The Mütter Museum’s contribution to The Philadelphia Year of Evolution celebrating the two-hundredth anniversary of Charles Darwin’s birth was the exhibit The Evolution of Birth. It explored physiological changes that occurred while early humans transitioned from quadrupeds to bipeds. As humans evolved into being able to walk on two feet, the width of the birth canal was reduced. These anatomical changes meant that a human woman usually required the assistance of another person in order to more safely give birth.