Evolution has given humans countless unique features, but one body part stands out as an unsolved puzzle: the human chin. While scientists can often trace the development of various organs and ...

Throughout most of human history, evolution progressed slowly. Small genetic changes took thousands of years to permeate populations. Natural selection was intentional, reactive, and gradual. However, ...

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 ...