Ten thousand years ago, at the dawn of the agricultural revolution, many of our worst infectious diseases didn’t exist.
Here’s what changed.
With the rise of agriculture, for the first time in history humans were living in close contact with domesticated animals — milking them, taking care of them and, of course, eating them. All that touching and sharing gave animal germs plenty of chances to get inside us.
Take measles. Researchers think that up until about 5,000 years ago, it didn’t exist. But its older cousin rinderpest, a cattle disease, did. When humans began spending so much quality time with cows, little rinderpest germs started jumping over into us. And a few of the germs had a mutation that allowed rinderpest to evolve from a cattle disease into measles, a deadly human virus.