MISE & Agrave; DAY
Mammoths have lived much longer than researchers previously thought, especially in Canada.
DNA analysis from permafrost sediments mined in the region of the Klondike, in central Yukon, has enabled researchers at McMaster University, the University of Alberta, the American Museum of Natural History and the Government of Yukon to shed light on almost 30,000 years of history. story.
According to their findings published in an article in the journal “Nature Communications”, the woolly mammoth and the North American horse, descended from present-day horses, would have persisted until 5,000 years ago. They would thus have lived until the middle of the Holocene, the geological era which began with the end of the last glaciation 11,700 years ago and which still persists today.
Already in strong decline before climatic instability, mammoths and horses would not have immediately become extinct due to excessive human hunting as previously suggested by researchers' estimates.
Using DNA capture-enrichment technology, scientists have reconstructed ancient ecosystems using soil samples containing billions of microscopic genomic sequences of animal and plant species.
They thus painted a portrait of the flora and fauna at different times of the Pleistocene-Holocene transition, an unstable climatic period dating from 11,000 to 14,000 years ago, during which a number of large species such as mammoths, mastodons and saber-toothed cats declined or disappeared.
At that time, the environment in the Yukon underwent major changes. The once rich prairies would have ceased to be so, in part because there were no longer 'ecological engineers' to manage them, the researchers reported.
“Now that we are have these technologies, we realize how much life cycle information is stored in permafrost, ”said Tyler Murchie, postdoctoral researcher in McMaster's Department of Anthropology and lead author of the study.
< p> “The amount of genetic data in permafrost is quite huge and really allows for a scale of ecosystem reconstruction and evolution which is unmatched with other methods to date,” added the researcher.
Scientists also noted in their article the need to collect and archive more permafrost samples, which risk being lost forever as the Arctic warms.