Previous researchers mentioned that mass extinctions occurred on Earth due to the comet hit the earth. The collision triggers a very drastic drop in temperature of about 13 thousand years ago. Abrupt climate change known as the Younger-Dryas temperature reversal was seen as a cause of extinction of most mammals, and human ancestors.
However, scientists at Washington University, Missouri, and Royal Hollway, University of London, found that the crystalline carbon is not the whole lump of facts from the element carbon, known as graphene which is usually in the form of sediment.
Professor Andrew Scott, one of the writers in the department of earth sciences Royal Holloway University, said, "Our results dubious one last piece of the widely discussed hypothesis regarding the impact-Younger Dryas."
Scientists deny the controversial theory that after finding a key piece of evidence used to support the idea of a comet impact probably created by a more mundane process.
This theory is based on fresh water from a giant glacial lakes glaciers in the North Atlantic where ocean currents have helped keep most of the ice planet. It becomes the most likely explanation about climate change that triggered the extinction.
Humans also spread to North America. However, after the climate change which suddenly triggered the last ice age, many of these species are already extinct and the number of people estimated to decrease to only a few thousand people.
Three years ago, scientists at the University of Oregon found evidence of exotic materials, including nano-diamonds in the 12 900-year-old sediments are considered as the impact of the comet that crashed into the earth.
However, Scott and Tyrone Daulton professor from Washington University, said that diamonds are misunderstood because they did not find evidence about the collision of comet.
Dr. Douglas Kennett who led a team from the University of Oregon says that scientists previously have been looking in the wrong place.
"Claims based on diamonds before the wrong address, incorrect and misdirected," says Kennett
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