6. Palmaris muscle
This long narrow muscle runs from the elbow to the wrist and is missing in 11% of humans today. Once important for hanging and climbing, you probably would prefer to keep it if you were a martial artist or rock climber.
7. Male nipples
Both men and women have nipples because, in the early stages of fetal development, an unborn child is effectively sexless (without gender). Thus, nipples are present in both males and females. Men generally lack the necessary levels of prolactin to stimulate lactation and cannot produce milk.