Did comets cause extinction in ancient America?

The debate is heating up around a controversial hypothesis that the very strong collision with comets caused the huge North American mammals to become extinct nearly 13,000 years ago.

The first hypothesis given in May 2007 suggested that the onslaught of extraterrestrial objects that caused mass extinctions was known under the name Younger Dryas and caused a period of low temperature. low. This hypothesis has been widely debated since it was launched, but it attracted more interest at the annual American Archaeological Community meeting in Vancouver, Canada in March.

Stuart Fiedel of the Louis Berger Group, a private archaeological company in Richmond, Virginia, argues that the hypothesis cannot answer important questions - such as how the comet collision killed ghosts. -muck and cat-toothed cats in North America while humans are not affected .

'If this effect is strong enough to wipe out mammoths, mastodons, short-faced bears and other large flora and fauna present on this land, you will think that it also massacred all humans - not just through direct heat shock but also rob their food source. '

'So there must be a significant decrease or eradication of humanity and we do not see it. Basically, judgment must be based on whether this is possible when comparing on data and vice versa. Now I don't think it explains some obvious things. '

An illustration of a mammoth and mastodon.The debate is heating up around a hypothesis that the very strong collision with comets has wiped out mammals in North America nearly 13,000 years ago.(Photo: Raul Martin / NGS)

The mysterious phenomenon of global cooling

No matter how it happened, experts agreed that the earth suffered a pretty strong impact about 12,900 years ago. The world is in the middle of the last ice age, when the Younger Dryas event is difficult to bring the earth back to a temperature near the ice. This anomalous period lasts about 13,000 years.

A widely accepted theory is that icebergs melt and ice lakes 12,000 years ago poured so much water from the ice into the oceans that it interfered with the ocean cycle . This chills most of the earth, especially in the Northern Hemisphere.

Also during this period, large body mammals including mammoths, mastodons, horses, swords and cat teeth were extinct in North America. Previous theories suggest that primitive humans have died of large animals when overfishing and prolonged hunting.

James Kennett, a geologist at the University of California, Santa Barbara, is one of the proponents of the comet collision theory. He argued that this hypothesis was consistent with explaining and linking different events.'We think it is a series of aerial explosions, like the Tunguska incident in a row . like a shotgun.' He mentions the explosion of extraterrestrial objects in Siberia in 1908. That also explains the grass patches in the North American region. Kennett and colleagues discovered countless diamond and magnetic molecules present everywhere in the soil dating back to this time.

'These properties are formed in extremely hot and high pressure environments caused by a series of explosions. Obviously this is an unacceptable hypothesis, in the sense that it is not anticipated. But all I can say is that I am not aware of any process that could be responsible for much of the data that we have and continue to have rather than an extraterrestrial collision. '

South American puzzle

In Fiedel's review of the hypothesis, he also gave archaeological evidence that he deemed inconsistent with the comet theory.'Clear lack of synchronization with what happens in South America'

Radiocarbon dating and other data show that the giant flora and fauna in South America survived centuries after the northern brother was wiped out. 'You have to wonder what kind of collision gets weaker before it reaches Mexico and doesn't affect much on South America.'

Kennett agrees this is considered inconsistent. 'South America is an important hypothetical test point.' However, he argued that the time of extinction in the north and the south was based on radiocarbon technology, which could be considered unified, provided there was a tight error. He added that more data should be collected from these areas to better understand the exact time of extinction in South Africa.

The challenge of dating

Gary Haynes is an anthropologist at Nevada University, Reno. He said he was not sure radioactive carbon data could help answer these questions.The increase in CO2 in the atmosphere during the Younger Dryas event is believed to make the dating of radiocarbon dating from this period inaccurate . 'It is very difficult to make certain decisions. So it is impossible to talk about the cause based on those vague evidence. '

On his side, Kennett said this hypothesis is still in the early stages. Currently, only one academic paper on the hypothesis has been published. Kennett said more is in the building based on additional data and analysis that he and his colleagues have done over the past year.

' This is the first group to ever test the possibility of alien collisions at the time of systemic flora and fauna extinction. So basically we are in the process of testing hypotheses. This will take time. '