One of the chief characteristics of domesticated animals is their reduced aggression compared to wild types. Tame dogs, cats, cattle and goats, are much more tolerant of others and more social than their feral versions. This acquired tameness is why we can work close with them. In addition, domestication brings morphological changes to the skulls of adults – they resemble the young more with larger wider eyes, smaller teeth, flatter rounder faces, and more slender bones. Tame dogs look like wolf puppies, and domesticated cats more like lion kittens.

Although wolves were domesticated into dogs in several regions of the world around 15 to 40 thousand years ago, they were not the first animals to be domesticated. We were. Homo sapiens may have been the first species to select for these genes. When anthropologists compare the morphological features of modern humans to our immediate ancestors like the Neanderthal and Denisovans, humans display neoteny. Humans resemble juvenile Neanderthal, with rounder falter faces, shorter jaws with smaller teeth, and slender bones. And in fact the differences between a modern human skull and a Neanderthal skull parallel those between a dog and its wild wolf ancestor.

We invented our humanity. We invented cooking, we invented human language, we invented our sense of fairness, duty, and responsibility. All these came intentionally, out our imaginations of what could be. To the fullest extent possible, all the traits that we call “human” in contrast to either “animal” or “nature,” are traits that we created for ourselves. We self-selected our character, and crafted this being called human. In a real sense we collectively chose to be human.