How did dogs become domesticated?
From wolves, tens of thousands of years ago — and the evidence increasingly suggests that dogs largely domesticated themselves rather than being captured and tamed by people.
The self-domestication hypothesis. Wolves that were less fearful of humans could exploit a new food source: the waste around human settlements. Those bolder animals fed better, survived better, and bred. Over generations, selection for reduced fear produced a population that tolerated and then sought human proximity. Nobody had to plan it.
The evidence for this includes the fact that tameness is heritable and selectable, demonstrated dramatically by a long-running Russian experiment with silver foxes. Selecting only for reduced fear of humans produced, within decades, animals that were not merely tamer but had floppy ears, curled tails, patchy coats, shorter snouts and altered breeding cycles — a suite of traits that appear together across many domesticated species, known as domestication syndrome. Dogs show them too.
What is still debated, and genuinely so: when it happened, with estimates ranging from roughly 15,000 to over 30,000 years ago; where, with evidence pointing variously to Europe, Siberia and East Asia, and possibly more than one event; and whether there were multiple domestications with later interbreeding. Ancient DNA has repeatedly overturned earlier conclusions.
What is clear. Dogs diverged from a wolf population that is now extinct — modern wolves are their cousins, not their ancestors. Domestication preceded agriculture, meaning dogs were companions of hunter-gatherers.
What changed in the dog. Beyond appearance: the ability to digest starch, which arose later alongside agriculture; the capacity to follow human pointing and eye gaze, which wolves raised identically do far less well; a tendency to look to humans when facing an unsolvable problem, where wolves persist alone; and the retention of juvenile behaviours into adulthood.
Breeds are recent. Most modern breeds were created in the last two hundred years through intensive selection for appearance — a tiny fraction of the domestication story, and the source of many health problems.