The giant mammals of the Ice Age may have perished because of a combination of climate change and human hunting. The large animals’ life was cut short by both natural causes and human intervention.
As beloved as they are now, mammoths were just a food source for the first humans on the continent. They lived in the Pliocene epoch just until the Holocene, being contemporary with the mastodons, the sabre-toothed cats, and the giant ground sloths.
The warmer and drier weather was a second factor that contributed to the disappearance of large animals. Researchers think that the modifications in temperature and the changes it brought to the environment made the mammals have difficulties in finding their food and challenged their biological features.
For example, the sabre-toothed cat was a large predator who consumed immense quantities of food. The mammoth was covered with long hair inappropriate for the warm weather. Mastodons were also large animals that fed off grass, leaves and fruits.
The climate change of the Antarctic Cold Reversal meant that the glaciers were retracting, and the vegetation changed. Grasslands were replaced by forests, which triggered the disappearance of all herbivores that could not adapt to the new type of food. Their predators vanished along with them.
The previous theory was that humans who first reached the continent found a world without any large mammals. The new findings show that early humans arrived some 3,000 years before their extinction.
A recent study involved the analysis of mitochondrial DNA taken from 89 samples of fossils. Out of them, 71 bone and teeth remains were tested with radiocarbon dating. Scientists then measured the temperature of ice cores and compared the results.
The collected data showed that the majority of the mammals died almost at the same time, 12,300 years ago. As the first evidence of human activity on the continent was dated to be as old as 14,000 years, the scientists reached the conclusion that our ancestors were witnesses of giant mammals’ extinction, and possibly they might have even contributed to the decrease in their numbers.
As researchers tested fossils of giant mammals found in Patagonia, they managed to discover the first evidence of the human colonization of the two continents. The period of the event was of only 1,500 years.
Paleontologists are trying to understand what kind of human activity led to the mammals’ disappearance. One explanation would be the sudden growth in human population, which increased the need for hunting. Another possibility would be that humans interfered with the giants’ habitat and disrupted their migration.
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