Paleontologists have been dealing with a long-standing mystery regarding when mammoths actually went extinct. SciTechDaily notes how this is so, especially with how the creature's decline seemingly matched human arrival within North and South America.
Given this timely matching up of events, many have wondered whether human efforts contributed to mammoth extinction more than 10,000 years ago.
Mammoth Extinction Timeline Refuted
According to the European Times, a paleontologist from the University of Cincinnati refuted the 2021 released timeline regarding mammoth extinction, suggesting that mammoths became extinct more recently than thought.
A global research team looked into the environmental DNA of mammoth remains as well as over 1,500 Arctic plants. By doing so, they were able to conclude that wetter climates rapidly altered the landscape, transforming it from a tundra grassland into a forested wetland. Such landscapes were incapable of supporting these huge animals and thus led to mammoth extinction just around 3,900 years ago.
However, a 2022 Nature rebuttal paper argues that the environmental DNA on which the latest timeline was grounded is more complex than thought. This was argued by study author and assistant professor Joshua Miller from the UC College of Arts and co-author Carl Simpson from the University of Colorado Boulder.
Age of Environmental DNA Questioned
Miller notes that the main concern is that the age of the DNA is not known. Miller further states that sedimentary deposits are quite complicated as different-aged materials get buried together routinely.
While specialists have various tools to date the deposits and the materials within them, Miller notes that this is not the case for everything. Not all things end up getting successfully dated.
Radiocarbon dating can be performed on various things, including leaves, teeth, charcoal, and bones. Miller notes how powerful this is. However, specialists are currently unable to independently date DNA spotted within sedimentary deposits.
Considering various recent discoveries, specialists know that various ice-age species that died many thousands of years ago could get mummified due to the dry and cold conditions of the Arctic. Miller notes how researchers are incapable of determining whether the environmental DNA sample that was kept within sediments was from a dead or living animal.
Miller notes how organisms shed DNA at all times. It even gets shed long after the death of a species. In areas where decomposition does not occur rapidly, long-extinct and long-dead species may still leave remnants in their surroundings. In areas like the Arctic and other places with extremely cold weather, it may take over thousands of years for decomposition to take place.
The specialists note that the slow decomposition within the arctic region may be the reason why mammoth DNA appeared much later than the recent fossil discoveries. The study also notes how mummified elephant seals, which are close to Antarctica, could date back to over 5,000 years ago.
Miller states that the mystery regarding the role of humans in mammal extinction is still a play. Humans were recognized for utilizing fire in order to change the landscapes. They also hunted for mammoths and made their tusks of ivory.
When, then, did the mammoth extinction start? Experts think that the majority of the mammoths went extinct over 10,000 years ago. However, remaining populations stayed in areas, like Wrangel Island in Russia, until relatively more recently.
Read also: Mammuthus Primigenius: How Gene Deletion Helped in the Evolution and Survival of the Woolly Mammoth
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