As these scavengers became used to the company of humans, men would adopt them as pets and only breed the tamest and most pliable of the bunch for the eventual goal of using them as haulers, hunters and herders. But how would breeding wolves with other wolves, however tame, produce anything but more wolves?
The answer can be found in a study begun in 1940 by Russian scientists Dmitri Belyaev. He bred silver foxes in Siberia on the sole criteria of friendliness to people. By the 10th generation, the foxes began to show radical physical changes: Ears pointed down, tails pointed up, they started to bark, and they began to have different coats. By breeding for tameness or submission, Belyaev had reduced the adrenalin level in the foxes, which is a biochemical pathway that also controls melanin, which determines the animal's coat color. In fact, breeding for behavior altered the levels of a whole range of hormones, thus triggering a great degree of genetic variation.
Thus, we can deduce that about 10,000 years ago, man began a similar breeding program with wolves, which eventually produced the wide variety of dogs we see today.
Submission in humans
What would happen if you bred humans for tameness or submission? It may have already happened. Among early humans, the most successful at reproducing would have been those tribe members who displayed the most cooperation and submitted to a leader who was the most skilled at hunting and resolving conflicts among tribal members.
As submissive behavior was reinforced and rewarded over generations, humans, like foxes, would have experienced physical changes, such as more delicate facial features, which then became desirable breeding traits. They might not have fully understood the selection process, but probably would have noticed that people in more aggressive tribes, which didn't reward submissive behavior, looked brutish and ugly. Beauty is more than skin deep.
A code for encouraging submission (various thou shalt nots) would become part of the foundation for religion. Evolution causes religion, and religion causes evolution. If rewarding submission helped change human behavior and appearance in the past, shouldn’t we continue such a program in the present and future?