The extinction of the woolly mammoth has long been attributed to human overhunting. However, recent evidence suggests that climate change was the primary driver. First, the timing of mammoth decline coincides with the end of the last Ice Age, when global temperatures rose rapidly. This warming led to the replacement of open grasslands—the mammoth’s main food source—with dense forests and tundra, reducing their habitat and food availability. Second, genetic studies of fossil remains show a significant loss of genetic diversity in mammoth populations thousands of years before human hunters arrived in their habitats. This bottleneck indicates that populations were already shrinking due to environmental stress, not sudden human predation. Third, archaeological evidence reveals that early human settlements primarily hunted smaller game, such as deer and rabbits, which were easier to capture. Mammoth bones are rarely found at these sites, suggesting that humans did not rely on mammoths as a staple food. Therefore, the extinction of the woolly mammoth was most likely caused by climate-driven habitat loss, not human overhunting.
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The reading’s argument that climate change alone drove mammoth extinction is flawed. While warming did alter vegetation, the transition was not abrupt; mammoths had survived previous interglacial periods with similar warming. What was different this time was the presence of highly skilled human hunters. First, the timing argument is misleading. Human hunters arrived in North America and Eurasia at exactly the same time as the final mammoth decline—around 10,000 to 12,000 years ago. In contrast, earlier climate shifts did not cause extinction because no humans were present. Second, the genetic bottleneck cited in the reading actually supports human involvement. A rapid population crash, consistent with overhunting, would also reduce genetic diversity. Moreover, the loss of diversity occurred precisely when human hunting expanded, not millennia earlier. Third, the archaeological evidence is incomplete. Mammoth bones may be scarce at campsites because hunters often butchered large animals at kill sites, leaving carcasses where they fell. In fact, several sites show mammoth bones with cut marks and spear points embedded, indicating active hunting. Thus, the reading underestimates the role of humans and misinterprets the evidence.
📝 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).
