Given the diversity of social taxa, why do some species form complex societies, while other closely related species do not? Within these societies, why do some individuals attempt to reproduce ...

They are as distinct as though they were two separate species. Yet the entire complex of populations belongs to a single taxonomic species, Ensatina escholtzii. Ring species, says biologist David ...

The pallium is the brain region where the neocortex forms in mammals, the part responsible for cognitive and complex functions that most distinguishes humans from other species. The pallium has tradit ...