A complex genetic architecture underlies mandibular evolution in big mice from Gough Island

Research reveals that the evolution of large mandibles in Gough Island mice is driven by a complex genetic architecture, with multiple quantitative trait loci (QTL) contributing to mandibular shape and size. Unlike mainland mice, these island-dwelling rodents exhibit significant divergence in traits like temporalis lever arm length and condyle length, which influence jaw function. While most QTL effects are additive and dispersed, some, particularly those linked to body size, suggest directional selection may have played a role in the evolution of larger mandibles, possibly as a correlated response to overall body growth.

Parmenter, M. D., Nelson, J. P., Gray, M. M., Weigel, S., Vinyard, C. J., & Payseur, B. A. (2022). A complex genetic architecture underlies mandibular evolution in big mice from Gough Island. Genetics, 220(4). https://doi.org/10.1093/genetics/iyac023