation even more partisan, and so on. It's very muchlike the cumulative selection case. Once the process starts, it will tend to proceedin the same direction because it's self-reinforcing.

Are there other lessons to be learned from evolutionary biology? Possibly. Forexample, we may need to rethink our canons of criticism. The canon "Prefer themiddle reading" is so obscure that most manuals don't even mention it. And yet,it is fundamental to evolutionary biology: Where there are three patternsof, say, mitochondrial DNA, and where A and B differ by one base pair, and B andC differ by one base pair, but A and C differ by two base pairs, the general assumptionis that B is the ancestral sequence and A and C are offspring. That is, B is the middlereading. (See Bryan Sykes, The Seven Daughters of Eve, p. 139.) If we say thatany stemma must allow only one change per "generation" of genealogy, thenwe have only three possible stemma. This rule says that the preferredgenealogy is:

    B                         A                    C  /  \                        |                    | /    \           NOT         B        AND NOT     BA      C                      |                    |                              C                    A

Appendix I: Genetics

Much of what has been said above is about evolution. I want to repeat somethingI mentioned above: Evolution today is not your parent's evolution, nor Darwin's.We are living in the era of genetic Darwinism -- neo-Darwinism.

By that I mean that the modern understanding of DNA has completely changed thefield. To see why, we probably need to say a few words about genes and genetics.I won't burden you with much history. Suffice it to say that, by the mid-twentiethcentury, it was clear that most of the chemical work in the cells was done by enzymes,and enzymes were made of proteins, and that the data needed to assemble thoseproteins was stored in DNA -- deoxyribonucleic acid.DNA structure: NucleotidesDespite the name, DNA is not asingle molecule, but rather an infinite class of molecules, built from five smallermolecular components which in turn combine into four basic pieces of DNA. The fivemolecules are of two types. Four -- the "nucleotides" --are used to store information, while the fifthprovides the framework in which the other four are stored. The fourpieces can be thought of a T-shaped elements which assemble like a puzzle. The cross barof the T is a phosphorus-based "backbone" (this, incidentally, explainswhy phosphorus spills at sea cause algae blooms: Phosphorus, since it is part of DNA,is absolutely essential to all life -- and phosphorus is present in a much lowerproportion in sea water than in living creatures. The limiting factor on an ecosystem,especially a water ecosystem, is almost always phosphorus. Add phosphorus and youget a population explosion lasting until something else becomes the limiting factor.Life is "accustomed" to phosphorus shortages; it is not "accustomed"to phosphorus abundance, and goes out of control if the supply is large enough.)

The stem of the T is where the real information is stored -- in an elaboratehexagonal or hexagonal-plus-pentagonal structure . These structures consist of one ofthe four nucleotides. The four are usually referred to by initials, A, C,G, and T; they are properly called adenine, cytosine, guanine, and thymine. (InRNA, which is a parallel to DNA with a somewhat different backbone, U=uracilreplaces thymine. Chemists refer to adenine and guanine as purines,cytosine and thymine as pyrmadines.)

The result really is like a children's toy. There is the rigid brace of thephospate backbone, the structure of the nucleotide coming off of it, and a coupleof spots where hydrogen bonds can hook, like the joins of tinker toys or theraised bumps on Lego blocks.

Note how beautifully functional all this is: Two of the nucleotides, A and G,are wide, with a double ring; the other two, C and T, are smaller. This meansthat the two possible links, A+T and C+G, are the same width. The one majordifference is that the A/T linkage, which has three hydrogen bonds, is slightlystronger (and in fact is slightly more common in DNA; it has been speculatedthat this is so the DNA itself is more firmly held together).

That clever linkage, in which the A+T and C+G assemblies are the samesize, means that DNA can form the famous "double helix," Ifwe untwist a strand of DNA into a sort of ladder, it might look something like this:

Untwisted DNA

Normally, of course, this is twisted around itself -- hence the "doublehelix" description (actually only a single helix, merely one with a twistedladder-like form rather than a straight strand, but let's not worry about that).

