托福综合写作

📖 阅读文章

The extinction of the woolly mammoth has long been attributed to overhunting by early humans. However, a closer examination of the evidence suggests that climate change was the primary driver. First, the timing of the mammoth's decline coincides with the end of the last Ice Age, when global temperatures rose dramatically. As the ice retreated, the mammoth's preferred habitat—cold, dry steppe—shrunk, reducing food availability. Second, genetic studies of mammoth remains show a significant loss of genetic diversity just before their extinction, indicating a small, stressed population that was already vulnerable, which is more consistent with habitat fragmentation than with sudden human hunting pressure. Third, human populations in the regions where mammoths lived were sparse and their hunting tools, such as spears, were likely insufficient to bring down such large animals, especially given that mammoths had survived alongside humans for thousands of years before their final disappearance.

🎧 听力讲座

The lecture challenges the idea that climate change alone caused the mammoth's extinction. While it is true that temperatures rose, similar warming events had occurred before without causing mammoth extinctions, so climate change alone cannot explain their sudden demise. Instead, the arrival of sophisticated human hunters on the scene is a more plausible cause. Recent archaeological findings at mammoth kill sites show clear evidence of butchery, with stone tools and spear points embedded in bones, proving that humans effectively hunted them. Furthermore, the genetic bottleneck mentioned in the reading is not solely a result of habitat loss; it can also be caused by overhunting, which reduces population numbers rapidly. Finally, human populations at that time were more numerous and organized than the reading suggests, with evidence of mass kill sites where dozens of mammoths were driven off cliffs, indicating that humans had the capability to decimate herds. Thus, the lecture argues that human hunting, not climate, was the decisive factor.