The animals of the Ice Age, including the woolly mammoth and woolly rhinoceros, have been the subject of a recent study. Researchers have discovered that humans may not be to blame for their extinction after all. They found new information that leads them to believe a small flowering plant died out due to climate change, thus cutting off the only source of the animals’ protein supply.
The researchers studied 242 samples from permafrost sediment, which was able to preserve the remains of the animals, along with their stomach contents. The mummified remains found in the fossils of the animals were located in 17 locations, including Siberia and North America. They found more than grass in their stomach content though. Apparently they ate wildflowers, known as forbs. Until now, there was not any evidence of flowers on the steppes. The idea of flowering plants covering the land reveals a different type of landscape than what scientists first pictured.
The DNA preserved in Arctic sediments of animal remains shows that they relied on protein-rich flowers, which covered the landscape at the time of their existence. Samples from mammoths, rhinos, horses, reindeer and elk all showed that forbs were a staple in their diet. They found that flowering species were a large part of the animals’ diet. Climate change then damaged the flowers, reducing the amount of protein available to the Arctic animals. Only grass and shrubs remained as a food source, as reported on Wednesday in the journal Nature.
The change in temperatures occurred between 10,00 and 25,000 years ago, lining up with the same time-frame as the animals’ extinction. During that same time, two-thirds of the Arctic giants went extinct, according to researchers. The research also pulls into question the theory of human life being the cause of their extinction. Hunting by humans may not have led to the demise of the mammoths and rhinos that once roamed the Earth, though they may have added to the problems they were already dealing with.
Eske Willerslev, a DNA expert from the University of Copenhagen, led the research team. “We think that the major driver (of the mass destruction) is not the humans,” he said. Though he added that they may have put the final nail in the coffin, as the Ice Age animals were already at risk for extinction due to the climate change.
As the climate changed and the Ice Age came to a close, the wet, warmer weather made it difficult for the wildflowers to survive. The growth rate of the trees and shrubs accelerated and likely overshadowed the flowered plants and caused them to die out.
The higher temperatures, in turn, may be the reason for diminishing the entire ecosystem. Reducing their food source and taking away the protein the animals used to stay strong may have played a bigger role in ending their existence. Based on the results of this study, it appears that the flowers died off due to climate changes, which were responsible for the extinction of the Ice Age animals, not humans.
By Tracy Rose