Wednesday, May 09, 2007

Evolutionary mirror-reading

(Posted on behalf of Steve Hays)

Below are some excerpts from Henry Gee’s book on cladistics. My transcription preserves the original emphases.




Many of the assumptions we make about evolution, especially concerning the history of life as understood from the fossil record, are, however, baseless. The reason for this lies with the fact of the scale of geological time that scientists are dealing with, which is so vast that it defies narrative. Fossils, such as the fossils of creatures we hail as our ancestors, constitute primary evidence for the history of life, but each fossil is an infinitesimal dot, lost in a fathomless sea of time, whose relationship with other fossils and organisms living in the present day is obscure. Any story we tell against the compass of geological time that links these fossils in sequences of cause and effect—or ancestry and descent—is, therefore, only ours to make. We invent these stories, after the fact, to justify the history of life according to our own prejudices.1

Fossils are never found with labels or certificates of authenticity. You can never know that the fossil bone you might dig up in Africa belonged to your direct ancestor, or anyone else’s. The attribution of ancestry does not come from the fossil; it can only come from us. Fossils are mute: their silence gives us unlimited licence to tell their stories for them, which usually takes the form of chains of ancestry and descent…Such tales are sustained more in our minds than in reality and are informed and conditioned by our own prejudices, which will tell us not what really happened, but what we think ought to have happened. If there are “missing links,” they exist only in our imaginations.2

Once we realize that Deep Time can never support narratives of evolution, we are forced to accept that virtually everything we thought we knew about evolution is wrong…If we can never know for certain that any fossil we unearth is our direct ancestor, it is similarly invalid to pluck a string of fossils from Deep Time, arrange these fossils in chronological order, and assert that this arrangement represents a sequence of evolutionary ancestry and descent. As Stephen Jay Gould has demonstrated, such misleading tales are part of popular iconography: everyone has seen pictures in which a sequence of fossil hominids—members of the human family of species—are arranged in an orderly procession from primitive forms up to modern Man.3

To complicate matters further, such sequences are justified after the fact by tales of inevitable, progressive improvement. For example, the evolution of Man is said to have been driven by improvements in posture, brain size, and the coordination between hand and eye, which led to technological achievements such a fire, the manufacture of tools, and the use of language. But such scenarios are subjective. They can never be tested by experiment, and so they are unscientific. They rely for their currency not on scientific test, but on assertion and the authority of the presentation.4

Whether you believe the conventional wisdom that our own species Homo sapiens descended in seamless continuity from the preexisting species Homo erectus depends not on the evidence (because the fossil evidence is moot) but on the deferment of your lack of knowledge to the authority of the presenter or whether the presentation of the evidence resonates with your prejudices.5

The story of human interaction with fossils represents an example of how experience and belief have a powerful effect on interpretation and demonstrates why scientific truths can only be temporary. Today, we see fossils as the remains of creatures that once lived. However, this nature is not inherent in the fossils. It is our immersion in a century and half of Darwinian thought, not the fossils themselves, that gives us the capacity to see fossils as kin to things that were once as alive as you or I.6

The intervals of time that separate the fossils are so huge that we cannot say anything definite about their possible connection through ancestry and descent.7

The conventional portrait of human evolution—and, indeed, of the history of life—tends to be one of lines of ancestors and descendants. We concentrate on the events leading to modern humanity, ignoring or playing down the evolution of other animals: we prune away all branches in the tree of life except the one leading to ourselves. The result, inevitably, is a tale of progressive improvement, culminating in modern humanity. From our privileged vantage point in the present day, we look back at human ancestry and pick out the features in fossil hominids that we see in our selves—a big brain, an upright stance, the use of tools, and so on. Naturally, we arrange fossil hominids in a series according to their resemblance to the human state.8

The conventional, linear view easily becomes a story in which the features of humanity are acquired in a sequence that can be discerned retrospectively—first an upright stance, then a bigger brain, then the invention of toolmaking, and so on, with ourselves as the inevitable consequence.9

