A new study published in the journal Nature suggests that humans may have reached North America 100,000 years earlier than previously thought.
The study looks at mastodon bone fragments and worn rocks found at a site in suburban San Diego, California, during road construction in 1992. Scientists looking at the fragments believe they may indicate tool use. If true, it would mean that another human species – possibly homo erectus, Neanderthals, or Denisovans – reached the area long before homo sapiens.
Most scientists put the earliest human activities in North America at about 20,000 years ago, although some have cited evidence that indicates human presence 40,000 years ago.
Some scientists are skeptical that the San Diego discovery puts humans on the West Coast 130,000 years ago, but most, including the archaeologist who authored the Nature study, say more research is in order.
