Blue Collar Scientist

Intelligent Design Creationists have said for some time that bats pose a problem for evolutionary theory.

Things are even tougher for the evolutionist with the knowledge that the ‘oldest known’ complete fossils of bats … show indications of a fully-developed echolocation system.

Evolutionary theory predicts that in such cases, transitional forms did exist, and are possibly waiting to be discovered in the fossil record. And today, Carl Zimmer reports on his blog about a newly discovered bat fossil.

The ear bones in its head don’t have the distinctive shape found in living bats that echolocate, suggesting that it had to rely on sight and sound to catch prey–insects, judging from its teeth. Flight evolved first in bats … and echolocation only came later.

Oh. That must really suck to be an intelligent design creationist who thinks that bats popped out of nowhere with echolocation fully developed, then.

It turns out this bat fossil is the most primitive bat ever found, and it has several other transitional attributes:

1. Evolutionary theory predicts that early bats would have body proportions similar to that of the walking mammals from which bats evolved. This fossil has shorter arms, and longer legs, than modern bats. Prediction fulfilled!
2. Almost all modern bats have only a single claw. Evolutionary theory predicts that early bats should have a full compliment of claws, and that bats who lived in between these times should show a gradual loss of claws. Many bat fossils are single-clawed with vestigial claws on other fingers, thus fulfilling the prediction as far as was able. But this bat completes things - it has claws on all five fingers, just like evolution predicts.
3. Evolutionary theory predicts that as a lineage evolves flight, early fliers will be less strong, less powerful flyers than later ones. Some evolutionary biologists have also hypothesized that powered flight most likely evolved from early gliding. Most modern bats fly with a full-time power stroke, flapping their wings continually during flight. But this fossil’s wings suggest that it alternated between flapping and gliding. Prediction fulfilled!

This is just a summary - go read Carl’s story. It’s outstanding, and it has pictures.