Darwin's tubercle

How it works

The outer ear is a sheet of cartilage covered in skin. Its folded outer rim is the helix. In some people the helix has a small thickening on its upper back edge, about level with the top of the ear canal¹. It looks like a tiny point or knot. It can be on one ear or both, and it varies from a barely visible ridge to a clear bump.

The tubercle forms in the embryo, at the stage when the ear rim is still folding¹. Its presence runs in families, but it does not follow a simple dominant or recessive pattern. Many genes are involved¹.

Prevalence depends heavily on who is counted and how carefully. One study found it in about 10% of Spanish adults. Another found it in 58% of Swedish schoolchildren¹. Studies use different definitions of what counts as a bump, which explains part of the gap.

Try it

1. Look at your ear in a mirror, or feel it with a finger.
2. Follow the folded rim from the top of the ear down and back.
3. Feel for a small thickening on the inside edge of the rim, roughly a third of the way down.
4. Check the other ear. Many people have it on one side only.

History and culture

Charles Darwin described the bump in The Descent of Man in 1871². He credited the sculptor Thomas Woolner with pointing it out to him¹. Darwin argued that it was the folded-over tip of the pointed ear seen in many monkeys, and so a trace of human ancestry². Modern anatomists still list it as a vestigial feature, though the case is weaker than for other traits, since primate ear tips do not map cleanly onto the tubercle³. Fiction gives pointed ears to elves and Vulcans. Darwin’s tubercle is the closest a normal human ear gets.