Creationists and Intelligent Designists have long pointed to bats as problems for evolution, because of the general lack of transitional fossils.
Here’s a sample of such an argument from the dean of young-earth creationists, Duane Gish of the Institute for Creation Research:
Bats (of the order Chiroptera), the only flying mammal, are especially interesting. Evolutionists assume, of course, that bats must have evolved from a non-flying mammal. There is not one shred of evidence in the fossil record, however, to support such speculations, for, as Romer says, “Bats appear full fledged in both hemispheres in the Middle Eocene . . .”
And here’s an example from the dean of ID, Phillip Johnson:
It isn’t merely that grand-scale Darwinism can’t be confirmed. The evidence is positively against the theory. For example, if Darwinism is true then the bat, monkey, pig, seal, and whale all evolved in gradual adaptive stages from a primitive rodent-like predecessor. This hypothetical common ancestor must have been connected to its diverse descendants by long linking chains of transitional intermediates which in turn put out innumerable side branches. The intermediate links would have to be adaptively superior to their predecessors, and be in the process of developing the complex integrated organs required for aquatic life, flight, and so on. Fossil evidence that anything of the sort happened is thoroughly missing and in addition it is extremely difficult to imagine how the hypothetical intermediate steps could have been adaptive.
And here’s another from Johnson:
Perhaps one day scientists will be able to test some macroevolutionary mechanism, involving changes in the rate genes or whatever, that will explain how a four-footed mammal can become a whale or a bat without going through impossible intermediate steps. The difficulties should be honestly acknowledged, however.
I’m pleased to report that that “one day” has arrived.
The New Scientist reports on Nov., 13th, 2004, in an article titled Rogue finger gene got bats airborne, that
A change to a single gene allowed bats to grow wings and take to the air, a development that may explain why bats appeared so suddenly in the fossil record some 50 million years ago.
Bats have been an evolutionary enigma. That’s because the oldest fossil bats look remarkably like modern ones, each having wings formed from membranes stretched between long fingers, and ear structures designed for echolocation. No fossils of an animal intermediate between bats and their non-flying mammal ancestors have been found.
Now Karen Sears, at the University of Colorado Health Sciences Center in Denver, has discovered why intermediate forms may be missing in the fossil record. In a bid to understand where bats’ specialised finger digits evolved from, Sears compared their embryological development with that of the finger digits of mice. … Sears believes that bats began to evolve when this one gene became activated. Although it is a small developmental change, if it allowed the ancestors of bats to grow extended digits it could explain how bats evolved flight so rapidly, Sears told the Society of Vertebrate Paleontology meeting in Denver. Relatively few transitional forms would have existed just briefly before being displaced by more advanced forms.
Here’s my prediction: the ID community will be strangely silent about this new discovery.
Here’s more on this story from SciScoop: http://www.sciscoop.com/story/2004/11/11/82718/510