Final answer:
The Pleistocene Extinction led to the loss of many megafauna about 10,000-12,000 years ago, likely due to over-hunting by humans. The timing of these extinctions correlates with the arrival of humans rather than climate changes, suggesting human activities played a significant role in these occurrences.
Step-by-step explanation:
The Pleistocene Extinction and Megafauna Loss
The Pleistocene Extinction, also called the Quaternary or Holocene extinction, was a period marked by the disappearance of many large mammals, or megafauna, from various parts of the world. This mass extinction event saw the loss of species such as the woolly mammoth, mastodon, giant beavers, and saber-toothed cats. It is believed that this happened 10,000-12,000 years ago, toward the end of the last glaciation period.
One leading hypothesis for the extinction of the megafauna is the impact of human activities, specifically over-hunting. Research suggests that the timing of the extinctions correlates with the arrival of humans in different regions, such as Australia, North America, and numerous remote oceanic islands. In contrast, regions like Eurasia and Africa, where humans had been present for a much longer time, do not show the same patterns of extinction. This may suggest that recent arrivals of human populations are linked to significant ecological impacts and species extinctions.
Although climate change is another hypothesis considered for these extinctions, evidence often points toward human hunting as a precipitating factor. It's noted that in several cases, the arrival of human hunters corresponds with the timing of these extinction events. As such, this topic remains an active area of research to understand human impacts on environmental changes and extinctions.