“It must have been something that thousands of other geneticists looked at”
Apes lost their tails about 25 million years ago, and the trigger is an AluY insertion in the TBXT gene that biologists had written off as junk DNA. Bo Xia spotted it browsing a public genome database. Mice engineered to lose their tails also developed neural tube defects like spina bifida. Humans got upright posture later and kept the bill.