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 population decline coincides with the end of the last Ice Age, when rapid warming transformed their grassland habitat into forests and tundra, reducing their food supply. Second, genetic studies of ancient mammoth remains show a dramatic loss of genetic diversity just before extinction, indicating population bottlenecks caused by environmental stress, not sudden human predation. Third, archaeological evidence from human sites in Siberia and North America shows only a few mammoth kills, and these occur long after the first humans arrived, suggesting that hunting pressure was too low to cause extinction. Thus, climate-induced habitat loss, not human activity, was the decisive factor.
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The reading’s argument is flawed. While climate change did alter habitats, humans played a far more direct role. First, the timing argument ignores that mammoths survived multiple previous interglacial warm periods, so warming alone cannot explain their final extinction. Instead, the combination of climate stress and increasing human hunting pressure—especially from advanced Clovis hunters—created a synergy that overwhelmed the species. Second, the loss of genetic diversity cited in the reading can be better explained by human-driven fragmentation of populations: as humans expanded, they isolated mammoth herds into small pockets, preventing gene flow and accelerating inbreeding depression. Third, the archaeological record is biased; kill sites are rare because early humans likely used mammoth carcasses for tools and shelter, leaving few butchered remains. Moreover, indirect evidence, such as the development of sophisticated hunting weapons and the rapid extinction of other megafauna on continents where humans arrived, strongly implicates human overhunting. Therefore, while climate contributed, human activity was the decisive cause of the mammoth’s demise.
📝 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.