New fossil discoveries are fitted into this preexisting story. We call these new discoveries “missing links,” as if the chain of ancestry and descent were a real object for our contemplation, and not what it really is: a completely human invention created after the fact, shaped to according with human prejudices. In reality…each fossil represents an isolated point, with no knowable connection to any other given fossil, and all float around in an overwhelming sea of gaps.10

Just because the unicorn looks something like a bull or a horse to us, this does not imply that a unicorn is a missing link between these two animals. Horses and bulls are contingent; they just happened to offer themselves as models because they are familiar and available. Perhaps in another part of the world, a unicorn would be seen as a mixture of a camel and a kudu, but a unicorn would not be a missing link between those animals either.11

This task had very little to do with what the fishes were like as living animals. All I had were fragments that I could link to larger and more certainly known fragments that were sufficiently informative to have a name. I might as well have been doing the same thing with stamps, or cigarette cards. The relationships that these fishes had with living animals is so distant that any attempt to clothe them in flesh, to make them swim, requires a leap of faith.12

However, this leap must in some degree be fuelled by comparison with the animals that live around us today. If this were not possible, we would not be able to make any sense of fossils at all. When we look at pteraspids now, we interpret them in terms of lampreys: that is how they “make sense” to us. But the model of a pteraspid in terms of a lamprey is as provisional as that which once linked pteraspids with squid.13

The quest to interpret fossils in terms of modern models rests on the assumption that all life on Earth has a common ancestry, because we can interpret past life only in terms of other living organisms. If this were not possible, we would not recognize the fossils of animals as animals at all. We’d just see them as rocks.14

Crucially, you should have a clear idea about the position of the organism in nature before speculating about the function of its various parts. Let me explain. Let’s say that you have discovered that unicorns use their horns to kill dragons. Using this information, you could spin a tale about the importance of the horn in unicorn evolution: unicorns evolved in dragon country, where possession of horns was an asset. Unicorns without horns would all be charred to ashes by the fire-breathing dragons. Only those unicorns with horns survived to perpetuate the species.15

This story sounds plausible, but like the story about the evolution of tetrapod limbs, it cannot be tested. What is more, if you use your prior (and untestable) assumption that the unicorn evolved its horn to kill dragons as a guide to the unicorn’s relationships, you cannot then use this information in any subsequent test of the function of the unicorn’s horn. Why? Because you have already assumed that you know the horn’s function, even before you run the test. You have loaded the dice to tell you what you want.16

Misinterpretations about “adaptive purpose” ignore the fact that natural selection is a blind and undirected consequence of the interaction between variation and the environment. Natural selection exists only in the continuous present of the natural world: it has no memory of its previous actions, no plans for the future, or underlying purpose. It is not a winnowing force with an independent existence that can b e personified, like Death, with his black cowl and scythe.17

Artificial selection is an imperfect metaphor for natural selection because breeders quite obviously do have intelligible reasons for why they select some traits and not others. Unlike natural selection, breeders have memories, plans, and purposes. They select for the same traits, generation after generation, to produce a discernible trend. Natural selection could hardly be more different18

To take a line of fossils and claim that they represent a linage is not a scientific hypothesis that can be tested, but an assertion that carries the same validity as a bedtime story—amusing, perhaps even instructive, but not scientific.19

Ornithologists, who study modern birds, regard Archaeopteryx as an ancestor and an icon. Given that they have already judged where Archaeopteryx fits into the history of life, they look at the fossil and see exactly what they expect to find—birdlike features…Archaeopteryx has feathers, so it is a bird by definition. Its archaisms are only to be expected, given the fossil’s great antiquity when compared with other bird fossils. Because they study modern birds, ornithologists will, naturally, tend to see bird evolution in terms of perceived adaptations to birds’ current, airborne niche.20

Palaeontologists, in contrast, come to Archaeopteryx with a different search image…To palaeontologists, Archaeopteryx looks very similar to members of a group of dinosaurs called theropods….In this light, palaeontologists tends to see the feathers of Archaeopteryx as intriguing decorations for the body of a theropod dinosaur, not as central, key features essential for explaining the course of evolution in birds.21

