The extinction of the woolly mammoth has long been attributed to human overhunting, but recent evidence suggests that climate change was the primary driver. First, the timing of mammoth decline coincides with the rapid warming at the end of the Pleistocene, around 10,000 years ago. As forests expanded and grasslands shrank, mammoths lost their preferred habitat. Second, genetic studies show that mammoth populations experienced a severe bottleneck before human populations reached peak hunting pressure. This indicates that climate-induced habitat fragmentation reduced their numbers well before widespread hunting. Third, on isolated islands like Wrangel Island, mammoths survived for thousands of years after human arrival, but eventually disappeared when sea levels rose and reduced their range. This pattern is inconsistent with overhunting, which would have caused rapid extinction soon after human contact.
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The reading's claim that climate change alone explains mammoth extinction is flawed. First, while warming did alter habitats, similar warming events had occurred during previous interglacial periods, yet mammoths survived those changes. The only unique factor in the late Pleistocene was the arrival of highly skilled human hunters. Second, the genetic bottleneck cited in the reading actually supports the opposite view: the small, isolated populations that remained were highly vulnerable to hunting pressure. Even a modest level of hunting could have pushed these fragile groups over the edge. Third, the Wrangel Island case is misleading. Mammoths there survived because the island was remote and initially lacked human presence. When humans finally reached Wrangel, they rapidly drove the mammoths to extinction within a few centuries, a pattern consistent with overhunting. Thus, the evidence points to humans as the decisive factor.
📝 写作提示 Summarize the points made in the lecture, being sure to explain how they cast doubt on the specific points made in the reading passage.
