This is this forum to a tee.
While we may speculate about the details, the existence of transitional fossils—and the evolution of birds from reptiles—is fact.
Yet, when you ask for evidence to support the "fact" it never eventuates.
For the Birds
Coyne makes general claims that the evolution of dinosaurs to birds, and the origin of flight, is well documented in the fossil record. But when he gets to specifics, he just makes excuses for why they don’t really know anything at all about the evolution of birds.
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Because reptiles appear in the fossil record before birds, we can guess that the common ancestor of birds and reptiles was an ancient reptile, and would have looked like one. We now know that this common ancestor was a dinosaur. 9 [italics his]
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Coyne so easily goes from “guess” to “know.”
Even if the fossil record showed that a particular reptile died before a particular bird, it doesn’t prove that the bird is a biological descendant of the reptile. It is an indisputable fact that Big Brown (the horse that won the 2008 Kentucky Derby) died in 2008, and President George Washington died in 1799. Does that prove that Big Brown was a biological descendant of George Washington? Of course not!
We want you to get the full impact of Coyne’s explanation about bird evolution, so here is a long passage. As always, colored highlights are ours, but the italics for emphasis in the quote are his.
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But if feathers didn’t arise as adaptations for flying, what on earth were they for? Again, we don’t know. They could have been used for ornamentation or display—perhaps to attract mates. It seems more likely, though, that they were used for insulation. Unlike modern reptiles, theropods may have been partially warm-blooded; and even if they weren’t, feathers would have helped maintain body temperature. And what feathers evolved from is even more mysterious. The best guess is that they derive from the same cells that give rise to reptilian scales, but not everyone agrees.
Despite the unknowns, we can make some guesses about how natural selection fashioned modern birds. Early carnivorous dinosaurs evolved longer forelimbs and hands, which probably helped them grab and handle their prey. That kind of grabbing would favor evolution of muscles that would quickly extend the front legs and pull them inward: exactly the motion used for the downward stroke in true flight. Then followed the feathery covering, probably for insulation. Given these innovations, there are at least two ways flight could have evolved. The first is called the “trees down” scenario. There is evidence that some theropods lived at least partly in trees. Feathery forelimbs would help these reptiles glide from tree to tree, or from tree to ground, which would help them escape predators, find food more readily, or cushion their falls.
A different—and more likely—scenario is called the “ground up” theory, which sees flight evolving as an outgrowth of open-armed runs and leaps that feathered dinosaurs might have made to catch their prey. Longer wings could also have evolved as running aids. The chukar partridge, a game bird studied by Kenneth Dial at the University of Montana, represents a living example of this step. These partridges almost never fly, and flap their wings mainly to help them run uphill. The flapping gives them not only extra propulsion, but also more traction against the ground. Newborn chicks can run up 45-degree slopes, and adults can ascent 105-degree slopes—overhangs more than vertical!—solely by running and flapping their wings. The obvious advantage is that uphill scrambling helps these birds escape predators. The next step in evolving flight would be very short airborne hops, like those made by turkeys and quail fleeing from danger.
In either the “trees down” or “ground up” scenario, natural selection could begin to favor individuals who could fly farther instead of merely gliding, leaping, or flying for short bursts. Then would come the other innovations shared by modern birds, including hollow bones for lightness and that large breastbone.
While we may speculate about the details, the existence of transitional fossils—and the evolution of birds from reptiles—is fact. 10
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The only real science here is the study showing that wings can help birds run uphill. All the rest is, as Coyne admits, speculation—and therefore an undeniable fact!
We don’t have space this month to point out all the times Coyne makes bold general claims about the fossils, and then makes excuses for why the fossil data doesn’t support the general claim. We hope we have given you enough examples to prove our point, and hope that you
read his book to find more examples for yourself.
http://scienceagainstevolution.info/v13i8f.htm
