Bats show diverse mutations in "language gene"
As I've mentioned before, some of my activities as a research assistant have involved various field biology surveys of bats. Despite their bad reputations, they really are amazing to work with, I am absolutely in awe about everything about them, they are so incredibly specialized in so many ways. They are great examples of adaptive radiation, you can find them on every continent except Antarctica, and with around 1100 species they make up about 20% of all mammal species. They are also a ton of fun to work with, it's really interesting to observe how much temperament varies between different species.
So, on the newswire today, new insights into a possible way to use genetics to trace variation in echolocation calls. The study is freely available courtsey of PLoS, highly recommended reading!
First for a little bit of background, a while back researchers identified a gene called FOXP2 that appears to play a role in the development of language skills. The human and chimpanzee versions of the gene differ by only two mutations, leading to much speculation that those mutations were the keys that opened the door to complex language for our distant ancestors.
FOXP2 was thought to be highly conserved among vertebrates, supporting the fact that those two mutations in humans could be so crucial, but further research has shown that isn't necessarily the case: the new paper shows that bats have a diverse set of mutations in the gene. Snipped from the abstract:
We found that contrary to previous reports, FoxP2 is not highly conserved across all nonhuman mammals but is extremely diverse in echolocating bats. We detected divergent selection (a change in selective pressure) at FoxP2 between bats with contrasting sonar systems, suggesting the intriguing possibility of a role for FoxP2 in the evolution and development of echolocation. We speculate that observed accelerated evolution of FoxP2 in bats supports a previously proposed function in sensorimotor coordination.
This is cool for several reasons:
1) A gene we thought was highly conserved is actually highly divergent, within one taxa at least.
2) Said gene might have a new function (sensorimotor) besides the one originally attributed to it (verbal language).
3) This could give us clues to develop a more detailed picture of the evolution of bats. They are regrettably scanty in the fossil record, and if this could help develop a clearer picture of their divergence patterns, it will be really fascinating.
4) If it is this divergent in bats, what about other taxa that haven't been studied yet. The paper mentions that they didn't find the same levels of divergence in dolphins, which also echolocate, but I'm sure there are many other species worth studying in terms of FOXP2 traits. Up until now FOXP2 research has been a little anthropocentric, focused on how we differ from our closest relatives, maybe this study will be a gateway to research on a broader sample of vertebrates. What about birds, they're highly vocal, what patterns do their FOXP2 genes show?
5) Have I mentioned that bats are just plain amazing?