The finds are 4.4 million years old and come from a place called Aramis. “This is the earliest-known hominid,” says White, proudly, but with a touch of self-deprecating humour that demonstrates a sensitivity to the inevitably piecemeal nature of human fossil remains, in which all the evidence for the hominid lineage between about 10 and 5 million years ago—several thousand generations of living creatures—can be fitted into a small box.22

There is therefore nothing special, advanced, or progressive about bipedality—only the fact that it is we who are bipedal, and it is we who are writing the book, makes it so.23

To complicate matters, brain volume can vary enormously among individuals in a species, with no discernible connection to intelligence.24

1 In Search of Deep Time: Beyond the Fossil Record to a New History of Life (Cornell 2001), 1-2.

2 Ibid. 2.

3 Ibid. 4-5.

4 Ibid. 5.

5 Ibid. 8.

6 Ibid. 9.

7 Ibid. 23.

8 Ibid. 32.

9 Ibid. 32.

10 Ibid. 32.

11 Ibid. 54.

12 Ibid. 61.

13 Ibid. 61.

14 Ibid. 82.

15 Ibid. 87-88.

16 Ibid. 88.

17 Ibid. 96.

18 Ibid. 96-97.

19 Ibid. 117-18.

20 Ibid. 180.

21 Ibid. 180-81.

22 Ibid. 201-02.

23 Ibid. 214.

24 Ibid. 214.

17 comments:

  1. Henry Gee has taken great exception to his work being exploited by creationists, especially since "Darwinian evolution by natural selection is taken as a given" in his book.

    See:
    http://www.ncseweb.org/resources/articles/3167_pr90_10152001__gee_responds_10_15_2001.asp

    http://blogs.nature.com/news/blog/2006/04/the_fish_that_crawled_out_of_t.html#comment-7176

    Other: http://stevereuland.blogspot.com/2006/04/wittlessly-quote-mining.html

    ReplyDelete
  2. Notice the defensive reaction. All I did was to transcribe some extensive, verbatim quotes from Gee's book, without offering any editorial commentary of my own. I didn't say if I agreed or disagreed with Gee. I didn't draw any inferences from his arguments regarding the creation/evolution debate. Yes, indeed, Gee believes in evolution. I was quoting directly from a leading evolutionary theorist, in his own words. I said nothing about the content.

    The anonymous commentator is simply exposing his own intellectual insecurities vis-a-vis evolution by his knee-jerk reaction. Thanks for unintentionally revealing so much about yourself. Your admission speaks volumes.

    ReplyDelete
  3. BTW, the Discovery Institute responded to Gee's complaint:

    http://www.reviewevolution.com/press/pressRelease_NCSECampaign.php

    ReplyDelete
  4. Ready your hardhats and headlamps, it's quote mining time!

    Yawn.

    Notice the defensive response by Steve. Clearly we're onto something here. It speaks volumes.

    So Steve, since you carefully avoided content or context, what DO you actually think regarding this information? Or are you just trolling?

    ReplyDelete
  5. AngryAtheist5/09/2007 5:55 PM

    Steve, don't you know that to quote an atheist in his own words is the easiest way to discredit him? PLEASE BE MORE SENSITIVE OF OUR FANATICALLY HELD BELIEFS!!

    ReplyDelete
  6. Steve,

    Thank you for this. You're right, I think 'orthodox Darwinism' is a joke, scientifically and philosophically. It's sad to see so many young people holding so tenaciously to a ridiculous theory. All the years they've been trying to beat you with the club of 'old school Darwinism" has been a wasted attempt, since the club is made of paper.

    Now, it is correct that I hold to evolution. I disagree with 'creationism.' But, I'm smart enough to see what's going on here. You're simply pointing out the flaws in the priestly and popish system of Darwinism that I am fighting against.

    To be sure, you and I will have our own debates, but these sorry sacks are out. You're thinking, "one down, one to go." I respect that. Thanks for posting this so that the teenage and debunking audience of pre-enlightenment Darwinism can see the error of their ways. You and I may not agree, but, as they say, "The enemy of my enemy is my friend."

