What Vestigility Is and Isn't

Ray Comfort recently learned something that I had learned back in Dr. Karpov's Biology 101 For Non-Majors: The appendix is a breeding ground for beneficial gut bacteria. That's pretty cool, but it has Ray mad as hell - He's miffed that scientists haven't "apologized" for figuring out what the appendix does. (Seriously, read his post.)

See, Ray doesn't exactly understand what folks mean when they refer to the appendix as "vestigial". He thinks that saying the appendix is vestigial means that it has no function whatsoever, but he's wrong. A structure being vestigial doesn't mean that it has no function! For a structure to be vestigial means that it seems to have lost "most or all of its original function". That doesn't preclude its having a new, different function. So how does the appendix measure up with regards to this definition for vestigiality?

Well, for starters, there are structures analogous to the human appendix in lots of other creatures. In primarily herbivorous animals this structure is called the cecum and is generally relatively large. It aids in the digestion of plant material. A koala, for example, has a titanic cecum that (if removed and stretched out) is actually longer than the animal itself.* On the other hand, carnivorous creatures tend to have a small cecum that has been either partially or completely replaced by an appendix.

Humans are the same way - We have a sissified little cecum with an attached appendix and these structures are no longer useful for helping us digest plants. Instead they serve as a breeding ground for gut flora. Sounds pretty vestigial to me.

*Koalas are also neat for another evolutionary reason: The "forefinger" of the koala has been modified with time to the point that it now serves as a second "thumb" in order to give the beast a firmer grip when climbing trees.

Confronting the Creationists With Science...

Alright, with the release of Expelled looming like on the horizon like some big ridiculous monster, I thought it'd be fun to post a video about the relationship of humans to our great ape cousins. For added emphasis, I'm referring readers not to an atheist biologist like Richard Dawkins, but instead to devout Catholic biologist Kenneth Miller, holder of a Ph.D. in biology and a professor at Brown University. This is a fascinating video taken from a much longer 2 hour talk available here. In this clip, Miller talks about the evidence of chromosome fusion in humans, explaining why humans have 23 pairs of chromosomes while great apes have 24. Were there no evidence of a fusing of chromosomes in human beings, the theory of common descent between humans and great apes would be disconfirmed. On the other hand, mapping of the human genome shows an anomalous placement of centromeres and telomeres in the human genetic code that provides powerful evidence of chromosome fusion and, therefore, of common descent. Enjoy.

Expelled by Design...

Well, Ben Stein's Intelligent Design screed Expelled is going to start showing up in theaters this Friday, though it's only running in two theaters in my city. I actually saw a commercial for it on TV for the first time this morning. I must admit that I have some morbid interest in seeing the film, though I've no interest whatsoever in supporting its creators by paying to do so. Expelled is little more than a collection of the same tired old creationist arguments mixed in with whining about about "scientific elitism" and weird accusations that Darwin caused the Holocaust.

There are two things that strike me as missing from all the pre-release material on Expelled, the first being the obvious question that, if somehow ID turned out to be true in the face of all on-going scientific research, why would that naturally lead us to the conclusion that the Judeo-Christian God was behind it? Why not Odin, Amaterasu, Ganesh, Marduk, or Cthulhu? What would it prove about any god? Mightn't it just prove that there are aliens and that they created humanity? Because ID is just a repainted version of fundamentalist Christian creationism, it makes an unspoken assumption that if nature were shown to be designed by an outside intellect, it must've been Yahweh that did it. But what leads them to that assumption? Why didn't Ben Stein interview this guy?

The reason is that Stein and his Expelled cronies aren't interested in non-Christian versions of ID is that they're specifically out to tout biblical creationism in the guise of science. Not that I'm claiming that the alien guy is doing any more science than the IDers (actually they're probably working on about the same level), but it's telling that the traditional IDers want nothing to do with these guys. They're all making about the same claims, but the ID crowd wants to make sure that its audience understands, without having to say so, that the operator behind all this meant to be Yahweh.

What's double fun here is that any time you bring up the whole "intelligent design by aliens" to a traditional IDer, you'll get a response along the lines of "Aliens complex enough to create human beings are also too complex to have arisen by chance*, so what designed them?" The reply, of course, is that an omnipotent deity must by definition be far, far more complex than either humans or aliens, so where did it come from? Was it designed by something else? Where did that come from? Did it, and only it, evolve? If a deity has existed for all eternity with no beginning or end, can't one ask, rhetorically, why a static universe in which the building blocks of life have always existed is not at least equally as plausible?** Most IDers have no answers to these questions because their are operating under the assumption that the ID "designer" is meant to be Yahweh.

