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The hypothesis that humans arrived in America from Asia through the Bering strait 13,000 years ago every time it holds less. Last year the journal Science published the discovery in the northeast of the US a few tools similar to those found in the japanese island of Hokkaido. Dating around 16,000 years old and supported the theory that migration from Japan to America was coastal.
Now, two new studies, published this time in the journal Nature, provide new evidence on how and when began the peopling of the american continent. According to the dating of almost 1,900 of stone tools, as well as vegetable remains and DNA of fossils of animals found in the cave of Chiquihuite in Zacatecas , Mexico, the first inhabitants of America would have reached some 31,000 or 30,000 year s, during the Last Glacial Maximum, the time of maximum extension of the ice sheets.
The analysis of the lithic industry found in the cave, located about 2.740 meters of altitude, reveal, in addition, that belonged to a culture that was unknown until now. “These tools have not yet been found in any other place in North America. No other industry shares similarities with her”, tells SINC Lorena Becerra-Valdivia, scientific, archaeological of the universities of Oxford (Uk) and New South Wales (Australia), co-author of both studies, in Nature and a member of the team responsible for defining the chronology in the work of Science.
According to experts, the technology used for the manufacture of these artifacts known to the archaeological record of the Americas was possibly brought from other places before the last Glacial Maximum. The work also underlines that not only the type of tools is atypical, but also the very cave where they were found.
the elevation of The reservoir forced its occupants to adapt to mountainous landscapes, a behavior, until now, never observed in other populations of the Pleistocene in America. This site breaks with the pattern of the hunting of the megafauna, the open places and the shelter of rocks shallow.
To the researchers, it would need to analyze more DNA, archaeological and environmental to better elucidate the origins of the inhabitants of the cave of Chiquihuite, as well as their relationship biocultural with other groups, older indians Clovis and the path that they followed their ancestors to the Americas.
stone-Tool found below the layer of the last glacial maximum – Ciprian ArdeleanPatrones scattering human in America
Until now, the main hypothesis pointed to a first colonization of the continent, a part of the Clovis culture about 13,000 years ago. However, thanks to the techniques of radiocarbon dating and luminescence, as well as the modeling of age-bayesian, the tools found in a sequence of strata of three meters deep to illustrate a completely different scenario.
“there Were humans in North America prior to, during and immediately after the Last Glacial Maximum, but the populations were expanded significantly across the continent much later,” says Becerra-Valdivia.
“there Were humans in North America prior to, during and immediately after the Last Glacial Maximum, but the populations expanded across the continent much later,” says Becerra-Valdivia
According to the researcher, the dispersion of the people to the north of the continent happened during a period of global warming, abrupt at the end of the Ice Age, between about 14.700 and 12.900 years. “From here there is the simultaneous onset of three major traditions of stone tools: the cultures of Beringia, Clovis, and the so-called Western Stemmed”, clarifies the expert.
The dating suggests that the first cross between humans in America came about when the former Beringia, the region where is situated the Bering strait, was completely or partially submerged under the water, between 57,000 and more than 29,000 years. “This suggests that humans have a certain degree of adaptation to maritime or landlocked,” says the researcher, referring to the sea as a mode of coming to America.
The expansion of humans in America joins the extinction of certain animal species. had Previously been linked with the disappearance of 37 genera, a hypothesis known as ‘sobrematanza’. However, other studies have suggested other factors such as the weather. The results published in Nature show that the human presence on the continent precedes the majority of occurrences of the genera became extinct in North America, including camels, horses and mammoths.
“this new evidence is further proof of the complex and dynamic than was the process of peopling of the american continent. Now, more research is needed on the expansion to South America in order to understand the full pattern of migration,” concludes Becerra-Valdivia.