The extinction of the woolly mammoth has long been attributed to overhunting by early humans, but recent evidence suggests that climate change was the primary driver. First, the warming period at the end of the Pleistocene reduced the mammoth's grassland habitat. Fossil pollen records show that vast steppe-tundra ecosystems were replaced by forests and wetlands, which were unsuitable for large grazing herds. Second, the timing of extinction correlates with rapid climatic shifts, not human expansion. In Siberia, mammoth populations survived until about 4,000 years ago on Wrangel Island, long after humans had arrived in the region, but this population vanished shortly after a period of dramatic sea-level rise and vegetation change. Third, genetic studies indicate that the final populations suffered from inbreeding and reduced genetic diversity, a classic sign of environmental stress rather than direct hunting pressure. These lines of evidence collectively point to climate-driven habitat loss as the decisive factor in the mammoth's demise.
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The reading's claim that climate change alone killed the woolly mammoth is oversimplified. While habitat shifts were significant, human hunting played a more direct role than the reading acknowledges. First, archaeological sites with mammoth bones show clear cut marks and spear points, particularly in North America and Eurasia, dating to the exact period of extinction. These tools and butchery marks are not found in earlier warm intervals when mammoths also faced habitat changes but did not go extinct. Second, the survival on Wrangel Island actually supports the hunting hypothesis: this island was isolated and inaccessible to humans for thousands of years, allowing a small population to persist. When sea ice formed during cold snaps, humans could cross, and the mammoths disappeared within a few centuries of human arrival—not merely after climate shifts. Third, genetic inbreeding is not evidence against hunting; in fact, small, shrinking populations—whether from hunting or habitat loss—would show similar genetic patterns. However, the rapid extinction on Wrangel, within a human timeframe, is more consistent with overhunting than with slow climate-driven decline. Thus, while climate contributed, human predation was the final, decisive push.
📝 คำแนะนำการเขียน 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).
