. . Russian geneticist named Dmitri Belyaev began with the tamest foxes he could find. From their offspring, and for many generations thereafter, he chose only the tamest for breeding. By the tenth generation, they started to bark --they started to have different coats. What does tameness have to do with ears, and barking and coat color?
. . They checked the foxes' adrenaline levels -—that's the hormone that controls the "fight or flight" response—- and they found they were far lower than normal.
. . But where does the multi-colored coat come from? And somebody says right off the bat, "Hey, adrenaline's on a biochemical pathway that also goes to melanin, also has something to do with the animal's coat color." So there's a correlation between coat color now and the adrenal gland. These hormones, in turn, set off a cascade of changes that somehow triggered a surprising degree of genetic variation.
. . Just the simple act of selecting for tameness destabilized the genetic make up of these animals in such a way that all sorts of stuff that you would never normally see in a wild population suddenly appeared. Dogs are pre-adapted to living in fairly complicated social groups. Low-ranking wolves are adept at sucking up to their more powerful pack mates. Dogs use many of those same skills with people.
. . The idea was: dogs tipped the evolutionary balance in favor of us; and that dogs gave us a reason to invent language.
. . There are two parts to the gene. There's the famous part, which encodes proteins. Then there's the less-appreciated part, where I think the real action is, and this is in the so-called "regulatory" DNA. It tells the protein coding part of the gene where and when to be active. All these dogs could have the same genes for leg growth, the only difference may be in when those genes are turned on and off.
. . A dogs' critical period for social development is probably about the first 16 weeks. In wolves, that signal comes when they're about three weeks old, which means dogs have five times as long to form social bonds.
. . Every predator hunts in basically the same way. It starts with "search", which turns into "eye-stalk" when a potential meal is found. Once close enough, "chase" begins. "Grab-bite" brings dinner down, and "kill-bite" finishes the job.