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 disappearances correlates closely 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—shrank, replaced by forests and wetlands that were unsuitable for their grazing lifestyle. Second, genetic studies of mammoth remains show a significant decline in genetic diversity thousands of years before human populations expanded into their ranges. This bottleneck indicates that populations were already stressed by environmental changes, making them vulnerable to extinction even without human interference. Third, archaeological sites from the period show that humans primarily hunted smaller game and gathered plants, not large megafauna. Isotopic analysis of human bones from the era reveals a diet dominated by fish and small mammals, suggesting that mammoth hunting was rare and unlikely to have caused a continent-wide extinction. Therefore, while humans may have contributed locally, the overwhelming evidence points to climate-driven habitat loss as the main cause of the woolly mammoth's demise.
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The reading's claim that climate change drove the woolly mammoth to extinction is flawed. While it is true that temperatures rose, the mammoth did not simply disappear with the ice—it survived for thousands of years in isolated pockets, such as on Wrangel Island, where the climate was indeed colder. This survival contradicts the idea that warming alone was fatal. Moreover, the genetic bottleneck the reading mentions actually supports the overhunting hypothesis: as human hunters killed off individuals in core populations, the remaining small groups became inbred, leading to a loss of diversity. This pattern matches predictions of human-driven extinction, not gradual climate change. Finally, the dietary evidence from human bones is misleading. Isotopic analysis of bones from sites where mammoth bones are abundant shows that humans did consume mammoth meat, and stone tools found alongside mammoth remains display cut marks consistent with butchering. The fact that humans also ate smaller game does not rule out their role in driving megafauna to extinction—hunters often target the largest, most vulnerable animals first. Thus, the reading overlooks direct evidence of human hunting and misinterprets the genetic and dietary data.
📝 Hướng dẫn viết 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).
