On the origins of bat flight and implications

• Illustration from Anderson et al 2020

So a new interesting study has come out on the origins of bat flight. In it we have an examination of the various hypotheses of how bats became volant, with a very intriguiging possibility that flight might have evolved independently at least three times within Chiroptera. Besides this admitely headline stealing possibility some other considerations on the mechanics of bat flight have also been dished, including speculation on the reason for bat size limits (mammalian tidal breathing not being as efficient as the archosaurian airsac driven one) and the ramifications of “mitten gliding” as opposed to the more typical patagia seen in most gliding mammals.

Suffice to say, this has incalculable value in my own research on volaticotheres. More broadly, however, this parallels recent studies on the origins of theropod flight, suggesting that dinosaurs might have acquired flight independently multiple times as well. This might very well paint a very distinct picture of flight in tetrapods: chiefly, that while broadly speaking it might be an extremely rare adaptation, flight almost invariably occurs multiple times within closely related lineages. Either this is because the specific ecological niche that these animals occupied is conductive to flight, or perhaps because aspects of these creatures’ biology makes flight acquisition easier. Given that both birds and bats display unique immune systems due to the energy requirement for powered flight, this latter possibility might be of particular interest.

Anyone doing speculative evolution projects, take note.