Darwin's tubercle is a congenital ear condition which often presents as a thickening on the helix at the junction of the upper and middle thirds. The feature is present in approximately 10.4% of the population. This acuminate nodule represents the point of the mammalian ear.
This atavistic feature is so called because its description was first published by Charles Darwin in the opening pages of The Descent of Man, as evidence of a vestigial feature indicating common ancestry among primates. However, Darwin himself named it the Woolnerian tip, after Thomas Woolner, a British sculptor who had depicted it in one of his sculptures and had first theorised that it was an atavistic feature.
The gene for Darwin's tubercle is inherited in an autosomal dominant pattern, and has incomplete penetrance, meaning that those who possess the gene will not necessarily present with the phenotype.
Famous quotes containing the word darwin:
“Natural selection, the blind, unconscious, automatic process which Darwin discovered, and which we now know is the explanation for the existence and apparently purposeful form of all life, has no purpose in mind. It has no mind and no mind’s eye. It does not plan for the future. It has no vision, no foresight, no sight at all. If it can be said to play the role of the watchmaker in nature, it is the blind watchmaker.”
—Richard Dawkins (b. 1941)