Since there are four and only four possible nucleotides as we read alongthe DNA strand, it will be evident that this is a digital code, done in base four.

Well, theoretically base four. In fact, like Hebrew, "words" are groupedin blocks of three letters. That means there are 64 possible "words."

In a curious feature of the code, which has its advantages and disadvantages, allof these 64 words have meanings, even though there the number of messages is smallerthan 64. That is, thereare only so many messages a word has to convey. Possible meanings are one of thetwenty amino acids used to make proteins, plus a few control commands (e.g. thereneeds to be something to say "stop" or "this is the end of theprotein.") So the sequence AAA might stand for the amino acid alanine,AAC for argenine, AAG for asparagine, etc., Once you have finished those 20+commands, the other 40+ possible sequences could be left as blanks, with nomeaning at all.

It doesn't work that way. Every one of the 64 possible words stands forsomething, meaning that there are about three ways to encode for eachof the standard commands. (In fact some amino acids are represented by as manyas six different codes, others by just one.)

One noteworthy element of the system is that all creatures tested usethe same DNA code. This is, in one sense, astonishing -- one DNA codeis as good as any other in terms of information storage. So if all species wereindependently created, they would be expected to use different codes. But oncea code is established, it's effectively impossible to change it; the result ischaos. So the fact that all known creatures use the same code stronglyimplies common origin.

The obvious disadvantage of the all-codes-have-meaning system is that it makesit hard to detect damage -- if we had only 21 codes (say, arbitrarily, AAAthrough CCA, or perhaps some other scheme where the codes are spreadthroughout the alphabet), then if AAA mutated into GAA, we could be surethere was a mutation and set about trying to fix it. (Francis Crick, theco-discoverer of the double helix, in fact proposed an encoding schemewith a very strong error-correcting element in it: it made it impossibleto misread DNA.Unfortunately, the language of DNA is not intelligently designed, anddoesn't follow Crick's encoding pattern.) The side effect of thissystem with no error correcting is that a lot of genetic diseases can cropup by random mutation at a single nucleotide -- as Queen Victoria of Englandapparently suffered a mutation which gave her one gene for hemophilia.She herself, having a good gene to cover for it, did not suffer hemophilia.But many of her descendants did -- including, famously, the son of Nicolas IIof Russia, with truly disastrous consequences.

The other side of the coin is, this system does make mutations easier.Most mutations are deleterious, as in Queen Victoria's case -- but someare advantageous. Apparently bad mutations are not too high a price topay, as long as there are occasional good mutations, too. (This actuallymakes some sense: Most individuals in most species don't live long enoughto breed, so losing a few sick individuals to bad mutations costs little,while even a few advantageous mutations can have a high payoff. It is, byordinary standards, very cruel -- but it makes sense, evolutionarily.)

But this makes geneticists practice a discipline almost like textualcritics. DNA is a series of words -- words which are all the same length,and with a total vocabulary of only 64 words, but they are words. Andthey form sentences -- complete genes, which encode complete proteins.And the sentences, unlike the words, can be almost infinitely long andcomplex.

Consider the implications. Suppose we compare the genes for making, say,hair in five different species. I'm just making this up to demonstrate thepoint, but the principle holds. Suppose the hair gene looks like this in ourfive species:

WORD:   1     2     3     4     5     6     7     8     9    10chimp: AAA * GAC * GAG * CAG * GAA * TAA * TAG * GAT * CCC * CAG ...hippo: AAA * GAC * CGG * CAG * GGA * TTA * TAG * GGT * CCA * CAG ...human: AAA * GTC * GAG * CAG * GAA * TAA * TAG * GAT * CCA * CAG ...mouse: AAA * GAC * GGG * CAG * GAA * TTA * TAG * GAT * CCA * CTG ...whale: AAA * GAC * CGG * CAG * GGA * TTA * TAG * GAT * CCA * CAG ...

