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 extinctions correlates with the end of the last Ice Age, when temperatures rose rapidly. As glaciers retreated, the steppe-tundra habitat that mammoths depended on shrank dramatically, replaced by forests and wetlands. Pollen records from this period show a sharp decline in grasses and sedges, the mammoth’s main food sources. Second, human populations at the time were sparse and lacked advanced hunting technology. Archaeological sites from the era contain few mammoth remains with cut marks, indicating that hunting was occasional rather than systematic. In contrast, climate models show that warming would have stressed mammoth populations by reducing their nutritional intake and increasing heat stress, particularly for large-bodied animals. Third, isolated populations on islands, such as Wrangel Island, survived until around 4,000 years ago, long after humans had arrived on the mainland but before the island’s vegetation shifted to dwarf shrubs. This suggests that habitat change, not hunting, was the decisive factor. Therefore, the woolly mammoth’s demise was a consequence of natural climate dynamics, not human predation.
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The reading’s argument that climate change alone drove the woolly mammoth to extinction is not convincing. While it is true that warming altered habitats, this does not rule out a major role for human hunting. First, the correlation between warming and extinction is too broad. Mammoths survived several previous interglacial periods with similar temperature rises, so climate change alone cannot explain their final disappearance. In contrast, the last extinction event coincides precisely with the expansion of modern humans into new continents. Second, the claim that humans lacked advanced hunting technology is misleading. Even simple spears and driving tactics could be effective against young or weakened mammoths. Recent excavations in North America and Siberia have revealed kill sites with multiple mammoth skeletons and associated stone tools, indicating coordinated hunting. Moreover, the scarcity of cut marks may reflect that humans used mammoth carcasses for non-food purposes, such as building materials, which would leave few traces. Third, the Wrangel Island example actually supports the hunting hypothesis. When humans first arrived on Wrangel around 3,700 years ago, the island still had suitable vegetation, but the mammoth population vanished within a few centuries. Genetic studies show that the final population was small and inbred, making them especially vulnerable to even low levels of hunting pressure. Thus, human predation was likely the coup de grâce that finished off a species already stressed by climatic changes.
📝 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.
