The extinction of the woolly rhinoceros (Coelodonta antiquitatis) at the onset of the Holocene remains an enigma, with conflicting evidence regarding its cause and dynamics. Using a computationally intensive modeling approach and extensive paleontological and ancient DNA information, a team of paleontologists led by University of Adelaide and University of Copenhagen scientists reveals how and why this enigmatic species went extinct.
Woolly rhinoceroses (Coelodonta antiquitatis) were once widely distributed across northern and central Eurasia, before going extinct some 10,000 years ago. Image credit: Mauricio Anton.
The woolly rhinoceros was an iconic member of the mammoth steppe fauna of central and northern Eurasia, originating on the Tibetan plateau approximately 2.5 million years ago.
It was a cold-adapted species covered in thick skin and long fur, with a body size similar to the living African white rhinoceros (Ceratotherium simum).
Based on fossil chronology, the woolly rhinoceros was presumed extinct by 13,900 years ago, despite surviving repeated glacial-interglacial cycles of the Pleistocene.
However, the recent discovery of woolly rhinoceros DNA in early Holocene sediments indicates a later extinction date of 9,800 years ago. While there is ongoing debate surrounding this young age estimate, redeposition of DNA is unlikely to be its cause.
“Using computer models, fossils and ancient DNA, we traced 52,000 years of population history of the woolly rhinoceros across Eurasia at a resolution not previously considered possible,” said University of Adelaide’s Dr. Damien Fordham.
“This showed that from 30,000 years ago, a combination of cooling temperatures and low but sustained hunting by humans caused the woolly rhinoceros to contract its distribution southward, trapping it in a scattering of isolated and rapidly deteriorating habitats at the end of the Last Ice Age.”
“As Earth thawed and temperatures rose, populations of woolly rhinoceros were unable to colonize important new habitats opening up in the north of Eurasia, causing them to destabilise and crash, bringing about their extinction.”
The new study contradicts previous research that found humans had no role in the extinction of the woolly rhinoceros — despite the animal co-occurring with humans for tens of thousands of years prior to its extinction.
“The demographic responses revealed by our analysis were at a much higher resolution to those captured in previous genetic studies,” said University of Copenhagen’s Professor Eline Lorenzen.
“This allowed us to pinpoint important interactions that woolly rhinoceroses had with humans and document how these changed through space and time.”
“One of these largely overlooked interactions was persistent low levels of hunting by humans, probably for food.”
“Humans pose a similar environmental threat today,” the researchers said.
“Populations of large animals have been pushed into fragmented and suboptimal habitat ranges due to over hunting and human land-use change.”
“There were 61 species of large terrestrial herbivores — weighing more than one ton — alive in the late Pleistocene, and only eight of these exist today. Five of those surviving species are rhinoceroses.”
“Our findings reveal how climate change and human activities can lead to megafauna extinctions,” said University of Copenhagen’s Professor David Nogues-Bravo.
“This understanding is crucial for developing conservation strategies to protect currently threatened species, like vulnerable rhinos in Africa and Asia.”
“By studying past extinctions, we can provide valuable lessons for safeguarding Earth’s remaining large animals.”
The study appears in the Proceedings of the National Academy of Sciences.
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Damien A. Fordham et al. 2024. 52,000 years of woolly rhinoceros population dynamics reveal extinction mechanisms. PNAS 121 (24): e2316419121; doi: 10.1073/pnas.2316419121
Source : Breaking Science News