Snakes have lost the gene that encodes ghrelin, a hormone that helps regulate hunger in many vertebrates, according to a new study.

Thirteen million years ago, a group of medium-sized monkeys known for guarding their territory among the treetops with fearsome "howls" started doing something new. These monkeys, among the oldest ...

For decades, ecologists have known that how a species looks or eats affects its environment. But a new study by researchers at the University of California, Santa Cruz, shows that social behavior ...