When I was a kid I was totally fascinated by this little bump on my right ear. If I feel the outside of my ear, along the edge, I can still feel that little bump. Maybe you have a little cartilage there too. Do you?
It's called Darwin's point and is a relic of our mammalian past.
The heritable trait runs dominant, which means if either of your parents gave you a gene for the point, you'll express the trait and have a little bump on your ear too.
According to the article "On the Pithecoid Type of Ear in Man" published in 1899 by the Zoological Bulletin, half of men and one-third of women have one. Several decades before, when the pseudoscience of phrenology was all the rage, people thought the trait was associated with criminality. It's tied to criminal propensity as much as it is to the appendix, which is to say — not at all.