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 correlates with the end of the last Ice Age, when global temperatures rose dramatically. As the climate warmed, the steppe-tundra habitat that mammoths depended on shrank, reducing their food supply and fragmenting their populations. Second, genetic studies show that mammoth populations experienced a severe bottleneck long before humans reached their main habitats in Siberia and North America, indicating that climate-induced stress had already weakened them. Third, archaeological records reveal that early human hunters primarily targeted smaller, easier prey, and mammoth kill sites are rare. Even when humans did hunt mammoths, they likely exploited already weakened individuals. Thus, while human activity may have delivered the final blow, the underlying cause was climate-driven habitat loss and population decline.
🎧 听力讲座
🎯 模拟考试环境：先点「播放讲座」听完内容，再作答。听力原文默认隐藏。
The reading presents a compelling case, but it overlooks key evidence that points to human hunting as the decisive factor. First, the correlation between warming and mammoth decline is not as simple as it seems. Mammoths survived previous interglacial periods with similar warming, so climate alone cannot explain their extinction. Second, the genetic bottleneck cited in the reading actually occurred around 300,000 years ago, far earlier than the late Pleistocene extinction event. This bottleneck was followed by population recovery, meaning the later extinction was not a result of long-term genetic weakness. Third, the claim that humans rarely hunted mammoths is misleading. Recent excavations in Siberia and North America have uncovered numerous mammoth bones with cut marks, spear points embedded in ribs, and even evidence of mass kills at sites like Clovis. These findings demonstrate that humans actively hunted mammoths, and the timing of human expansion into new regions matches exactly with the rapid disappearance of mammoth populations. Therefore, human overhunting, not climate change, was the primary cause of their extinction.
📝 Инструкция по письму Summarize the points made in the lecture, being sure to explain how they cast doubt on the specific points made in the reading passage.
📊 TOEFL Integrated Writing Rubric
Content Accuracy: Accurately capture the relationship between lecture and reading
Information Completeness: Cover all key counter-arguments from the lecture
Structure & Coherence: Logical organization and progression
Language Use: Grammar, vocabulary, expression accuracy
Scored 0-30 based on holistic scoring (original 0-5, scaled to 30).
