The common treeshrew (Tupaia glis) — a small mammal native to Thailand, Malaysia, and Indonesia — defies two widely tested rules that describe patterns of geographical variation within species: the island rule and Bergmann’s rule, according to a research team led by Yale University Professor Eric J. Sargis. The common treeshrew (Tupaia glis). Image credit: Benjamin Balazs. “There are a number of ecogeographical ‘rules’ that describe...
