Ears Variation
Darwin's tubercle
A small bump on the folded rim of the ear, which Darwin thought was the leftover tip of a pointed ancestral ear. Between 10% and 58% of people have one, depending on the population.
10–58% of people
Vestigial
A leftover from evolutionary ancestors.
7 oddities.
Spiritual 6Icky 4Not an emergency 20Get it checked 14Try it 62Learnable 20Party trick 19Vestigial 7Genetic 35Sleep 6Illusion 21Childhood 10Debunked myth 11Community 13Famous people 14Record 7
Ears Trick
Ear wiggling
Moving the outer ears using three small muscles that most mammals use to point their ears at sounds. Between 10% and 22% of people can wiggle at least one ear. Many more can learn.
10–22% (one ear)
Skin Reflex
Goosebumps
Tiny muscles at the base of every hair pull the hair upright when you are cold, scared, or moved. In a furry animal this traps warm air or makes it look bigger. In a human it does almost nothing.
Everyone
Organs Sound
Hiccups
A hiccup is a sudden jerk of the diaphragm followed by the voice box snapping shut. Everyone gets them, even before birth. The record case lasted 68 years.
Everyone
Bones Trick
Midtarsal break
A foot that bends in the middle, between the heel and the ball, as well as at the toes. About 1 in 13 people have it. It is a leftover from tree-climbing ancestors.
About 1 in 13 (7.7%)
Muscle Variation
Palmaris longus
A thin tendon that stands out in the wrist when you press your thumb and little finger together. About 1 in 7 people do not have it at all, and they lose nothing.
Missing in about 15% of people
Muscle Variation
Plantaris muscle
A small calf muscle with a very long, thin tendon that medical students mistake for a nerve. Between 7% and 20% of people do not have it.
Missing in 7–20% of people