Viết tích hợp TOEFL

📖 Đoạn văn

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 timing of the mammoth’s decline coincides with the warming period at the end of the last Ice Age, not with human migration patterns. Radiocarbon dating shows that mammoth populations began to shrink dramatically around 12,000 years ago, when temperatures rose and vegetation shifted from cold-adapted grasses to forests and tundra shrubs, which were less nutritious for these large herbivores. Second, mammoths had specialized adaptations—thick fur, small ears, and a high-fat hump—that made them suited for cold environments. As the climate warmed, these adaptations became disadvantageous, leading to heat stress and reduced fertility. Third, human hunting pressure was likely minimal because mammoth populations were already sparse and widely dispersed by the time humans reached their habitats. Archaeological sites from this period contain few mammoth remains, and the tools found are more consistent with processing smaller game. Therefore, climate-driven habitat change, not human predation, was the decisive factor in the mammoth’s disappearance.

🎧 Bài giảng

The lecture challenges the reading’s claim that climate change alone drove the woolly mammoth to extinction. While it is true that warming occurred, the timing does not support a simple climate cause. In fact, mammoths survived for thousands of years after the initial warming, persisting on isolated islands like Wrangel Island until about 4,000 years ago, long after the climate had stabilized. This suggests that factors other than temperature, such as human arrival, were crucial. Second, the reading’s argument about dietary changes ignores the fact that mammoths were generalist feeders. Fossilized stomach contents show they consumed a wide variety of plants, including shrubs and herbs, which were available even in warmer periods. Thus, food scarcity was not a fatal issue. Third, the archaeological evidence is more nuanced than the reading suggests. Recent excavations have uncovered mammoth bones with clear cut marks and embedded spear points, indicating active hunting. Moreover, human populations expanded exactly when mammoth populations crashed on the mainland, and the last surviving populations were on islands where humans arrived late. This correlation strongly implicates human overhunting as the primary cause, not climate change.