Now here is the part that resembles textual criticism: We can and shouldactually prepare a collation of this data. In this very simple example, we cando this by listing which species have which coding for each word. That's this(we should note that I've create a very high rate of variation. It's quite likelythat, for any given gene found in all five species, there will be less than onevariant in every ten words, rather than the seven per ten words I've illustrated).I've listed the majority reading first in all cases, taking humans as the standardin the event of a tie.

Word 1: AAA (all species)
Word 2: GAC (chimp, hippo, mouse, whale) ] GTC (human)
Word 3: GAG (chimp, human) ] GGG (mouse) | CGG (hippo, whale)
Word 4: CAG (all species)
Word 5: GAA (chimp, human, mouse) ] GGA (hippo, whale)
Word 6: TTA (hippo, mouse, whale) ] TAA (chimp, human)
Word 7: TAG (all species)
Word 8: GAT (chimp, human, mouse, whale) ] GGT (hippo)
Word 9: CCA (hippo, human, mouse, whale) ] CCC (chimp)
Word 10: CAG (chimp, hippo, human, whale) ] CTG (mouse)

As noted, we have seven variants. Four of these (words 2, 8, 9, 10) consistof singular variants. That leaves three variants we can consider meaningful:

Word 3: GAG (chimp, human) ] GGG (mouse) | CGG (hippo, whale)
Word 5: GAA (chimp, human, mouse) ] GGA (hippo, whale)
Word 6: TAA (chimp, human) ] TTA (hippo, mouse, whale)

Note that, in these variants, chimp and human agree every time except forthe singular reading at word two (we might wildly guess that this is thegene that allows humans to grow long hair; nearly all other mammals, includingchimps, have genes which give them a fixed hair length). Hippo and whale also agreein all three cases, with mouse agreeing once with chimp/human, once withhippo/whale, and once being singular. Based on this evidence, the genealogyfor these creatures is:

              proto-mammal                    |     --------------------------------     |              |               |proto-ape      proto-mouse   proto-water mammal     |              |               |  --------          |           --------      |      |          |           |      |chimp  human      mouse       hippo  whale

This is, of course, far too little evidence to go on, and the entire exampleis faked -- but the principle is perfectly valid, and shows how closely parallelgenetic analysis is to stemmatics.

There is another note here. It's one thing to have a gene, and another to useit. We mentioned above that genes are like a digital data store. They resemblecomputers in other ways, too: They resemble computer subroutines, and the wholething is a vast computer program. Like a computer subroutine, the same gene canbe used by other genes for various purposes (there are actually molecules toturn a gene on or off, and many genes respond to multiple different activatingmolecules. Indeed, they may produce different proteins based on differentactivators). The whole system is very much like passing parameters to a subroutine.

This also explains why some cells are different. Many programs are customizable --every word processor I've encountered in recent years has some sort of "work" menuon which you can stash commands you use a lot. Cells are like that, too: Very earlyon in the life of the organism, they get a chemical cue which activates a few mastergenes, and those master genes then tell them to become heart or liver or skin cells.And, in the very earlystages of development, many of those cues come from chemicals passed on by the motheror the father -- a phenomenon known as imprinting. This is a relatively recentdiscovery, and I can't go into it deeply (I don't know enough, and the field is movingso fast that whatever I could write would soon be out of date anyway). But this givesus one more analogy to scribal copying -- a scribe might well be given instructionsby his superiors to incorporate this, that, or the other set of marginalia, or tocopy in uncials or minuscules, or any of a dozen other things. The basic text --the "genes" of the manuscript -- may be unchanged even while looking verydifferent and servinga very different function.


The statement at the top of this page about scientific theories of creation-- that the Big Bang, evolution, etc. are compatible with the Bible -- probablyisn't going to convince anyone who isn't convinced, but on the off chance that thereis a person out there who actually wants to give the matter a hearing, I'm going tooffer further justification. Pointless, I know -- but hey, voting is pretty pointless(since I'm outnumbered two hundred million to one), and I still vote anyway; I justnever see anyone worthwhile elected. So I'll spend a little time tilting at thiswindmill.

