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Re: Origin of flight in birds and bats
> Wouldn't that suggest that frugivorous megabats, with good eyesight
> and no echolocation, evolved from insectivorous cave-dwelling
> microbats with (presumably) small eyes and echolocatory abilities?
> Surely that would require a lot of reversals in the megabats -
> unless flapping flight evolved twice in bats.
The microbats are already paraphyletic with respect to the megabats.
That hasn't been doubted for years: the molecular evidence is clear-cut,
and the morphological evidence doesn't contradict it much. Plus, all
known stem-bats all the way to *Onychonycteris* and probably beyond are
microbats in terms of size and ecology.
Why couldn't the flightless stem-bats have been arboreal rather than
cave-dwelling? Dropping is presumably similar in both cases.
I suppose the idea is that echolocation is necessary in caves but not an
obvious idea elsewhere. The only echolocating birds spend a lot of time