What Animals Went Extinct At The End Of The Ice Age

News Release 11-235

Large Ice-Age Mammal Extinctions: Humans and Climate the Culprits

Findings may foreshadow possible fates of living species

November 2, 2011

This textile is available primarily for archival purposes. Telephone numbers or other contact information may be out of date; please meet electric current contact information at media contacts.

The histories of six large herbivores--the woolly rhinoceros, woolly mammoth, wild equus caballus, reindeer, bison and musk ox--are linked with climate fluctuations and homo activity, peculiarly at the finish of the last ice age, scientists observe in a new report.

Inquiry led by evolutionary biologist Eske Willerslev of the Centre for GeoGenetics at the University of Copenhagen along with an international squad of paleontologists, geologists, geneticists and climate modelers suggests early humans and irresolute climate were responsible for the extinction of some cold-adapted animals, and the most-extinction of others.

The journal Nature published the results of the written report this calendar week. Information technology was the commencement to use genetic, archaeological and climate data to infer the population history of large-bodied ice age mammals.

"The combination of approaches in this study--including the most mod molecular tools and painstaking fieldwork--sheds a powerful low-cal on the circuitous interactions of humans, ecosystems and climate," said Hedy Edmonds, arctic natural sciences program director in the National Science Foundation'due south (NSF) Office of Polar Programs, Sectionalization of Arctic Sciences.

The results carry a message about the possible fates of living mammals as Earth continues to heat up.

"Our findings put a concluding end to single-crusade theories of these extinctions," said Willerslev.

"Our data suggest care should be taken in making generalizations regarding past and present species extinctions," he said. "The relative impacts of climate change and human being encroachment on species extinctions really depend on which species we're looking at."

"We couldn't pinpoint what patterns characterize extinct species, despite the large and varying amount of data analyzed," said scientist Eline Lorenzen of the University of Copenhagen, the outset author of the newspaper.

"This suggests that it will be challenging for experts to predict how existing mammals volition respond to future global climate change--to predict which species volition go extinct and which volition survive."

Beth Shapiro, a biologist at Penn State University whose research for the projection was funded past NSF, explained that all half-dozen of the studied species flourished during the Pleistocene Epoch--the menstruation of geologic time that lasted from about ii million to 12,000 years ago.

"During this time, in that location were lots of climate ups and downs--oscillations betwixt long, warm intervals called interglacial periods, during which the climate was like to what we take today, followed by long, cold intervals called glacial periods, or ice ages.

"Although cold-adapted animals fared better during the colder glacial periods, they still managed to notice places where the climate was just right--refugia--to survive during warmer interglacial periods.

"And so later on the peak of the last ice age around 20,000 years ago, their luck started to run out."

What changed?

To find answers, Shapiro and colleagues tested hypotheses nearly how, when and why the woolly rhinoceros, woolly mammoth and wild horse went extinct later on the last water ice age and why the reindeer, bison and musk ox were able to survive--albeit in more restricted ranges than during the water ice ages.

"1 source of information we used was DNA from the animals themselves," Shapiro said. "With genetic information, information technology's possible to gauge when and how much populations were able to abound and shrink as the climate inverse and their habitat started to disappear."

The scientists also nerveless climate data--temperature and atmospheric precipitation patterns--from both glacial and interglacial periods, also as archaeological data, which they used to study the extent to which early on humans may have influenced the survival of these species.

"For example, in locations where animal bones had been cooked or converted into spears, nosotros know that humans lived at that place and were using these mammals as a resource," Shapiro said.

"Even where we didn't find evidence that humans were using the animals, if they lived in the aforementioned identify and at the same time, humans could take had some influence on whether the animals survived or not."

In the case of the at present-extinct woolly rhinoceros, the scientists constitute that in Europe the ranges of humans and woolly rhinoceros never overlapped.

"These information suggest that climatic change, and not humans, was the primary reason why this particular species went extinct in present-mean solar day Europe," Shapiro said.

"Nosotros wait, though, that humans might have played a part in other regions of the world where they did overlap with woolly rhinos."

Much clearer was the evidence that humans influenced, and not ever negatively, the population sizes of the v other species in the report--the woolly mammoth, wild equus caballus, reindeer, bison and musk ox.

Population fluctuations for all half-dozen species continued until around 14,000 years ago when many of the species simply disappeared at the cease of the terminal ice age.

"The have-home message is that during the most recent warming event, when the last water ice historic period faded into the warm interval we have today, something kept these animals from doing what they had always done, from finding alternative refugia--less-than-platonic, simply good-enough chunks of country on which to keep their populations at a critical mass," Shapiro said.

"That 'something' was probably the states."

