"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."

John Poole reports for NPR February 9, 2017. [2]