Robert M. Yerkes was assistant professor of comparative psychology at Harvard University, managing editor of the Journal of Animal Behavior, and editor of the Animal Behavior Series.
A nation is deļ¬ned by what it preserves.
The way they live, the food they eat, and the effect on us
A true but unlikely tale
Story and Photographs by William Rowan
Increasing day length on the early Earth boosted oxygen released by photosynthetic cyanobacteria.