During the time when the animals were declining, the human population was beginning its nail, and was spreading out beyond not only the large-bodied mammals' common cold-climate habitats, but across their warm-climate refuges, changing the mural with agronomics and other activities.

Many large-bodied, cold-adjusted mammals, including the horse--which is considered extinct in the wild and now survives simply equally a domesticated beast--of a sudden had no alternative living spaces, and, as such, no means to maintain their populations.

"The results of our study suggest that although past warm periods acquired these creature species to go through periodic bottlenecks--evolutionary events during which the size of a population diminishes substantially and stays pocket-size for a long fourth dimension--they always seemed to bounce back, and to return to their previous habitats as before long equally Earth became libation again," Shapiro said.

"Then, during the about-recent warming cycle, the trend changed."

As the climate became warmer after the last ice age, the woolly rhinoceros, woolly mammoth and wild horse went extinct, but the reindeer, bison and musk ox survived.

Reindeer managed to notice safe habitat in high arctic regions where today they have few predators or competitors for express resources.

Bison are extinct in Asia, where their populations were extensive during the water ice ages, and at present are found just in North America, although a related species survives in small numbers in Europe.

Cold-adjusted musk oxen alive only in the chill regions of North America and Greenland, with small introduced populations in Norway, Siberia and Sweden.

Interestingly, if humans had any impact on musk ox populations, information technology may have been to help sustain them. Musk ox populations kickoff became established in Greenland around 5,000 years agone, after which they expanded rapidly, despite having been a major food resource for the Paleo-Eskimo population.

Today, the species survives in large numbers.

These findings could help predict the fate of mammal populations threatened by present-day climate alter and habitat alteration.

"The results provide direct evidence that something changed between the well-nigh-contempo glacial bicycle, when many of these species went extinct, and previous glacial cycles, through which they all managed to survive," said Shapiro.

"Although it's clear that climate change drives the dynamics of these species, nosotros, as humans, have to take some of the blame for what happened during this most recent cycle."

Our ancestors, information technology seems, were able to change the mural so dramatically, said Shapiro, that these animals were effectively cut off from what they needed to survive, fifty-fifty when the human population was small.

"In that location are many more humans today," she said, "and we have changed, and are continuing to change, the planet in even more important ways."

In improver to Shapiro, Willerslev and Lorenzen, many other scientists contributed to the inquiry. They are from Denmark, Commonwealth of australia, Sweden, Espana, the United Kingdom, holland, Germany, Norway, Russia, Red china, Canada and the Us. U.S. co-authors are from institutions in Utah, California, Texas, Missouri, Maryland, Colorado, Massachusetts, Oregon and Kansas.

The Leverhulme Trust, the Awards Fund, the Danish National Research Foundation, the Lundbeck Foundation and the Danish Council for Independent Enquiry also funded the inquiry.

-NSF-

In their inquiry, scientists looked at ice-age mammal Dna and at long-term climate records.
Credit and Larger Version
Ancient bones, yes, only the tale of extinction they tell may reach into the present.
Credit and Larger Version
While many ice-age mammals went extinct, some are however with us, thriving in northern climes.
Credit and Larger Version
The bones of many large mammals lie earlier scientists, a result of all-encompassing field work.
Credit and Larger Version
Tin can the few ice-historic period mammal species left detect "refugia" in today's warming globe?
Credit and Larger Version

Media Contacts
Cheryl Dybas, NSF, (703) 292-7734, email: cdybas@nsf.gov
Barbara Kennedy, PSU, (814) 863-4682, email: science@psu.edu

The U.Due south. National Science Foundation propels the nation forward by advancing fundamental research in all fields of scientific discipline and engineering. NSF supports research and people by providing facilities, instruments and funding to support their ingenuity and sustain the U.Southward. as a global leader in research and innovation. With a fiscal year 2022 upkeep of $8.8 billion, NSF funds reach all 50 states through grants to nearly 2,000 colleges, universities and institutions. Each yr, NSF receives more 40,000 competitive proposals and makes almost 11,000 new awards. Those awards include support for cooperative enquiry with industry, Arctic and Antarctic research and operations, and U.Due south. participation in international scientific efforts.

mail icon Become News Updates past Email

Connect with us online
NSF website: nsf.gov
NSF News: nsf.gov/news
For News Media: nsf.gov/news/newsroom
Statistics: nsf.gov/statistics/
Awards database: nsf.gov/awardsearch/

Follow us on social
Twitter: twitter.com/NSF and twitter.com/NSFspox
Facebook: facebook.com/US.NSF
Instagram: instagram.com/nsfgov

Source: https://www.nsf.gov/news/news_summ.jsp?cntn_id=122133#:~:text=As%20the%20climate%20became%20warmer,or%20competitors%20for%20limited%20resources.

Posted by: hinesthestrand.blogspot.com