    I should say, though, that I am tempted to drop my whole theory since the anonymous atheist commentors here are acting like the missing link between man and ape. So, these cro-magnum atheists may have disproved us after all!

    ReplyDelete
  7. Gee, Steve, one would think you'd like to actually present the man's words with a lil' context so no one is led astray. But then of course, you are just posting random selections for giggles. Sure, gotcha. So what other books do you feel like using "some extensive, verbatim quotes from", just for fun "without offering any editorial commentary" and devoid of "inferences"? War and Peace?

    ReplyDelete
  8. See how certain commentators take offense to the quotes, and they claim they are taken out of context...but they don't bother to put them into their context for us.

    At least when critics misuse Scripture, we take the time to exegete it for them and place it in the proper grammatical and historical context. Why can't these critics do the same with these quotes from Gee?
    The last anonymous commenter wants Steve to put these quotes in context. Does it follow then that this commenter knows they were taken out of context? If so, then will he then place them in context in order to show Steve's alleged duplicity? If he doesn't know the context, then how does he know Steve took them out of context?

    ReplyDelete
  9. I must say that I’m confused, unsettled, and taken aback by the reaction of some secular commenters. I thought it went without saying that I posted a series of statements by a leading evolutionary theorist to make a case for evolution.

    I mean, Gee believes in evolution. You only have to do a Google search to find that out. So when an evolutionary theorist writes a major book on evolution, he’s going to speak in favor of evolution, right?

    Up until this afternoon, I was a card-carrying adherent of naturalistic evolution. Richard Dawkins was my hero.

    But now I’m beginning to harbor serious doubts. Indeed, the reaction of these commenters has shaken my faith in evolution to the core. For they—the commenters—are the ones who construe my innocent little post as a slam against evolution.

    But, of course, I never said that, now did I? I never said anything. So they must be getting their interpretation straight from Gee's very own words!

    How can they take my post as being anti-evolutionary, given that I was only quoting Gee, without adding my own commentary, unless they tacitly admit that his statements are damaging to evolution?

    And as I reread he said in light of their reaction, I can now begin to see how his statements could well be taken as undermining evolutionary theory. It’s very disturbing.

    They insinuate that I’ve quoted him out of context, but how do the statements cited misrepresent his position? Are they claiming that all those quotes are not representative of his true position?

    I’ve given author, title, publication date, and pagination.

    ReplyDelete
  10. A few impressions about Henry Gee himself:

    1. Gee is an iconoclast who can't seem to destroy the last icon. Despite having called evolution into serious question, why does he still hang onto it? Basically, I just wonder what his rationale is? Maybe he's got a legitimate one?

    In any case, now that he's called into question evolution, why does he seem to be so upset that some people are moving on to the next logical step and looking for alternatives to evolution? Given his book, to be fair he should at least be agnostic in regard to evolution, shouldn't he?

    2. Insofar as I can tell, Gee seems to equate creationism to YEC (at least at certain times). That is, to right-wing, uneducated, fundy Christians from the backwoods who believe God created the world in six literal days. But is this accurate? For starters, I wonder whether Gee has explored YEC and OEC arguments or if he's just dismissing them out of hand in reaction to a certain caricature he has in mind? Behaving towards them as other evolutionists might behave towards him?

    3. With specific regard to the Discovery Institute, and as they themselves have pointed out, they are not all YEC. In fact, many of them are not.

    4. The Discovery Institute is not promoting YEC. Nor are they misrepresenting what Gee has written. As I read them, they're merely calling into question evolution -- just as Gee himself does.

    Or does Gee not want others to publicize his publications?

    5. What's "political" about promoting creationism, anyway? And even if it is "political" to promote creationism, which is apparently what has rubbed Gee the wrong way, so what? After all, if even atheists can promote their values in our society, why can't others do the same?

    6. However, since Gee has identified himself as a believer in God as well as an evolutionist, I don't see why he would have any difficulty with the Discovery Institute, per se. But Gee doesn't want to be identified with them.

