Humans Were Losing This Bone — Now It’s Making A Rapid Return
Some people have an extra bone in their knee , known as afabella . No one has key a determination for it and it increases the risk of arthritis , so it ’s scarcely surprising it was becoming increasingly rare . Yet a field of human knees over the last century and a half has revealed the fabella is bouncing back at a pace too fast to be natural selection ....