On the News | USA | Controversial study claims humans reached Americas 100,000 years earlier than thought @ Nature News and Comments

On the News @ Nature News & Comments


Controversial study claims humans reached Americas 100,000 years earlier than thought


A ‘hammer’ stone — possibly shaped by ancient humans — found in California and dated to 130,000 years ago.
Image Credit: A. Rountrey, C. Abraczinskas and D. Fisher/Univ. Michigan

“Ancient humans settled in North America around 130,000 years ago, suggests a controversial study — pushing the date back more than 100,000 years earlier than most scientists accept. The jaw-dropping claim, made in Nature, is based on broken rocks and mastodon bones found in California that a team of researchers say point to human activity.

Their contention, if correct, would force a dramatic rethink of when and how the Americas were first settled — and who by. Most scientists subscribe to the view that Homo sapiens arrived in North America less than 20,000 years ago. The latest study raises the possibility that another hominin species, such as Neanderthals or a group known as Denisovans, somehow made it from Asia to North America before that and flourished.

“It’s such an amazing find and — if it’s genuine — it’s a game-changer. It really does shift the ground completely,” says John McNabb, a Palaeolithic archaeologist at the University of Southampton, UK. “I suspect there will be a lot of reaction to the paper, and most of it is not going to be acceptance.”

The study focuses on ancient animal-bone fragments found in 1992 during road repairs in suburban San Diego. The find halted construction, and palaeontologist Tom Deméré of the San Diego Natural History Museum led a five-month excavation. His crew uncovered teeth, tusks and bones of an extinct relative of elephants called a mastodon (Mammut americanum), alongside large broken and worn rocks. The material was buried in fine silt left by flowing water, but Deméré felt the rocks were too large to have been carried by the stream.

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“We thought of some possible explanations for this pattern, and the process we kept coming back to was that humans might be involved,” he says. Attempts in the 1990s to date the site suggested that the ivory was some 300,000 years old, but Deméré was sceptical: the method his colleagues used was problematic, and the age seemed so improbable for humans to be living in California.” (…) READ MORE

Lurdes Fonseca

Assistant Professor and Researcher at University of Lisbon
Sociologist (PhD), Paleontologist (Researcher in Micropaleontology), Majors in Sociology and Biology, Minor in Geology. Main interests in Paleontology: Microfossils, Molecular fossils, Paleobiology and Paleoecology. (read more about me)