I'm not even going to address Intelligent Design,since it is a farce posing as science -- and nobody believes it anyway. This isaddressed solely to the issue of whether there is a fundamental conflict betweenGenesis and scientific theories of creation (as they are understood early in thethird millenium of the common era; there is of course every expectation that theywill change. Scientific alternatives have long been offered to theBig Bang. Personally, I've never been very fond of the Big Bang -- it's rathera lot of theorizing based on very little data. But it's currently the acceptedmodel of universal formation, and it's certainly the one most like Genesis. Inany case, eliminating the Big Bang doesn't eliminate the stumbling block ofevolution; every scientific model of the universe assumes evolution as thesource of biodiversity on earth.)

I would argue as follows. The current "inflation"model of the Big Bang very closely resembles Genesis -- e.g. in the early momentsof creation, everything was a big jumble. There is no better description than"without form and void." The whole thing was a plasma. Then the threelinked forces, strong nuclear, electromagnetic, and weak nuclear, split, "andthere was light."

Gradually the whole mess settled down, and then life started to appear. It wasn'tall at once, but nowhere does Genesis say bacteria and frogs and lions were createdat the same time, merely that they were created at the same stage of creation -- afterthe creation of the universe, and before humanity. Humanity came last -- and, indeed,we are one of the last evolutionary results of one of the most recent branches of theevolutionary tree.

There are other interesting places where evolutionary theory can explain somecurious aspects of the Bible. For example, why is it that the lifespans of thePatriarchs in Genesis keep getting shorter? It must be remembered that evolutiondoesn't care what happens to a living thing after it breeds. Mayflies and PacificSalmon breed and die -- they don't even try to survive after laying their eggs.So there is no evolutionary reason not to experience senescence if youcan breed well before that.

And mutations can cause senescence. The vast majority of mutations aredetrimental -- e.g. cystic fibrosis, which is caused by a single change ina single gene, kills people young, and in most circumstances is purelydetrimental. These mutations die out (cystic fibrosisstill exists because it's a recessive gene and because it can happen bynew hot spot mutations).

But there are mutations which can have mixed effects -- suppose, e.g., thathuman females once could have only three children. If a mutation came alongthat allowed them to have twenty children, but caused them to grow old faster,well, from the standpoint of evolution, that's a good gene. Chancesare that aging is in some way a side effect of mutations like this, and theirevolutionary consequences. (In fact, I just heard a very brief item about a genethat is known to do exactly that: The gene prevents cancer but accelerates aging.In a situation where few individuals live long enough to die of old age anyway, thecancer-preventing effects are doubtless worth the cost.)

I admit that it's a long, long stretch from this to the Patriarchs, but it'san interesting case of Genesis paralleling something that really does seemto have happened. It is particularly noteworthy that the steep decline in lifespancame in the generations after Noah -- noteworthy because the Flood would have causeda sharpconstriction in the gene pool (something that geneticists have long thought to betrue because the human genome has so few variations, something which could implythat, at one point, the population shrank almost to vanishing. The disaster involvedmay not have been a flood, but there was something.) A small population,subject to genetic drift, could easily lose certain genes, including those whichpromote longevity if they affect fertility (which they seemed to do in the Biblicalcase; consider how old most of the patriarchs were when they had their firstchildren).

Again, if you think about it, the first humans were hunter-gatherers.Farming and pastoralism came later -- exactly as happened in the Bible. In theworld of science, the New Stone Age began ten thousand years ago, in the world of the Bible,six thousand years ago. A trivial difference, in geologic terms; the Bible bythis token appears to have preserved a folk memory that was largely forgottenelsewhere.

Add it all up, and it seems to me that the fact that Genesis so closelyparallels the conclusions of scientists is evidence for the truth of Genesis --it's being independently verified, even if there are a few footnotes beingadded.

