Early human arrivals in North America?
A group of scientists has claimed that ancient humans may have settled in North America as long as 130,000 years ago—some 115,000 years earlier than previously thought. The controversial assertion, which is viewed with skepticism by most other paleontologists, is based on analysis of the fossilized remains of a mastodon, a long-extinct mammoth-like animal. Discovered beside a freeway near San Diego in 1992, the mastodon bones were scratched and broken into many pieces, surrounded by several large rocks that may have served as hammers and anvils. Researchers at the University of Michigan and elsewhere have concluded that the bones are 130,000 years old, and that they were opened when fresh by a Neanderthal or other ancient human relative using rocks to try to extract bone marrow. It’s widely accepted that Homo sapiens arrived in North America about 15,000 years ago, across a land bridge connecting Siberia and Alaska; the mastodon findings, if confirmed, would indicate that another hominin species somehow reached this continent much earlier. If that hypothesis is true, it would rewrite the story of human migration. Skeptics argue that there are more-plausible explanations for the bone fractures and markings, such as pressure from the sediment on top of it. Paleontologist Thomas A. Deméré, a coauthor of the study, acknowledged that the findings seem “impossible,’’ but said, “People have to be open to the possibility that humans were here this long ago.’’
Tom Deméré/San Diego Natural History Museum, Getty (2) ■