托福综合写作

📖 阅读文章

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 extinction correlates with a period of rapid warming at the end of the last Ice Age, around 10,000 years ago. As temperatures rose, the steppe-tundra habitat that mammoths depended on shrank dramatically, replaced by forests and wetlands. Second, genetic studies of mammoth remains show a severe population bottleneck long before humans arrived in their final refuges, indicating that populations were already declining due to environmental stress. Third, archaeological sites with mammoth kill sites are rare, and when humans did hunt them, they used simple weapons that would have been ineffective against such massive adults. Therefore, climate-induced habitat loss, not human hunting, was the decisive factor in their demise.

🎧 听力讲座

The lecture challenges the reading's claim that climate change alone drove mammoth extinction. While warming did alter habitats, the reading overlooks that mammoths had survived many previous interglacial warm periods without going extinct. What was different this time was the presence of highly skilled human hunters. In fact, recent archaeological discoveries in Siberia reveal mass kill sites with spear points and butchery marks, contradicting the reading's claim of rare hunts. These sites date exactly to the final extinction window, showing humans actively targeted mammoths, possibly driving them into traps. Furthermore, the genetic bottleneck mentioned in the reading actually occurred around 20,000 years ago, during a cold period, but populations recovered before humans arrived; the final decline happened only after human expansion. Thus, the reading misinterprets the evidence: climate stress was not lethal, but human predation was the final push that mammoths could not survive.