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 coincides with the end of the last Ice Age, when global temperatures rose rapidly. Paleoclimatic data show that their habitat—cold, dry grasslands—shrank dramatically as forests and wetlands expanded. This habitat loss would have reduced food availability and fragmented populations, making them vulnerable to extinction even without human hunting. Second, genetic studies of ancient mammoth remains reveal a significant decline in genetic diversity before their final disappearance. This bottleneck indicates that populations were already stressed and shrinking due to environmental pressures, not because of sudden overhunting. Third, archaeological evidence shows that human hunting of mammoths was relatively rare compared to other prey species. Most human settlements from that period relied on smaller game and plant foods, and mammoth bones found at kill sites are scarce. Thus, while humans may have delivered the final blow, the primary cause was climate-driven habitat change.
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The reading's argument that climate change drove mammoth extinction is flawed. First, while habitat did change, mammoths were highly adaptable. Fossil evidence shows they survived previous interglacial periods with similar warming and habitat shifts. Moreover, their range extended into regions like Wrangel Island, where they persisted for thousands of years after the Ice Age, despite limited grassland. This suggests habitat loss alone was not fatal. Second, the genetic diversity decline cited actually occurred over tens of thousands of years, before the most intense human hunting. But this slow decline is consistent with a gradual population reduction, not a sudden climate event. In fact, the final extinction events on mainland and islands align closely with human arrival times, not with climate fluctuations. For example, mammoths disappeared from mainland Siberia around 10,000 years ago, soon after humans arrived, while they survived on isolated Wrangel Island until 4,000 years ago, when humans also reached it. Third, the claim that human hunting was rare is misleading. Even occasional hunting of megafauna can have outsized impacts on slow-reproducing species like mammoths, which had long gestation periods and low birth rates. Therefore, the evidence better supports human overhunting as the primary cause.
📝 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).
