Tiktaalik has dominated a lot of the media discussion about evolution in the last few years. For those who don't know, Tiktaalik is a fossil "fish-o-pod" found in Canada, that is claimed to be an "intermediate form" between fish and early tetrapods (tetrapods are four-limbed creatures). In addition, it was claimed that it was in the evolutionary-correct position in the fossil record for the fish-tetrapod transition (late Devonian).
Now, the basic problem in Tiktaalik is that it isn't "transitional" so much as mosaic - that is, it has features of "earlier" and "later" creatures, but no features that might be considered "in transition". Each feature that it has, it has fully. This indicates that, if it did "evolve", it did so non-Darwinistically - that is, the information seems to have already been in the gene pool, and was merely activated. On the other hand, in absense of a mechanism of macroevolution, there is no reason to think that it evolved at all. And from a flood geology perspective it gets even more interesting, but I'll leave that for the moment.
In addition to all this, there is a certain kind of criticism that emerges from lay people that you don't tend to find among experts. That criticism is of the form of "is this really all the information there is? Does it really add up the way you say it does? Is it not possible that there is other evidence out there that you just haven't found yet - perhaps because you weren't looking for it?"
Now, this kind of criticism is usually just ignored by experts, but I personally think that it is epistemologically valid, and an important part of public discourse. The fact is, every discipline needs to be confident in its own ability to find truth. However, equally important, is that the public should not grant each discipline the same amount of credulity that it grants for itself. A discipline can't go anywhere if it has to spend all its days proving its assumptions. On the other hand, if you can't prove your assumptions fully, then your findings are not binding on others. If someone has a larger worldview, then different aspects may be in competition. Why should a person give up belief X which is important to them and which they believe they hold validly, when they don't agree with the assumptions of contradictory belief Y, especially if it is relatively unimportant to their daily lives?
The reason I say all of this is that, in the case of Tiktaalik, it is the lay criticism that wound up being correct. Let's look at a new article that came out in Nature. For those of you who are not nature subscribers, here is a short news article on the subject.
What they found is, according to evolutionary timescales, a full-fledged tetrapod existed about 20 MILLION years prior to Tiktaalik. While Tiktaalik was a transitional, this thing was fully-tetrapod. So, this blows any story about Tiktaalik and evolution completely out of the water. Tiktaalik has nothing to do with the evolution of tetrapods, because, if evolution is correct, full-blown tetrapods predated the transitional species by about 20 million years.
It's dangerous to put your faith in circumstantial evidence, because the facts can change that quickly. Yesterday it was an open-and-shut case for Tiktaalik being found right where it was supposed to be in evolutionary transition. Today, it is more than 20 million years out-of-date. I say "more than" because, according to evolutionary theory, the tetrapods would have still required time to evolve before this creature existed.
So here's where it gets really interesting - the new find is footprints. Here's a few things that don't usually get a large mention in introductory textbooks:
The interesting implication of #1 is that there is NO WAY AT ALL to infer from the fossil record how long something has been in existence. If we can verify that the fossil record can be off 100 million years in one direction, if we assume that the same thing can happen in the other direction, then that means that you have a possible margin of error of about half of the phanerozoic era (the phanerozoic is the complete fossil-bearing section of the fossil record). How can you possibly have a detailed evolutionary progression when you can have this kind of discrepancy between fossil evidence and reality? If the best you can do is establish which half of the geologic column they existed in, how good is your data, and how are you going to derive evolutionary expectations from it?
Let's look at the second idea - that the fossil record actually seems complete. There are many ways of measuring completeness. The interesting thing is that most of them point to the fossil record being essentially complete, at least to the biological "family" level. That doesn't mean that we won't find anything new, just that we've probably found more than we haven't. So, this makes an interesting corrective to the preceding paragraph. Maybe the completeness of the fossil record gives us confidence that most of the extents of organisms are well-represented in the fossil record, and these two (and some others) are merely anomalies. That could almost work, except...
