In America sensationally found ancient traces of human
During an excavation in San Diego, CA, American archaeologists found mastodon bones with signs of damage, which, apparently, caused the ancient people.
The Dating of the bones showed that the mastodon lived about 130 thousand years ago, there are almost 100 thousands of years before the most common time of the settlement of America and much earlier exit of modern humans from Africa. A study published in Nature, briefly about it, and unfolded in the scientific community the controversy, reported in his editorial.
Currently, there are two main theories of the colonization of America. According to the theory of the land bridge, early humans first migrated to North America 13-18,5 thousand years ago during the last ice age. According to another version, the initial colonization of the continent took place much earlier, 21-40 thousand years ago, and subsequently, there were several waves of migration. Supporters of both theories agree that the paleo-Indians came to North America from Asia via the Bering land bridge — a land bridge that occurred on the Bering Strait several times.
New discoveries of American archaeologists can push back the date of the first settlement of the continent 100 million years ago. Moreover, in this case, the first settlers are not modern people, Homo Sapiens, who migrated out of Africa approximately 50-90 thousand years ago, and other kinds of people, now extinct. For example, the Neanderthals, who lived 100 thousand years ago on the territory from Western Europe to southern Siberia, or the denisovans who apparently settled in Asia.
The bones of the mastodon (another name — the American mammoth) and stones, which began to argue the scientists, was found in 1992 during repairs to the road on the outskirts of San Diego. In five months of excavations the archaeologists found the tusks, molar teeth, limb bones, several vertebrae and ribs. Some bones were cracked or broken, some were visible the marks of the blows. Next to them, the researchers found five large stones, which served, in their opinion, the “hammer” and “anvil” on which the split bones. On the rocks, scientists found stab marks, scratches and chips. In addition, they found the broken bone fragments and stones.
Scientists conducted an experiment, during which tried to split the stone tools “fresh” bones of elephants and cows. It turned out that the bones appeared similar marks, and the stones, scratches and chips, similar to those which were discovered in San Diego.
The authors made several assumptions. First, the bones of a mammoth could break the ancient people, could be in order to get to your brain or to make them tools. Second, they were able to crack the predators. In addition, the remains of a mammoth could crush sedimentary rocks, and stones they can bring the flow of water.
According to the authors of the work, especially the damaged bones suggests that they were defeated exactly by ancient people. Alternative version of their appearance to look, in their view, unconvincing. First, none of Pleistocene predators could not bite through the femur of a recently killed mammoth or make it a jagged cut. Besides, was found near the fragments of bone indicate that they smashed the stone, which served as a hammer. As for the suggestion that the mammoth squashed sedimentary rocks, according to scientists, it is also not good. Much more fragile vertebrae and ribs of a mastodon was still intact, and massive femur bone was crushed. It says more about the fact that the bones were selectively “processed” people. And finally, and the stones, and the animal was found in a layer of sand, other stones nearby, archaeologists found. So, apparently, the stones brought with them people, and stop the water flow.
After completion of the excavations, the scientists for several years trying to date the mammoth remains. Dating by the radiocarbon method gave nothing, as the bones are not preserved a sufficient amount of collagen required for the study. To determine the age of deposits in which remains were found, using optical Dating was also impossible. This method determines the age of rocks no older than 100 thousand years, in this case sediments were more ancient. In the end, to determine the age of the mammoth was able to use the uranium-thorium method, which allows to date the remains under the age of 500 thousand years. In this case, it turned out that the mammoth lived of 130.7± 9.4 thousand years ago.
“I am sure that many of my colleagues would react to [the discovery] was very skeptical. I’m expecting it. It’s much, much earlier than the time when, according to most archaeologists, hominini settled in North America,” says lead author, Dr. Steven Choline (Steven Holen) from natural history Museum of San Diego.
Indeed, in the scientific community after publication turned stormy debate. The part of archaeologists tend to agree with the evidence given by the authors of the study. So, Alastair pike (Alistair Pike) from the University of Southampton, specializing in the uranium Dating method, said he does not see the obvious flaws in the analysis and the date should be accurate. Archaeologist Erella Hovers (Erella Hovers) from the Hebrew University in Jerusalem, which reviewed an article submitted to Nature, argues that given the authors the evidence persuaded her. “It’s overwhelming,” she said. “[The result] leaves a ton of questions because we only know that in this place and at this time there were some people, and nothing more.”
However, other researchers are more skeptical. Thus, the evolutionary geneticist Pontus Skoglund (Pontus Skoglund) from Harvard medical school believes that the age of the remains could be identified, collect and analyze the DNA of a mammoth. Archaeologist David Meltzer (David Meltzer) from southern Methodist University in Dallas believes that the archaeological evidence is insufficient to make so serious statements. His colleague John Mcnabb (McNabb, John) from the University of Southampton seems strange that in San Diego there was no other traces of the ancient people. Besides, he believes that broken bones need to be studied in more detail.
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