Ice Ages

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NYSM Mastodon Mother and Calf Diorama
NYSM Mastodon Mother and Calf Diorama

Ice Age Extinction

At the end of the last Ice Age in North America, about 12,000 years ago, at least 60 species are known to have gone extinct. For the area that is now New York State, this meant the loss of species such as mammoth, mastodon, stag-moose, giant beaver, and giant ground sloth. The extinction coincided with a significant change in climate as well as the colonization of the continent by humans.

For decades, paleontologists have debated what factors were most likely responsible for this extinction event. Here, we explore four of the most prominently suggested factors and the support for or against their role in the extinction.

Climate Change

FOR: Climate change can affect species survival—for example, by changing the food available.

AGAINST: Over the last two million years, the climate has changed from warm to cold about 24 times. These species survived many of those changes.

 

Human Impact

FOR: There is fossil evidence that humans hunted large mammals. Their arrival in North America coincided with the extinction of large mammals.

AGAINST: Other mammals, like bison and white-tailed deer, were also hunted by humans but survived the extinction.

Extraterrestrial Impact

FOR: Scientists discovered sediments at some fossil sites that provide evidence for a comet impact approximately 12,900 years ago, right around the time of the Pleistocene Extinction.

AGAINST: The Pleistocene Extinction affected mostly large animals. A comet impact should affect both large and small animals.

Disease

FOR: Some fossil mammals had diseases, like tuberculosis. Some scientists hypothesize that humans introduced a lethal, highly infectious super-disease that led to the extinction of large mammals.

AGAINST: So far, studies have not identified such a disease.

 

At the time of the Ice Age extinction in the region of present-day New York, both tundra and boreal forest habitats were present suggesting the preferred habitats and food of the Ice Age animals were readily available. Therefore, if food and suitable habitats were relatively stable, it is likely that humans played a significant role in the extinction of these species.