    ReplyDelete
  11. Gee:"But if you ‘believe’ in the Bible as literal truth (as Ms Sears does) rather than as an instructive, insightful and morally uplifting part of our heritage (as I do), then no advance is possible"

    Gee sounds as if he's a 'cultural Christian' who likes the label 'Christian' because it makes him sound like a 'good' person, but isn't peachy keen on the parts in the Bible about sin, wrath, and hell.

    ReplyDelete
  12. Steve,

    They insinuate that I’ve quoted him out of context, but how do the statements cited misrepresent his position? Are they claiming that all those quotes are not representative of his true position?

    I’ve given author, title, publication date, and pagination.


    It actually isn't just the commenters who have claimed that Gee's words have been misused -- it is Gee himself: link

    Simply put, Gee is a scientist who wrote this book to clarify how the mysteries of evolutionary biology are put together -- what methods are used and what assumptions are made. Gee himself says at the outset of the book, "if it is fair to assume that all life on Earth shares a common evolutionary origin..." (p. 5, paperback), and he moves throughout the book with this assumption. So any portrayal of the man's words as though they undercut common ancestry is, at best, ill-informed, and at worst ill-intentioned.

    Personally, I can read these quotes and understand what he is saying -- most of it applies to those who mistakenly assume linear descent from fossil to fossil, when in fact we know that most of the species we find are cousins, not direct ancestors. That is what he meant about the "stories" and the "missing links". And it applies well to human descent -- the true picture of human descent is best represented by this sort of "bush" cladogram, and not the unscientific and inaccurate [when viewed as lineal direct descent] "ascent of man," which is nonetheless a very popular icon.

    Thus, when he refers to the question of man's earliest common universal ancestor (direct descent) being erectus, he is not intimating that it is possible that man "poofed" into being, but that the possibility of erectus being our direct ancestor is not beyond serious question. But Gee believes that something was our direct ancestor, if even an as-yet-unnamed species. That much is clear from his assumption of common ancestry, right?

    At any rate, while it seems to have bothered some that you posted this, it doesn't bother me. If Gee were a critic of evolution or not has little bearing on its validity as scientific fact. There are plenty of detractors of evolution, and if Gee were but one more, I could care the less, especially if he was one of the 0.01% of PhD biologists who rejected common ancestry, and even more so given his religious views.

    Patrick,

    6. However, since Gee has identified himself as a believer in God as well as an evolutionist, I don't see why he would have any difficulty with the Discovery Institute, per se. But Gee doesn't want to be identified with them.

    Perhaps his reasons are best laid out by Gee himself:

    "As such, I regard the opinions of the Discovery Institute as regressive, repressive, divisive, sectarian and probably unrepresentative of views held by people of faith generally. In addition, the use by creationists of selective, unauthorized quotations, possibly with intent to mislead the public undermines their position as self-appointed guardians of public values and morals." (source)

    ReplyDelete
  13. Downs,

    I have said that I don't want my words misused, i.e., as propoganda for creationists, but that does mean that Stve has misrepresented my words.

    So, car to show how Steve has misrepresented me? Thanks.

    ReplyDelete
  14. "As such, I regard the opinions of the Discovery Institute as regressive, repressive, divisive, sectarian and probably unrepresentative of views held by people of faith generally. In addition, the use by creationists of selective, unauthorized quotations, possibly with intent to mislead the public undermines their position as self-appointed guardians of public values and morals."

    A. The Discovery Institute is not composed of creationists.

    B. How is it that a group that is composed of people from a diversity of ethnic, social, and religious backgrounds divisive, regressive, etc.?

    C. There are agnostics at the DI, as well as Jews, Christians, Hindus, and others. How is this at all "sectarian?"

    ReplyDelete
  15. Heck, guys, why don't you just ask me? Unlike God, I'm available for comment, and you don't have to divine what you think I said by some kind of Talmudic interpretation or reading chicken entrails -- Henry Gee

    ReplyDelete
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