TOEFL 통합 작문

📖 읽기 지문

The extinction of the woolly mammoth has long been attributed to overhunting by early humans. However, recent evidence suggests that climate change was the primary driver of their demise. First, paleoclimatic data indicate that the warming period at the end of the Pleistocene dramatically altered mammoth habitats. As temperatures rose, grasslands—the mammoths’ primary food source—were replaced by forests and tundra, reducing their foraging grounds. Second, genetic studies of mammoth remains show a significant decline in genetic diversity before human populations expanded in their range. This suggests that mammoth populations were already fragmented and stressed due to environmental shifts, making them vulnerable to extinction even without hunting. Third, the timing of mammoth extinctions in different regions correlates more closely with vegetation changes than with human arrival. For example, on Wrangel Island, where mammoths survived until 4,000 years ago, human presence was minimal, yet the population finally collapsed when climate-driven vegetation shifts reduced their food supply. Therefore, the primary cause of mammoth extinction was climate-induced habitat loss, not human overhunting.

🎧 듣기 강의

The reading presents a compelling argument for climate change as the main cause of mammoth extinction, but it overlooks several critical points. First, while it is true that grasslands declined during warming periods, this does not rule out human hunting. In fact, archaeological sites show that mammoth bones with cut marks from human tools coincide with peak warming periods, indicating that humans actively hunted the remaining mammoths as they became concentrated in shrinking habitats. Second, the claim of low genetic diversity before human expansion is misleading. Low diversity can be a natural result of small populations, but it does not explain why mammoths survived previous interglacial warm periods with similar low diversity. Only when humans arrived did populations crash completely, suggesting hunting was the decisive factor. Third, the case of Wrangel Island actually undermines the climate argument. The island's vegetation remained suitable for mammoths until about 4,000 years ago, yet they went extinct shortly after the first evidence of human settlement on the island. This timing strongly implicates human activity, not gradual climate change. Thus, while climate may have stressed mammoth populations, it was human hunting that delivered the final blow.