Why was the woolly mammoth driven to extinction? This is up for debate in the scientific community, but new evidence suggests that climate change, not human hunting, may have been the reason these animals disappeared from the planet, BBC News reports.
While some scientists are hard at work trying to clone the ancient beast, others are busy working to understand what made these giant animals, the closest relatives of the Asian elephant, go extinct around 30,000 years ago. A DNA analysis published in the Proceedings of the Royal Society B may provide some clues.
"The picture that seems to be emerging is that they were a fairly dynamic species that went through local extinctions, expansions and migrations. It is quite exciting that so much was going on," Dr. Love Dalen of the Swedish Museum of Natural History, who led the research, told BBC News.
In London, Dalen worked with researchers in analyzing DNA samples from about 300 woolly mammoth remains that they and others from previous studies had collected, tracing migrations patterns, what point in time the mammoths existed, and noting the genetic diversity of their samples. The less diverse the samples were, the lower the population was at the time they existed, the researchers discovered.
The scientists also discovered that the woolly mammoth had nearly gone extinct 120,000 yearas ago when the world temporarily began to warm, mammoth populations speculated to have dropped off from several millions to tens of thousands during this time in history. As the planet entered the Ice Age, the numbers recovered, but nonetheless, the initial decline led to their eventual extinction, around 20,000 years ago "when the Ice Age was at its height, rather than 14,000 years ago when the world began to warm again as previously thought," according to BBC News.
The decline of the mammoths was, they hypothesize, in part spurred by the decline of grasslands that fed them, replaced by forests and tundra. While a debate exists within the scientific community over whether mammoths died out due to climate change or humans hunting them to extinction, the new evidence leads researchers to believe that a drop in temperatures was the ultimate nail in the coffin for the species' demise.
"During the last ice age, between about 50,000 and 20,000 years ago, there were substantial movements of mammoth populations - European populations being replaced by waves of migration from the east, for example," Adrian Lister of the NHM told BBC News. "But from about 20,000 years ago onwards, the population started the dramatic decline that led to its extinction, first on the mainland about 10,000 years ago, and finally on some outlying Arctic islands. The pattern seems to fit forcing by natural climate change: any role of humans in the process has yet to be demonstrated".
