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 ...

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 ...

There are different reasons why one testicle may appear bigger than the other. If one of your testicles is slightly bigger than the other, don’t panic, this is completely normal for most men and boys.