> something is deeply different in dog genes, or in how and when those genes become active, and scientists are trying to determine exactly what it is Darwin famously observed in the first chapter of On the Origin of Species that not one of our domestic animals can be named which has not in some country drooping ears . Darwin himself attributed it to "muscle misuse", the rationale being that domestic animals are not f…
This episode of radiolab goes into some theories about the process of fox domestication and hypothesizes that something similar might have occurred in humans.
I don't remember it in enough detail to summarize, but it's a fascinating listen.