Evolution of Body Mass in Bats: Insights from a Large Supermatrix Phylogeny

MOYERS ARÉVALO, REYNA LETICIA; AMADOR, LUCILA I.; ALMEIDA, FRANCISCA C.; GIANNINI, NORBERTO P.

JOURNAL OF MAMMALIAN EVOLUTION

SPRINGER

Año: 2018

1064-7554

Bats are atypical small mammals. Size is crucial for bats because it affects most aerodynamic variables and several keyecholocation parameters. In turn, scaling relationships of both flight and echolocation have been suggested to constrain bat bodysize evolution. Previous studies have found a large phylogenetic effect and the inclusion of early Eocene fossil bats contributed torecover idiosyncratic body size change patterns in bats. Here, we test these previous hypotheses of bat body size evolution using alarge, comprehensive supermatrix phylogeny (+800 taxa) to optimize body size and examine changes reconstructed alongbranches. Our analysis provides evidence of rapid stem phyletic nanism, an ancestral value stabilized at 12 g for crown-cladeChiroptera followed by backbone stasis, low-magnitude changes inside established families, and massive body size increase ataccelerated rate in pteropodid subclades. Total variation amount explained by pteropodid subclades was 86.3%, with mostchanges reconstructed as phyletic increases but also apomorphic decreases. We evaluate these macroevolutionary patterns inlight of the constraints hypothesis, and in terms of both neutral and adaptive evolutionary models. The reconstructed macroevolutionof bat body size led us to propose that echolocation and flight work as successive, nested constraints limiting bat evolutionalong the body size scale.