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.
Showing 7 oddities.
This tag marks entries that are leftovers from evolutionary ancestors, structures or reflexes that once had a clear use and now do little or nothing. Goosebumps, the plantaris muscle, and Darwin's tubercle are all remnants of a body plan built for a different environment.
The tag exists for the reader curious about why the body still bothers with something that seems pointless now. That curiosity is well placed. Evolution removes structures slowly, and only when keeping them costs something.
This list will tell you what the structure or reflex used to do, in an ancestor species, and why it survives today. It will not claim the feature is harmful. A vestigial trait can sit there, unused, without costing you anything at all.
Spiritual 5Icky 5Not an emergency 21Get it checked 15Try it 67Learnable 18Party trick 19Vestigial 7Genetic 37Sleep 6Illusion 22Childhood 8Debunked myth 11Community 14Famous people 14Record 7
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Ears Trick
Ear wiggling
Moving the outer ears using three small muscles that most mammals use to point their ears at sounds. About 1 in 5 people can wiggle their ears. Some people can learn.
About 1 in 5
Skin Reflex
Goosebumps
Tiny muscles at the base of most hairs 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 the raised hair 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
Muscle Variation
Linburg–Comstock variation
An extra tendon link in the forearm that ties the thumb to the index finger. When the thumb bends into the palm, the index fingertip bends with it. Roughly 1 in 5 people have it, but counts vary widely.
About 1 in 5 people. Studies range from 5% to 60%.
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 15–20% 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