The extinction of the woolly mammoth has long been attributed to human overhunting, but a closer examination of the evidence suggests that climate change was the primary driver. First, the timing of the mammoth’s decline correlates more strongly with climatic shifts than with human expansion. Radiocarbon dating shows that mammoth populations began to dwindle around 15,000 years ago, during a period of rapid warming, while human hunters did not arrive in many mammoth habitats until several thousand years later. Second, the geographic pattern of extinction supports a climate-based explanation. Mammoths survived on remote islands, such as Wrangel Island, until 4,000 years ago, despite the presence of humans on nearby continents. This suggests that isolation from climate-driven habitat changes, not human hunting, allowed these populations to persist. Third, the dietary habits of mammoths make them vulnerable to climate change. As obligate grazers, they depended on cold, dry steppe grasslands, which were replaced by forests and wetlands during warmer, wetter periods. This vegetation shift would have drastically reduced their food supply, leading to malnutrition and population decline, whereas human hunting would have had a more uniform impact regardless of habitat type.
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The reading’s argument that climate change alone drove mammoth extinction is compelling, but it overlooks key evidence that human hunting played a decisive role. First, while it is true that mammoth numbers decreased during warming periods, this does not rule out hunting. In fact, human populations also expanded during these warmer intervals, and archaeological sites show that humans actively hunted mammoths, using their bones for shelter and tools. The correlation with climate may simply reflect that humans were more able to hunt in warmer conditions. Second, the survival of mammoths on Wrangel Island actually supports the hunting hypothesis. These island populations were small and isolated, and humans did not reach the island until after their extinction. This suggests that where humans did not arrive, mammoths thrived, which directly implicates hunting on mainlands. Third, the dietary argument is flawed. Mammoths were not strictly grazers; isotopic analyses of their teeth reveal that they also consumed shrubs and tree leaves. This flexibility would have allowed them to adapt to changing vegetation, meaning climate-induced starvation was unlikely. Instead, the sudden disappearance of mammoths in each region coincides with the arrival of sophisticated human hunters, a pattern that is hard to explain by climate alone.
📝 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.
