2017-04-26 19:29:09 UTC
"Researchers in Southern California say they've uncovered evidence that
humans lived there 130,000 years ago.
If it's true, it would be the oldest sign of humans in the Americas ever
predating the best evidence up to now by about 115,000 years. And the
claim has scientists wondering whether to believe it.
In 1992, archaeologists working a highway construction site in San Diego
County found the partial skeleton of a mastodon, an elephant-like animal
now extinct. Mastodon skeletons aren't so unusual, but there was other
strange stuff with it.
"The remains were in association with a number of sharply broken rocks
and broken bones," says Tom Deméré, a paleontologist at the San Diego
Natural History Museum. He says the rocks showed clear marks of having
been used as hammers and an anvil. And some of the mastodon bones as
well as a tooth showed fractures characteristic of being whacked,
apparently with those stones."
'"That is an order of magnitude difference. Wow," says John Shea, an
archaeologist at New York's Stony Brook University who specializes in
studying ancient toolmaking. "If it's correct, then there's an
extraordinarily ancient dispersal to the New World that has a very
different archaeological signature from anything left behind by recent
Shea says it's different because Stone Age toolmakers usually leave
behind stone flakes sharp pieces broken or "knapped" from certain
kinds of rock that serve as cutting implements. There were none at the
California site. Another odd thing: no signs that the mastodon was
butchered for the meat.
"This is weird," Shea says. "It's an outlier in terms of what
archaeological sites from that time range look like everywhere else on
the planet." He suggests these bones might have been broken up by
natural causes by a mudflow, perhaps, or by the trampling of animals
sometime after the mastodon died.
Another skeptic is John McNabb, an archaeologist at the University of
Southampton in England. His question: How did those people get to
"The California team counters that it has spent over 20 years examining
the evidence. "I know people will be skeptical with this because it is
so surprising," says team member and archaeologist Steve Holen, "and I
was skeptical when I first looked at the material myself. But it's
definitely an archaeological site."
Holen, with the Center for American Paleolithic Research, says these
early people could have come across in boats. As for the broken bones,
he says the type of fracture isn't accidental. And the way the
hammerstones and bones were distributed in the ground doesn't look
One question the team can't answer is who these people were. A genetic
technique that uses mutations in a population's genome as a sort of
"clock" says the first common ancestor of Native Americans lived about
20,000 years ago. So if there were indeed earlier settlers, it could be
they made an arduous migration from Siberia, only to die out without
leaving any descendants."