Ape ancestors lost their tails with a single mutation?

[structureoftruth (Matthew Dickau)]

@Chris_Falter, @evograd beat you to the punch.

How we lost our tails (new preprint)

Most primates have tails, but us humans and the other apes (chimps, gorillas, orangutans, and gibbons) are all tail-less. Clearly, having tails was the ancestral primate condition, so how did apes (AKA hominoids) end up losing their tails? [Screenshot 2021-09-17 at 00.54.36] Earlier today a new preprint was released at least partially answering this question: The paper is well written and IMO very accessible to non-specialists, so I’d recommend checking it out. I’ll summarise it briefly though… To look for the genetic basis of the loss of tails, the authors started with a list of 31 genes known to be involved in tail development from mouse studies. First, they looked for any protein-coding mutations that might disrupt the ape homologs of these 31 genes, but didn’t find any promising candidates. So they looked at the non-coding sequences. They found an ape-specific insertion of a ~300bp Alu element in the 6th intron of a gene called TBXT. The image below shows UCSC genome browser …