According to a recent study, humans caused the extinction of woolly mammoths, although it had previously been alleged that climate change was the main factor.
The discovery was made by paleontologists at the University of Michigan, after assessing isotopic signatures in 15 tusks belonging to juvenile Siberian woolly mammoths, aged between 3 and 12. The smallest tusk was around 10 inches long, while the largest was approximately 30 inches long.
The fossils, which were between 10,000 and 40,000 years old, had been collected over the last 20 years by Museum of Paleontology Director Daniel Fisher, who contributed to the research.
Experts performed CT scans and analyzed the ratio between two nitrogen isotopes (nitrogen-14 and nitrogen-15), in order to determine the weaning age of woolly mammoths. Previously, a study conducted on elephant calves had proved that this proportion decreased as the animals stopped nursing and replaced milk with solid foods.
Researchers discovered that the weaning age of the prehistoric mammals was lowered from 8 to 5 in a period of 30,000 years which culminated with the woolly mammoth’s extinction.
This suggests that in fact human hunters were the ones that contributed to the species’ demise and proves this idea by using significant data, from a wide range of geologic ages.
While in the past it had been believed that climate change was to blame for this phenomenon, in fact the nutritional stress that results from oscillating temperatures actually causes weaning to be postponed.
This has been shown by studies analyzing modern elephants, and most likely the same reaction would’ve been encountered among woolly mammoths as well.
On the other hand, when animals are hunted excessively, this increases the speed of their maturation process, which eventually results in premature weaning.
Therefore, as researchers explain, this new study provides the scientific world with compelling evidence regarding the true cause of woolly mammoth extinction.
In fact, an increasing number of studies in recent years have been suggesting that warming weather didn’t seem like a plausible explanation for the disappearance of so many Ice Age mammals.
“These findings will not end, the debate, but we hope they will show people the promise of a new approach toward solving a question that, so far, has just led to divided camps”, declared Michael Cherney, study co-author and doctoral student in the University of Michigan’s Department of Earth and Environmental Sciences.
The elephant-like woolly mammoths perished from North America and Siberia approximately 10,000 years ago, at the end of the the last glacial period, popularly known as the Ice Age.
At that time, many other prehistoric mammals disappeared as well, and paleontologists have long been speculating which was the driving force behind this mass extinction.
Therefore, it seems indeed that this recent study sheds new light on this matter, and the mystery might soon be resolved. For now, these important findings have been presented at the 75th anniversary meeting of the Society of Vertebrate Paleontology, which was held in Dallas, Texas, between October 14 and 17.
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