Also conspicuous by their absence are any prominent Christian scientists who accept evolution. As usual, I'm going to trot out Human Genome Project head Francis Collins, who is an eminent geneticist and also a devout believer in evangelical Christianity. Collins is willing to go to the mat with Richard Dawkins about the existence of God (Collins is big into the anthropic argument.), but he is convinced of the reality of evolution by natural selection after having spent his entire professional life working exclusively in the field of genetics! Where is Collins in Expelled? What about Catholic biologist Ken Miller, author of Finding Darwin's God and outspoken foe of creationists of all stripes? Why isn't he in Expelled?

The answer here is easy - Expelled's producers felt that Christian evolutionary scientists would "confuse the audience". Something that the creators of Expelled want to sweep under the carpet is that the vast majority of Christians working in the biological sciences understand evolution by natural selection to be, for all intents and purposes, an established fact. By refusing to acknowledge that anyone can both be a Christian and accept evolution by natural selection, the Expelled crew is working hard to manipulate their Christian viewers into siding with them by fiat, essentially saying that "Christians aren't allowed to accept evolution".

So yeah, Expelled is coming to theaters on April 18th, but it might behoove moviegoers to think for a moment about some of the perspectives that have been expelled from Expelled.

* Note the use of the word "chance" in ID/creationist-speak, rather than anything more illustrative of the proper evolutionary view of "random mutations being acted upon by non-random selection pressures."

** Sure such a cosmological scheme doesn't jive with modern physics, but doesn't that make it all the more appealing? Stick it to Big Physics by asserting your right to believe in a static universe!

Creationists want it both ways...

I've been spending an exorbitant amount of time lately poking the creationists over on Ray's blog. I don't really expect to "convert" anyone, but it's interesting to see the ways that they frame their arguments and whatnot. Now, I largely believe that the issue of evolution is problematic for some breeds of Christian because it calls in to question their privileged place in the universe. Note that I say "their" rather than "ours". There is a tremendous arrogance among the "saved" that I've spoken of on here before, and I can only say that, among the followers of Ray's blog at least, my original griping on the subject was a gross understatement of the truth.

One of the most interesting things I've encountered thus far is the strange relationship some of these folks have with science, as both an institution and a methodology. Whenever science fails to support their preconceived notions it is uselessly and dogmatically naturalistic you see, but when it coincides with their beliefs it is not only correct but nearly infinite in its persuasive power. I suspect some of this comes from the ongoing debate between the skeptics and the believers on Ray's blog. Ray's brand of Christians seem incapable of grasping the idea of existing without out and out worshiping something, so when skeptics talk about science as a useful methodology for understanding the world we are naturally saying that we worship it. It's a peculiar thing to wrap your mind around, but some of their statements make more sense (more narrative sense, anyway) when you finally see that some of them have that perspective.

One thing that is of interest to me is the degree to which creationists think scientists are in (dis)agreement about evolutionary theory. Many of them seem to think that there's an enormous amount of debate within the scientific community as to whether or not evolution in the broad sense is true. Indeed, a recently Pew survey indicated that something like 54% of lay people think that scientists in general support evolution. Read that again. 54% of lay people think that scientists in general support evolution. What a weird survey. Actual surveys of scientists reveal acceptance of evolution by anywhere from 95% to 98.5% of scientists. In fact, the good ol' "Scientific Dissent From Darwinism" that the Discovery Institute is so proud of represents a minuscule number of scientists (approx. 700 out of nearly 500,000) and its numbers are likely padded by its pallid wording that "Careful examination of the evidence for Darwinian theory should be encouraged." Hell, I think almost everyone would agree with that. Add to that the fact that numerous signatories on the list are either not in biological science fields or openly admit that their concerns about evolution are ideological and you have a list of names that just doesn't mean much.

Another question that never quite gets answered is what creationists make of scientists with both strong Christian and strong bio-sciences backgrounds who believe in God but also accept evolution as settled fact. The figurehead of this group is the eminent Francis Collins, whose belief in God has been manifested in public debates with atheist scientists like Richard Dawkins but whose entire professional career has been spent doing legitimate experimental work and, among other things, heading up the Human Genome Project. Here's a man whose faith is not in doubt but whose lifetime of work in the fields of biology and genetics has left him thoroughly convinced of evolution's reality. It is scientists like Collins who make it impossible for the creationists to have it both ways when it comes to science.

I've been asking the creationists over on Ray's blog what they think of Collins for weeks now and I've gotten no replies. I guess, as with the evidence of evolution, they choose to pretend that he doesn't exist.