While many of the hangovers from our “devolved” past are visible or physical, this is not true for all. Humans have structures in their genetic make-up that were once used to produces enzymes to process vitamin C (it is called L-gulonolactone oxidase).
Most other animals have this functioning DNA but at some point in our history, a mutation disbled the gene – whilst leaving behind its remnants as junk DNA.
This particular junk DNA indicates a common ancestry with other species on earth, so it is particularly interesting.
