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elfsI had the pleasure recently of watching the PBS Nova episode Judgement Day: Intelligent Design on Trial. The show was quite good. If you google for it, you'll find a lot of complaints about it, most of which whine that it was "biased in favor of evolution" and "didn't show the science behind ID."
Well, there's a reason for that: there is no science behind ID, and reality itself is biased in favor of evolution.
One of the things that annoyed me was the explanation of Tiktaalik. In 1999, paleontologists discovered a plain in Northern Canada that exposed a rock bed, the best date of which was exactly between the era of the fish and the emergence of the amphibians. Evolutionary theory predicted that in that rock bed one might find a transitional fossil: something with characteristics of both a fish and an amphibian.
It took four years, but they did find something like that: Tiktaalik, a fish with hefty fins allowing for motility on muddy surfaces but, more importantly, a broad head with forward-pointing eyes, very un-fish-like. The explanation for why Tiktaalik was an excellent "transitional fossil" between fish and amphibian was quite solid.
And yet, something important was missing from the discussion of Tiktaalik. Something vital.
One of the most common statements you hear from the "intelligent design" side of the argument is that, to quote Of Pandas and People, "Intelligent Design means that various forms of life began abruptly - through an intelligent agency, with their distinctive features already intact-- fish with fins and scales, birds with feathers, beaks, and wings, etc." A bizarre result of this is that the Intelligent Design yahoos, the useful idiots at the bottom of the ID intellectual foodchain, frequently write screeds (both in small-town punditocracies as well as simple letters to the editor) asking of what use is half a wing, or the partial evolution of a feather?
With questions like this, the ID people attempt to argue that there's no such thing as a "transitional" fossil form. You can't have a species halfway between a dinosaur and a bird, because, to quote from that same atrocious article I linked to above, "Imagine such a species surviving in such a miserable state over many millions of years waiting for fully-formed wings to evolve."
Tiktaalik is important not because it's a transitional form, but because it's a highly successful organism in its own right. By having a more robust undercarriage, and by having both eyes in the front, it was significantly more capable as a large organism of dragging itself to niches that prior to its emergence had probably only ever been visited by insects. The front-mounted eyes suggested that, although it had not left its icthyian nature completely behind, it was already preying upon insects its more fish-like ancestors could never have reached, and avoiding predators that were preying upon its ancestors.
Tiktaalik wasn't busy waiting for fully-formed legs to evolve. And it wasn't "miserable." (That's a value judgement, by the way. Nature Doesn't Care what we think about its day-to-day operation.) Tiktaalik ancestors didn't hope to someday have legs. Some of Tiktaalik's ancestors had stronger fins than others, and those that did found it advantageous to pull themselves up into the mud and snag a few tasty bugs. They lived longer; they had more children; stronger fins were selected. The same with the eyes; those with eyes a millimeter closer to the front found binocular vision advantageous in snagging said tasty bugs. That characteristic was selected for. Nature doesn't "want" or "wait" for these things; they happen as a consequence of living things doing what living things do within a constantly changing environment like our Earth.
While Tiktaalik happened, other fish remained in the sea, eating and breeding and following their own reproductively successful strategies. Tiktaalik found a new way to exploit a new niche. It didn't crowd out an old niche; it didn't supersede the other fishes. (Another popular whine among Creationists is "If man evolved from apes, why are there still apes?" The common and excused answer is that we didn't want the apes' niche. The horrific and true answer is that we do want their niche, we're just not done killing them all off. Evolution, even the "bad" aspects of it (again, note that's a human value judgement and Nature Doesn't Care), takes time.)
I would really have liked Nova to mention Tiktaalik's existence as a highly successful organism optimized for a specialized niche in its time and place. Tiktaalik's existence points out the vicious deception of two of the the Cdesign Proponentsists's favorite stupidities, and it would have been nice to have a biologist put the screws to ID's thumbs even harder.
Well, there's a reason for that: there is no science behind ID, and reality itself is biased in favor of evolution.
One of the things that annoyed me was the explanation of Tiktaalik. In 1999, paleontologists discovered a plain in Northern Canada that exposed a rock bed, the best date of which was exactly between the era of the fish and the emergence of the amphibians. Evolutionary theory predicted that in that rock bed one might find a transitional fossil: something with characteristics of both a fish and an amphibian.
