Conservatism and Adaptability during Squirrel Radiation: What Is Mandible Shape Telling Us?

摘要: Both functional adaptation and phylogeny shape the morphology of taxa within clades. Herein we explore these two factors in an integrated way by analyzing size variation mandible extant squirrels using landmark-based geometric morphometrics combination with a comparative phylogenetic analysis. Dietary specialization locomotion were found to be reliable predictors shape, prediction probably reflecting underlying diet. In addition weak but significant allometric effect could demonstrated. Our results strong signal family as whole well main clades, which is agreement general notion being conservative group. This fact does not preclude explanations for rather indicates that ancient adaptations kept prominent role, most genera having diverged little from their ancestral clade morphologies. Nevertheless, certain groups have evolved conspicuous allow them specialize on unique dietary resources. Such mostly occurred Callosciurinae reflect radiation into numerous ecological niches tropical subtropical forests Southeastern Asia. reconstruction oldest known fossil (Eocene, 36 million years ago) show nuts seeds, implying development protrogomorphous sciuromorphous skulls was necessarily related change