Here, although I've said I am not qualified to study intelligent design as it relates to origins, let me take that line a little to respond to some of the things you said, Mercury. Perhaps it will be instructive to those here, to see how this debate goes.
Mercury wrote:Lothar wrote:Everybody has great fruit-fly evolution data; what none of the fields seems to have is awesome evidence that spans a significant distance in detail.
I think whales sometimes found with atavistic hind legs is pretty awesome evidence of a significant evolutionary event. It doesn't show
how whales evolved from a land-based ancestor, but it makes a pretty strong case that they did.
It does nothing of the sort. It demonstrates that whales are sometimes found with atavistic hind legs. These legs could be leftover evidence of the land-based ancestor the whale evolved from--that's one explanation. Then again, perhaps the legs function in some way for the whales that we don't know about. Or perhaps they are simply easy mutations for whales, like a sixth toe is for a human--not a sign of ancestry, just a side effect of how we develop.
A skeptic might furthermore argue that without a comprehensive set of "leftovers" indicitave of a particular a land-based ancestor, the legs should be regaurded as only a fluke. Whales breathe air and are warm-blooded, but have you got anything that would tie them to a specific land-based ancestor, or even a group of them? One might go looking and suppose that an inner earbone was similar to one animal, or a lung shape was similar to another--but without a cohesive story, this is just data mining. There is no reason to suppose these extra legs are evidence of descent--any more than to suppose a sixth toe is. They are convenient for an evolutionary explanation, but that is all.
ID would go further than this, though. If there were a scholar who made a positive-ID argument on the origin of whales, he would say that not only is there insufficient evidence to warrant a naturalisitic common descent hypothesis, but that there could not even
in principle be sufficient evidence to warrant it, due to some special feature of whales. The ID position would be that even with bulletproof evidence that whales are descended from, e.g., cows, it is more likely that aliens visited earth, captured some cows, bred/genetically engineered them, and put them in the ocean as primitive whales... than that whales evolved.
Not that anyone is making this argument with respect to whales in particular, mind you. But the skeptecism is the same, and these are the philosophical lines along which the argument proceeds. Here's another example:
Mercury wrote:PZ Meyers totally takes him to task on that one and he comes back and says, essentially, "Oh, what I meant were interesting examples. Like, each species you discover only counts as one."
I saw a comment where he said, "If you don't count the duplicates, which don't add much to our understanding, there are maybe a dozen unique hominid types? That leaves a lot of gaps in the fossil record. I could have been clearer on that point for sure."
But that makes things interesting. In the original sentence, he spoke of "the subjectivity of classifying fossils, and the fact that all of the human-like fossils ever found can fit inside a small box". Now, the subjectivity he's referring to is how sometimes there's debate about which species a fossil should be classified as. That sometimes happens with the human fossils too. So which is the actual problem? That there's such a finely-graded collection of hominid fossils that scientists can't always agree which is one species and which is another, or that all the fossils can clearly be divided into a dozen unique hominid types, and we should have far more than that? His two complaints, now that he's redefined one of them, are contradictory.
That's simplistic logic that's unworthy of you. Difficulty classifying and grading species doesn't demonstrate a continuous, finely-graded collection. Here's an example: Suppose apes were a 0 and humans were 100, and the fossils we'd found were these ones:
0 . . . . . . . . 10 11 . . . 15 16 17 18 . . 21 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 73 74 75 . . . . . . . . . . . . . . . . . . . . . . 98 99 100
Scientists could well argue whether the 10 - 21 group is one species or 3, but that doesn't make it any more continuous than it already is. The numbers and dots on that line are what you've got; how you classify them doesn't make them say more or less than they already do.
Furthermore, there's the problem of deciding which fossils are genuine human ancestors and which are evolutionary "dead ends". Not all ape-like ancient fossils are going to be "interesting" in the sense of shedding light on human origins. A lot are just going to be weird, ape-like creatures that have nothing to do with humans.
The demand for a large number of interesting human-origins fossils is not contradictory with the criticism that fossils are hard to classify and identify, or that species are hard to determine from bones. In fact, it makes it worse. Not only have you got a lot of gaps, but you can't even tell which numbers in the gaps are related
to each other or are even concurrent
species! And I'm supposed to believe you can tell which ones are related to modern humans?
So would say the evolution-skeptic: The fossil evidence for human origins is woefully inadequete to establish even common descent--that humans' ancestors were apes. We have a few fossils, but not nearly enough to be convincing, nor are any of them the
right fossils.
The intelligent-design proponent would go farther. He might argue that common descent wasn't true--he might say that there isn't sufficient fossil evidence to warrant the claim that humans descended from apes. Or he might grant you common descent--he might says he believes it, or say he has no reason to argue with it, or whatever. He's going to argue against common descent
by natural selection.
Consider intelligence.
Science fiction seems full of hope for the creation of artifical intelligence, but computer scientists have made little progress. Despite three and a half decades of hard study, theorizing, programming, and philosophy, our modern AIs can't compete with even a five-year-old's ability to think, reason, and feel. Sure, they can beat us at sheer algorithmic and computing pursuits, but to track conversation, to learn without limits, to reason in different contexts--this is totally beyond the ability of any AI we have.
Compare this to what natural selection accomplishes with animals. Deer have an instinctive tendency to freeze when they're frightened, which leads to them being hit by cars so much. If natural selection could insert into the deer AI a line that says, "Freeze... unless you're standing on pavement and staring into bright lights", a lot of deer might live a lot longer. Or of natural selection could teach fish to stay away from fires at night, or salmon to stay away from fishing-boats, or... lots of simple changes that we don't see.
Are we supposed to conclude that if natural selection can't make these simple, one-line changes in animal instinct in cases where life-and-death survival is on the line, it nonetheless managed to accomplish what decades of brilliant computer scientists can't compare with--when the rewards were so distant?