It took four years, but they did find something like that: Tiktaalik, a fish with hefty fins allowing for motility on muddy surfaces but, more importantly, a broad head with forward-pointing eyes, very un-fish-like. The explanation for why Tiktaalik was an excellent "transitional fossil" between fish and amphibian was quite solid.
And yet, something important was missing from the discussion of Tiktaalik. Something vital.
One of the most common statements you hear from the "intelligent design" side of the argument is that, to quote Of Pandas and People, "Intelligent Design means that various forms of life began abruptly - through an intelligent agency, with their distinctive features already intact-- fish with fins and scales, birds with feathers, beaks, and wings, etc." A bizarre result of this is that the Intelligent Design yahoos, the useful idiots at the bottom of the ID intellectual foodchain, frequently write screeds (both in small-town punditocracies as well as simple letters to the editor) asking of what use is half a wing, or the partial evolution of a feather?
With questions like this, the ID people attempt to argue that there's no such thing as a "transitional" fossil form. You can't have a species halfway between a dinosaur and a bird, because, to quote from that same atrocious article I linked to above, "Imagine such a species surviving in such a miserable state over many millions of years waiting for fully-formed wings to evolve."
Tiktaalik is important not because it's a transitional form, but because it's a highly successful organism in its own right. By having a more robust undercarriage, and by having both eyes in the front, it was significantly more capable as a large organism of dragging itself to niches that prior to its emergence had probably only ever been visited by insects. The front-mounted eyes suggested that, although it had not left its icthyian nature completely behind, it was already preying upon insects its more fish-like ancestors could never have reached, and avoiding predators that were preying upon its ancestors.
Tiktaalik wasn't busy waiting for fully-formed legs to evolve. And it wasn't "miserable." (That's a value judgement, by the way. Nature Doesn't Care what we think about its day-to-day operation.) Tiktaalik ancestors didn't hope to someday have legs. Some of Tiktaalik's ancestors had stronger fins than others, and those that did found it advantageous to pull themselves up into the mud and snag a few tasty bugs. They lived longer; they had more children; stronger fins were selected. The same with the eyes; those with eyes a millimeter closer to the front found binocular vision advantageous in snagging said tasty bugs. That characteristic was selected for. Nature doesn't "want" or "wait" for these things; they happen as a consequence of living things doing what living things do within a constantly changing environment like our Earth.
While Tiktaalik happened, other fish remained in the sea, eating and breeding and following their own reproductively successful strategies. Tiktaalik found a new way to exploit a new niche. It didn't crowd out an old niche; it didn't supersede the other fishes. (Another popular whine among Creationists is "If man evolved from apes, why are there still apes?" The common and excused answer is that we didn't want the apes' niche. The horrific and true answer is that we do want their niche, we're just not done killing them all off. Evolution, even the "bad" aspects of it (again, note that's a human value judgement and Nature Doesn't Care), takes time.)
I would really have liked Nova to mention Tiktaalik's existence as a highly successful organism optimized for a specialized niche in its time and place. Tiktaalik's existence points out the vicious deception of two of the the Cdesign Proponentsists's favorite stupidities, and it would have been nice to have a biologist put the screws to ID's thumbs even harder.
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no subject
Date: 2007-11-21 05:30 pm (UTC)While I have to agree with you that it would have been nice for Nova to point out that Tiktaalik was a successful species and not just a transitional form -- it would have distracted from the argument Nova was presenting about the teaching of evolution and ID/creationism (the point, in my opinion, being "ID says there aren't these transitional forms, but here's a very good one!")
Still - it was a great show, and in a way, I hope Nova can do a special solely on these "transitional" fossils or something similar to show that they are indeed righteous species in their own way, not just merely stepping stones....
no subject
Date: 2007-11-21 06:21 pm (UTC)All it would have taken to satisfy me is to proceed this triumphal note with something like "Not only does Tiktaalik have characteristics of both a fish and an amphibian, but it was a very successful animal in its own right. Creationists often ask, what good is half a leg, or half a wing? Well, here we have an animal with half a leg, and in some sense half a head, and yet it was a very successful predator for its time."
The same thing could have been achieved again during the Miller sequence explaining why genetics validated evolutionary theory. During the segment where the tree of life was shown, the implication was always that the tree was based on morphology. A very brief segue showing how genetics confirmed the correlation between the morphological tree and the genetic tree would have much more solidly driven down the nails on ID's coffin.