Humans began altering natural world 6,000 years ago

Scientists have found an abrupt change about 6,000 years ago in how terrestrial plant and animal species coexisted, right about the time human populations were ballooning and agriculture was spreading around the world.

The findings suggest that human activity had reached a tipping point where hunting and farming were impacting the natural world in irreversible ways — changes that have continued to increase to this day. The researchers, including UC Berkeley’s Cindy Looy, an assistant professor of integrative biology, will report their findings in the Dec. 17 issue of the journal Nature.