Why on earth do trace fossils precede body fossils? As the Nature article on Tiktaalik points out:
Trace fossils — footprints, trackways or trails — are fascinating but often frustrating sources of information. Body fossils of the track makers almost never occur in the same rock beds, so complicating interpretation.
It is much harder to preserve a trackway than a bone. So why do we know most organisms by trace fossils before we know them as body fossils, and why are the two rarely found in the same rock beds?
The answer, perhaps, is contained in an old Creation-oriented paper titled Stratigraphic Distribution of Vertebrate Fossil Footprints Compared with Body Fossils
In this paper, Brand and Florence argue that the reason for this is that it evidences fleeing behavior. The flood didn't happen all at once. It waxed and waned until it covered the earth, which didn't happen until day 150. Until then, the increasing floods would still have had tides from the moon, and gone in and out over increasing landmasses. Therefore, if there is a footprint, it is probably of a living creature, not a drowning one. If there is a body fossil, it is probably a drowned creature. So if the waters had temporarily receded, new trackways could be lain. When the waters come back and deposit a new layer, they are killing off organisms into a different rock bed.
Also, as Kurt Wise has pointed out recently, if the fossil record is of a global flood, we should expect much more completeness than the evolutionists.
In any case, this is getting to be rambling. My main point is that this new fossil find has very interesting implications for both creationists and evolutionists, and tends to validate thought-patterns of lay critics of evolution.
I wrote this last night but forgot to publish it. In the meantime, several other people have chimed in on the new tracks:
A recent development has been that some science journals are now publishing papers that deal with Intelligent Design. Unfortunately, at least so far, they are only looking at the perspectives of the anti-IDists. Most journals, when someone's idea is specifically being attacked, take the courtesy to alllow that person to respond, but so far that courtesy has not extended to IDists.
Nonetheless, it is interesting that ID has actually moved up the scale to the point where the journals realize that they have to grapple with these subjects at least a little bit.
One example is the Journal of Eukaryotic Microbiology which recently published the paper, "Using Protistan Examples to Dispel the Myths of Intelligent Design". The paper basically argues against Meyer's use of the Cambrian explosion as a launchpad for ID-based criticism of Darwinian evolution, and Behe's use of chloroquine-resistance for setting the limits of Darwinian evolution.
While the paper brings out several good points, the fact that the problems pointed out were so few and much to the side of the issue is contrasted with the name-calling they engage in, saying that Behe "demonstrates extraordinarily bad scholarship".
Let me make this clear - NO MATTER WHAT YOUR POSITION IS, BEING WRONG IS NOT EQUIVALENT WITH BAD SCHOLARSHIP. And there is NOWHERE in the paper where they level any charge against Behe which would be considered bad scholarship. They showed that there was a paper contraindicative of his findings that was published two years before his book. So what? People miss papers all the time, some of theme intentionally so because they are bad. Sometimes accidentally, considering the massive numbers of papers published every day. Simply leaving out a paper and disagreeing with people is not bad scholarship. Nor is publishing in books when a journal won't give you a fair hearing. In addition, they characterized Behe's detailed responses to criticism as "brushing them off". There is such a thing as a brush-off response. Behe's "Waiting Longer for Two Mutations" is no such thing.
It's pretty sad that, rather than arguing over the general thesis of Behe's work - that transformations which require multiple simultaneous amino acid changes are nearly impossible by Darwinian mechanisms - they instead argue over whether chloroquine requires multiple simultaneous mutations. This is missing the forrest because of the trees. If their point was to criticize chloroquine-resistance as a base reference for the limits of evolvability, it was a decent paper. If their point was, instead, to show that the ID project itself is misguided, they showed nothing of the sort. The fact that they engaged in such namecalling throughout the paper simply made the paper a sad reflection on the state of science today.
The paper deals with other ideas as well, and possibly I will have time later to get into them.