I’m in Austin, Texas this weekend, hanging out with Matt Dillahunty and Beth Presswood, and it’s bats, bats, bats all day long. I’m giving a talk about bat evolution this afternoon (theme: so what if there aren’t many fossils?), and then we’re going on a bat cruise to watch the swarm of Mexican (don’t tell the Republicans) Free Tailed Bats launch themselves into the twilight skies. Also, somewhere in there will be Texas barbecue. I don’t think that will have much bat in it.
While I’m distracted, watch the pretty bats fly.
Last I heard (mammology class many, many moons ago), there were hypotheses that two lines of bats had evolved independently giving us micro and macrochiroptera. What are the current thoughts on that?
IIRC, it’s a fringe theory along the lines of aquatic apes.
That was a 90s sort of thing — it prompted a whole bunch of follow up studies that basically concluded that the megabats and microbats were monophyletic. So no, forget that.
The new heresy is Yangochiroptera vs. Yinpterochiroptera, the idea that there are some families classified as microbats that are actually more closely related to the megabats — the molecular phylogenies don’t line up perfectly with the morphological taxonomies. I’m not going to weigh in on that, though — I don’t know enough about the evidence to be able to judge.
Yang and Yin?
Biologist are a fun bunch.
☯
Were you there when they made the barbeque? If not you have no way of knowing what’s in it./Ken H. off
Yes, biollmeans.
I’m going to be at the cruise yaaay! But the bats might not come out because it’s wet and rainy.
The only close encounter I’ve had with a bat was when one flew into my bedroom. I didn’t learn much about bats from the experience, but I did learn that I am capable of dropping into a G.I. Joe-style belly crawl when stressed.
Nice example of convergent evolution there, with the bat picking the moth off the water with its back legs just like an eagle catching a fish!
Bats and barbecue are a winning combination, but it’s really hard to go wrong in Austin.
The current Smithsonian mag (Oct. 2013, p. 18) has an item about a moth that ‘jams’ a bat’s sonar:
The article notes that other moths, toxic to bats, use clicks to warn them off, but not to jam their signal.
Cool.
Microbats are most of the bat species: small, nocturnal, insect-eating, echolocating. Megabats are the remaining: big, diurnal, fruit-eating, with well-developed vision.
Here is the controversy: did microbats and megabats evolve into battishness separately? Or did megabats evolve from some species of microbats?
Molecular-phylogeny methods have been able to resolve phylogeny issues that have been long-running controversies, but they also have problems, like composition bias, reversals, repeated evolution, lineage sorting, lateral gene transfer, and just plain old statistics. Ideally, one would want to compare several genes from several species, but that has not always been very feasible, especially in the past.
So there have been plenty of molecular-phylogeny controversies. The worst of them has been the overall phylogeny of eukaryotes. From small-subunit ribosomal-RNA molecules, often used in long-distance phylogeny, one could find that eukaryotes’ phylogeny was a crown group of animals, plants, and fungi, with a lot of protists branching off before them. But in the 1990’s, it was discovered to be inconsistent with phylogenies from proteins, and that long branching causes trouble. The phylogeny that then emerged seems to be stable, however. Animals and fungi are relatively close together, but plants are as distant from them as most other eukaryotes.
One thing that’s been helping is improved gene-sequencing technology. So it may be feasible to sequence 100 genes from 100 species of bats, for instance, without breaking a lab’s budget. So we may see a solution before long.