Well, there are several possibilities that account for the evolution of ugly bats. I wonder what Coyne says ....?
Leaf-nosed bats are found in both the New and Old World, and the New World ones are the most numerous group in the order Chiroptera (bats), which itself is one of the most diverse order of mammals, second only to rodents (40% of mammal species are rodents; 20% are bats). A probably aprocryphal story relates evolutionist J. B. S. Haldane’s answer when asked what one could infer about the Creator from surveying his creation. ”An inordinate fondness for beetles,” Haldane supposedly said. (Of the roughly 1.7 million described species on Earth, 300,000-400,000 are in the order Coleoptera—beetles.) If that question were asked about mammals, one could reply that God showed an inordinate fondness for rodents and bats, and a notable distaste for primates.Why should we assume that the ugliness is a byproduct of natural selection? Lot's of humans are ugly, is that also a byproduct of natural selection? :-)
The function of the “leaf” isn’t fully known, but it’s suspected to be important in receiving the echolocation signals emitted by bats.
You may find this beast ugly, but that’s speciesism! I find all animals beautiful because they’re products of evolution, embodying all the mechanisms that drive the process. The ugliness, in this case, is probably a byproduct of natural selection.
Seriously, we don't know why these bats have such faces. Why couldn't it just be an accident of evolution? I'm not saying that this is necessarily true. What I AM saying is that it's wrong to just ASSUME, without evidence, that such an appearance is probably due to natural selection. I bet I would get lots of flak if I said that it was probably due to random genetic drift.