Human testicles are much smaller, in proportion, to some of our primate cousins. Evolution can tell us why. But the size of ...

If we look across the whole of the mammal branch of the tree of life, we find there are many groups of mammals that have ...

The Caldwell Zoo announced Tuesday they have three brand new additions to their animal family. ‘The obvious choice’: ...

A male colobus monkey competes ferociously for access to a harem of females who will mate exclusively with him. Macaques, on the other hand, live in peaceful mixed troops of about 30 monkeys and have ...

But perhaps the most plausible explanation relates to the way they mate. A male colobus monkey competes ferociously for access to a harem of females who will mate exclusively with him.