Evolution: Darwin’s Tubercle

Known as Darwin’s tubercle, about 10.4% of the population have a small bump on the inside of their upper ear.  In 1879, Charles Darwin mentioned this bump in The Descent of Man as evidence of a vestigial feature indicating common ancestry among primates. Darwin actually 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 evolutionary.

Darwin’s tubercle has been used to demonstrate basic genetics; that the feature is controlled by a single gene with two alleles, and the allele for Darwin’s tubercle is dominant. This theory has been disputed citing that family and twin studies indicate that there may be very little genetic influence on the trait.

(University of Delaware, Wiki)