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, ...

An ambitious plan to map all 37 trillion cells in the human body is transforming understanding of how our bodies work, scientists report. The received wisdom said we were built from around 200 types ...

Human testicles are much smaller, in proportion, to some of our primate cousins. Evolution can tell us why. But the size of other body parts is a little bit more of a mystery. The human body is a ...

Pain sends a signal that the body needs protection and healing. However, if the physiological changes triggered by pain persist, harm will ensue, and acute pain may become chronic, so pain must be ...