The real stumbling block, it seems to me, is the word"day." The Big Bang (or the Steady State, or any other scientificmodel of the universe) didn't all happen in 144 hours -- the first parttook moments, and the rest took billions of years.

But what is a day? On earth, now, it is 24 hours. It was somewhat less inthe past -- the day was a few seconds shorter even in Biblical times; tidaleffects are slowing earth's rotation. Nor is it a constant slowing; sometimes,for peculiar reasons, the earth's rotation suddenly changes ever so slightly.

Now consider this: On Jupiter, a day is about twelve hours.

On Venus, a day is 243 earth days -- longer than Venus's period of rotationaround the sun (that is, a Venus day is longer than a Venus year).

An object in the Kuiper Belt beyond Neptune, if it is phase locked withthe sun (as is likely true in many cases), will have a day in excess of100 earth years. An object in the Oort Cloud, if it is phase locked,will have a day of thousands of years.

Theoretically, there could be a rock orbiting the sun with a year,and hence a phase-locked day,of two billion years (which would make seven days the total age of the universeso far). Kepler's third law tells us that this planet would be at a distance ofa bit under 1,600,000 A.U. (where one A.U. or Astronomical Unit is the distancefrom the Sun to the Earth). That works out to a distance of about150,000,000,000,000 miles, or 240,000,000,000,000 kilometers. That's a distanceof 25 light-years, which means that that planet does not in fact exist in oursolar system --but, conceivably, there might be such a planet around an isolated starsomewhere between galaxies. A planet with a period of half a billion yearswould be only 625,000 A. U. away; a planet with a period of a hundredmillion years would be 200,000 A. U. away. It is thus genuinely possiblethat there is a planet with a day of about 25 million years orbiting thesun.

The sun orbits the center of the Milky Way in a period estimated at220 million years. The sun has a separate day, but a planet at this distancemight be phase locked to the center of the galaxy and so have a 220 millionyear long day. The outermost stars of the galaxy appear to have an orbital periodof over half a billion years. The data I have on this is sketchy, but itis clear that a planet orbiting the Milky Way at a sufficient distance,if it is phase locked, could have a day of two billion years.

On the other hand, an extrasolar planet was discovered in 2005 that hasa year that is less than two earth days long. If there are any planetsin that solar system even closer to the sun, they might have a year that is lessthan a day long!

Even on Earth, a day is six months long at the north and south poles. Awayfrom the poles, different places have daylight at different times. If, as somehave argued, it was sunset (or high noon, or sunrise) at Jerusalem when thefirst light came, then the first day over the Pacific Ocean was not eveningand morning but morning and evening.

And then there is relativity. Time dilation. For a person or object movingat a speed near the velocity of light, a subjective 24-hour period could bea hundred years, or a thousand, or even two billion.

If you went to a planet around Alpha Centauri or Epsilon Eridani, andit had intelligent inhabitants, and you were translating the Bible, how wouldyou translate Genesis? "And there was evening, and there was morning,the first 86400 seconds, where one second is defined as 9192631770 periodsof the light emitted by cesium-133 as it shifts electrons between the two loweststates"? Go ahead, try it in English and see how many converts you get.

So what is a day? Answer: Unless otherwise specified, it's almost anyperiod of time. Classical Hebrew doesn't have words for "geologicalepoch," or "plasma," or "strong nuclear force."(It does have a word for dust, and -- interestingly in light of Genesis 3:19 --we are made of the interstellar dust which gave rise to stars and planets.)If you're going to tell the story of the Big Bang in classical Hebrew, whatcan you do except use a word like "day" for "epoch"and "water" (i.e. liquid, fluid) for "plasma"?

And are we really so arrogant as to think that God runs the entire universebased on our local earthly timescale? A God great enough to create on this scaleis surely not parochial; why create a revelation that works only on one planet?

The fact that early Biblical commentators interpreted "day" tomean "24 hours" is surely not binding on God! After all, athousand years are to God as one day....