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 evolved testicles of all different sizes. In almost all these separate cases, ...

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 ...

We humans, for example, were animals before we became vertebrates; mammals before evolving into primates and so on. The groups of species we share each of these branches with reveal the order our body ...

A body and a gut (inventions of the animal branch) must have come before backbone and limbs (vertebrate branch); milk and hair (mammals) came before fingernails (primates).

The human body is a machine whose many parts – from the microscopic details of our cells to our limbs, eyes, liver and brain – have been assembled in fits and starts over the four billion years of our ...

A body and a gut (inventions of the animal branch) must have come before backbone and limbs (vertebrate branch); milk and hair (mammals) came before fingernails (primates). The story of evolution ...

A body and a gut (inventions of the animal branch) must have come before backbone and limbs (vertebrate branch); milk and hair (mammals) came before fingernails (primates).

The human body is a machine whose many parts – from the microscopic details of our cells to our limbs, eyes, liver and brain – have been assembled in fits and starts over the four billion ...