quote:
About the strongest evidence they have is genetic, but since it is relatively new, we will see how it holds up over time.
RA Fisher, 1930, "The Genetical Theory of Natural Selection"
This book is probably the single-most important work after Origin, and is considered to be the origin of the modern synthesis. I find it curious that 75 years is considered relatively new. I recognize that Rand probably is thinking that sequencing is the only genetic evidence there is and that is relatively new. That is why you shouldn't rely on tracts and Dr. Dino for your science info, they sometimes leave out important stuff.
Now back to the topic. I think the whale lineage is especially good despite not "having the dots connected" because it is an example of how multiple lines of evidence reinforce each other. I cannot see how this could happen unless the lineage evolved as stated. I know this has been stated over and over again on this forum, but maybe you (Rand & Christian) missed it. Here is a gross simplification of what I mean.
Long before any DNA evidence it was known that some early whale skulls had shared components with a group of artiodactyls (even-hoofed mammals). From this bit of evidence it was speculated (read PREDICTED) that whales evolved as an early offshoot from the artiodactyls. It is like reaching into a 1000-piece jigsaw puzzle and pulling out a single piece. If that piece is light blue you might speculate that the puzzle is a landscape with a sky, even without any idea of what the puzzle is supposed to be. From a single line of evidence it was predicted that the earliest whales would look like these artios (called mesonychids) and later whales less so and more like modern whales. That is a bold prediction. A single whale fossil with elephant-like or rodent-like traits would demolish the hypothesis. As it turns out every single fossil found has been as expected (more or less, what is important is that no fossil has contradicted this prediction). Furthermore it was found that some creatures thought to be mesonychids had ears that were indisputably whale-like. Like any good hypothesis, there is room for growth. Now, as I undertstand it, mesonychids look like the ancestor of whales because both are derived from the same early artiodactyl stock (they are close cousins) not because mesonychids are the actual ancestral group. But the prediction still holds true.
A potential argument against the above lines of evidence is that there is the possibility that there is a bias. That is, if one 'knows' that whales evolved from artiodactyls, then one might unintentionally focus on those traits and might miss others. This is where peer review is important. I do not believe that at any time there was a 100% consensus that whales are allied to artiodactyls. Evidence is reviewed by both supporters and detracters of your theory. Science does not work by a single individual (or team) making an assertion that is just believed by everyone. The fossil evidence for the artiodactyl origin of whales has passed peer review repeatedly over the last few decades.
Finally, the DNA evidence. This is of critical importance. DNA sequences are pretty much immune to biases, short of faking the sequences (which would be academic suicide). The fact is that the DNA evidence supports repeatedly the relationship between artiodactyls and whales. Had the DNA evidence come first, then the fossils, someone might ask if the fossil evidence was misinterpreted to match the DNA. But the DNA evidence came after and is completely consistent with the predictions made by the fossils. Again, if it were only a small DNA sequence that showed this the argument could be made that it was an amazing coincidence. But the fact remains that it is multiple sequences across many genes that say the same thing. And this has happened over and over across taxa. Looking only at DNA and without a single fossil the evolutionary tree looks pretty much exactly the way it does based on fossils. The odds of this are statistically impossible if it is supposed to be just coincidence.
Doctor Bashir: "Of all the stories you told me, which were true and which weren't?"
Elim Garak: "My dear Doctor, they're all true"
Doctor Bashir: "Even the lies?"
Elim Garak: "Especially the lies"
™ Version 4.2
