The extinction of the woolly mammoth at the end of the Pleistocene has long been attributed to overhunting by early humans, a hypothesis known as the 'Pleistocene overkill.' Proponents of this view argue that human hunters, equipped with advanced weapons, rapidly decimated mammoth populations as they migrated across continents. First, archaeological evidence at numerous sites, such as the Clovis culture in North America, shows clear signs of mammoth butchery, including cut marks on bones and the presence of spear points in association with remains. Second, the timing of extinction coincides remarkably with human arrival in each region—mammoths disappeared from North America shortly after humans crossed the Bering land bridge, and similar patterns are observed in Eurasia and Australia. Third, mammoths were particularly vulnerable due to their slow reproductive rates: with long gestation periods and single offspring, their populations could not recover from sustained hunting pressure, making them easy targets for human predation.
🎧 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 lecture challenges the overhunting hypothesis, offering alternative explanations for the mammoth's demise. First, while butchery sites exist, they are relatively rare and may represent scavenging of already dead animals rather than active hunting. The number of mammoth bones with human-inflicted marks is far too small to support a mass-kill scenario. Second, the correlation between human arrival and extinction is not consistent. In some regions, such as Wrangel Island, mammoths survived for thousands of years after humans were present, and in parts of Siberia, humans and mammoths coexisted for millennia without immediate extinction. Third, the lecture points to rapid climate change at the end of the last ice age as the primary driver. As temperatures warmed, vegetation shifted from nutritious grasses to less digestible trees and shrubs, reducing mammoth food sources. Moreover, increased rainfall and melting permafrost created boggy terrain that may have caused mammoths to drown or become mired. These environmental stresses, combined with habitat fragmentation, would have severely compromised mammoth populations, independent of human hunting.
📝 ライティング指示 Summarize the points made in the lecture, being sure to explain how they cast doubt on the specific points made in the reading passage.
📊 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).