The intelligent-design proponent would say that this is impossible. He would say something like this: Darwin believed that intelligence was easy to achieve, and was simply a feature of an animal that might grow, like a tail or an eye. He wronte such thigns as, "any animal whatever, endowed with well-marked social instincts, the parental and filial affections being here included, would inevitably acquire a moral sense or conscience, as soon as its intellectual powers had become as well, or nearly as well developed, as in man." It was all very well for Darwin to believe that morals are easy to develop and that intelligence can just grow--he had not tried to actually do it. Five minutes in any philosophical moral discussion will indicate that the human moral impulse is anything
but an inevitable, simple outgrowth of "social instincts". Man's moral sense will one minute compel him to kill another man, and another minute compel him to die for him; men disagree with each other about what's right, axiomatic moral systems that give intuitively satisfactory results all the time are hard to construct, and there's a whole field of philosophy that studies it. The whole thing, and intelligent design advocate would say, is so horrendously complex and utterly beyond Darwin's simple assertion as to be
inaccessible to natural processes. Anyone who thinks man's modern moral impulse can naturally "grow" from animal instincts has not truly philosophically wrestled with it.
And that is just one aspect of man's reason. Intelligence is anything but a simple extension of problem solving. The modern difficulty we have had in writing AIs indicates to us what a
horrendously complicated thing intelligence is--and how little we understand it. It is impossible for us to engineer, and
unthinkable that nature could acidentally produce such a thing for what little survival advantage it held. Even granting common descent,
on the evidence of man's intelligence alone, it is more likely that God produced man by genetically modifying an ape than that man naturally evolved from one.
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Stepping away from devil's advocate role, here...
There are two things to consider. First, are the ID advocates right that there isn't evidence of evolution/common descent for different structures? This is a biology question, and one I'm not really prepared to assess. Biology isn't really my thing, and I fully expect that my post looks ignorant to anyone whose thing it is. But nonetheless, the ID advocates seem to think they have an anti-evolutionary case here--and the reactions and conversions resulting from some of their earlier books make that seem plausible to me.
But the second question is the more interesting one to me. Can you say, "This feature is so complex / evidently designed that nature could not engineer it
in principle, regaurdless of the evidence for common descent?" On the one hand, given the immensely wonderful things to be found in nature, the question has a lot of intuitive force. I mean, seriously--human intelligence, evolving by accident, for the advantage tool use gives? Who needs such human things as an appreciation for beauty, a capacity for higher reasoning, and a moral impulse for
that? These things--all so horrendously complex and difficult to even rationally analyze... are supposed to have happened by accident? To assist in survival? The intuition balks.
Then again, one could invoke Carl Sagan--given billions and billions of years and billions and billions of planets... who knows what could happen? This is an intuitively forceful argument as well.
This is why I find the ID argument so interesting. I want to know--can you make that first type of argument? Is that valid? It sure seems intuitively forceful, but... so what? What does that really
tell us? I'm not convinced you can rationally apply ID to origins, but part of me suspects you can. So I remain a skeptic of both. Though I do have my suspicions that there is something
to ID, I can't claim to know that even in an abstract sense. And in a biology sense? Heh... I'll get back to you once I've had a chance to re-read my 9th grade biology book to remember all the things I've forgotten.
Still... I read about some of the stuff in nature--butterflies with LEDs and bacteria with outboard motors and birds with time-compensating sundials, and I cannot escape the sense that there is something
to the argument. I just couldn't tell you what.
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Mercury wrote:
Anyway, the "small box" claim is widely spread around in creationist and ID circles (note I separated the two!). I think it was first popularized by Jonathan Wells in his book Icons of Evolution. It's a quote from Henry Gee, an editor for Nature who said that evidence for human evolution "between about 10 and 5 million years ago -- several thousand generations of living creatures -- can be fitted into a small box". It's pretty hard to believe that he wasn't referring to this when he made the claim. It's too bad he wasn't willing to simply admit a mistake. After all, as you've said, these misconceptions actually further his main claim about how hard it is to get good information on this topic.
Ok, you made me look. Wells does use the quote--here:
Jonathan Wells, in 'Icons of Evolution', on p. 220, wrote:
... Henry Gee, Chief Science Writer for Nature, is even more pessimistic. "No fossil is buried with its birth certificate," he wrote in 1999, and "the intervals of time that separate fossils are so huge that we cannot say anything definite about their possible connection through ancestry and descent." It's hard enough, with written records, to trace a human lineage back a few hundred years. When we have a fragmentary fossil record, and we're dealing with millions of years--what Gee calls "Deep Time"--the job is effectively impossible.
Gee regaurds each fossil a "an isolated point, with no knowable connection to any other given fossil, and all float around in an overwhelming sea of gaps." He points out, for example, that all the evidence for human evolution "between about 10 and 5 million years ago--several thousand generations of living creatures--can be fitted into a small box." Thus the conventional picture of human evolution as lines of ancestry and descent is "a completely human invention created after the fact, shaped to accord with human prejudices." Putting it even more bluntly, Gee concludes, "To take a line of fissils and claim that they represent a lineage 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."
Dunno if you'd call that quote-mining or not, but given the force and number of quotes, it seems unlikely. I'd have to see the book. The citations are from
In Search of Deep Time: Beyond the Fossil Record to a New History of Life (New York: The Free Press, 1999).
It's funny that it loses the qualification in later quotes, but given the larger story (shoot, even the title of the book), it sure seems like a faithful representation Gee's view of the picture. I don't know where the misquote you cite would have started, Mercury--at any rate, Wells didn't start it. It's possible someone else did, or that Scott made the analogy completely independantly. I wonder what probability/pattern/design inferences we can rationally draw about that.
