Pleistocene landscape in northern Spain with woolly mammoths (Mammuthus primigenius), equids, a woolly rhinoceros (Coelodonta antiquitatis), and European cave lions (Panthera leo spelaea) with a reindeer carcass.
Image credit: Mauricio Antón.
I spend a couple of days away from science papers writing about my other major interests, history and art, instead and what do I find? Scientists have only gone and produced six more papers which casually refute the childish superstition of creationism, so I will now need to spend a few days catching up.
The first of them deals with the findings that humans might well have been the cause of the extinction of the woolly rhinoceros, Coelodonta antiquitatis, in Eurasia, by causing their population to fragment and then collapse altogether over a period starting about 30,000 years ago and ending about 14,000 years ago . This was between 20,000 and 4,000 years before creationists think Earth was magicked up out of nothing by some magic words, spoken in a language that no-one else spoke, by a magic man who had magically self-assembled out of nothing, according to a design it had made before it existed.
The woolly rhinoceros was a cold-adapted megaherbivore widely distributed across northern Eurasia during the Late Pleistocene epoch.
This species first appeared some 350,000 years ago and became extinct approximately 14,000 years ago. In other words, the entire species lived in that immense span of time before creationism's legendary god decided to create the universe consisting of a small flat planet with a dome over it that it is famous for in ancient legends.
What caused that rapid extinction was the subject of a study by an international team of researchers, led by scientists from the University of Adelaide and University of Copenhagen, using computer modelling to make the discovery, shedding light on an aeons-old mystery.
Their findings are the subject of a paper in Proceedings of the National Academy of Sciences (PNAS), which sadly lies behind a paywall, with on the Abstract freely available. Their work is also described in a University of Adelaide news release:
Researchers have discovered sustained hunting by humans prevented the woolly rhinoceros from accessing favourable habitats as Earth warmed following the Last Ice Age.
An international team of researchers, led by scientists from the University of Adelaide and University of Copenhagen, used computer modelling to make the discovery, shedding light on an aeons-old mystery.
An iconic species of megafauna, the woolly rhinoceros had thick skin and long fur, and it once roamed the mammoth step of northern and central Eurasia, before its extinction around 10,000 years ago. This recent discovery, published in PNAS , 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.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.
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 colonise important new habitats opening up in the north of Eurasia, causing them to destabilise and crash, bringing about their extinction.
Associate Professor Damien A. Fordham, lead author
The Environment Institute
School of Biological Sciences
University of Adelaide, Adelaide SA, Australia.Humans pose a similar environmental threat today. 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 tonne – alive in the late Pleistocene, and only eight of these exist today. Five of those surviving species are rhinoceroses.The demographic responses revealed by our analysis were at a much higher resolution to those captured in previous genetic studies. 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.
Professor Eline D. Lorenzen, Co-author
Globe Institute
University of Copenhagen, Copenhagen, Denmark.Our findings reveal how climate change and human activities can lead to megafauna extinctions. 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.
Professor David Nogues-Bravo, co-author
Center for Macroecology, Evolution, and Climate
Globe Institute
University of Copenhagen, Copenhagen, Denmark.
Significance
Using a computationally intensive modeling approach and extensive paleontological and ancient DNA information, we reveal how and why the woolly rhinoceros went extinct at a fine spatiotemporal resolution. Our population reconstructions indicate that a combination of climate-driven habitat fragmentation and low but persistent levels of hunting by humans weakened metapopulation processes and caused their extinction. Our results provide a deeper understanding of the structure and dynamics of past extinctions of megafauna, simultaneously providing valuable lessons to safeguard Earth’s remaining large animals.
Abstract
The extinction of the woolly rhinoceros (Coelodonta antiquitatis) at the onset of the Holocene remains an enigma, with conflicting evidence regarding its cause and spatiotemporal dynamics. This partly reflects challenges in determining demographic responses of late Quaternary megafauna to climatic and anthropogenic causal drivers with available genetic and paleontological techniques. Here, we show that elucidating mechanisms of ancient extinctions can benefit from a detailed understanding of fine-scale metapopulation dynamics, operating over many millennia. Using an abundant fossil record, ancient DNA, and high-resolution simulation models, we untangle the ecological mechanisms and causal drivers that are likely to have been integral in the decline and later extinction of the woolly rhinoceros. Our 52,000-y reconstruction of distribution-wide metapopulation dynamics supports a pathway to extinction that began long before the Holocene, when the combination of cooling temperatures and low but sustained hunting by humans trapped woolly rhinoceroses in suboptimal habitats along the southern edge of their range. Modeling indicates that this ecological trap intensified after the end of the last ice age, preventing colonization of newly formed suitable habitats, weakening stabilizing metapopulation processes, triggering the extinction of the woolly rhinoceros in the early Holocene. Our findings suggest that fragmentation and resultant metapopulation dynamics should be explicitly considered in explanations of late Quaternary megafauna extinctions, sending a clarion call to the fragility of the remaining large-bodied grazers restricted to disjunct fragments of poor-quality habitat due to anthropogenic environmental change.
Fordham, Damien A.; Brown, Stuart C.; Canteri, Elisabetta; Austin, Jeremy J.; Lomolino, Mark V.; Haythorne, Sean; Armstrong, Edward; Bocherens, Hervé; Manica, Andrea; Rey-Iglesia, Alba; Rahbek, Carsten; Nogués-Bravo, David; Lorenzen, Eline D.
52,000 years of woolly rhinoceros population dynamics reveal extinction mechanisms
Proceedings of the National Academy of Sciences 121(24) e2316419121; DOI: 10.1073/pnas.2316419121
© 2024 PNAS.
Reprinted under the terms of s60 of the Copyright, Designs and Patents Act 1988.
Movie S1
Estimates of relative abundance of woolly rhinoceros from the best selected simulations. Red diamonds show location and timing of radiocarbon dated fossils with high-quality dates.
Movie S2
Weighted average habitat suitability from the best selected simulations. Red diamonds show location and timing of radiocarbon dated fossils with high-quality dates.
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