The potential functional consequences of mandible shape evolution in giant house mice from Gough Island

Abstract

An extremely large-bodied Mus musculus domesticus mouse population from the remote Gough Island (GI) were used to study how the evolution of shape may affect the performance of a morphological trait. The study question asked was how GI mice divergence in mandibular shape from a mainland strain (WSB) might have affected their jaw performance. It was found that GI mice display significantly greater maximum bite force after correcting for body weight and jaw length than WSB. However, GI mice show no significant difference in relative maximum gape compared to WSB. Morphological comparisons among strains suggest relative increases in mandibular corpus depth and symphysis length may play a role in the evolution of increased relative bite force in Gough Island mice.