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. First, mammoth populations declined sharply during the Last Glacial Maximum (LGM), around 20,000 years ago, when temperatures dropped dramatically. This cold period reduced the availability of their main food source—grass and sedges—by expanding ice sheets and permafrost, leading to malnutrition and reduced fertility. Second, fossil records show that mammoth habitats shifted northward as the climate warmed after the LGM, but these migrations were too slow to track rapid vegetation changes. Pollen analysis from ancient lake sediments indicates that forests replaced grasslands in many regions, leaving mammoths without suitable foraging grounds. Third, human hunting pressure was likely minimal because human populations were small and scattered during that era. Archaeological sites from the period show that early humans primarily hunted smaller game, such as reindeer and hares, which were easier to capture. Moreover, mammoth bones found at human settlements often show signs of having been scavenged rather than hunted, suggesting that humans only killed mammoths occasionally. Therefore, the combination of extreme cold and vegetation shifts, not human activity, explains the mammoth's demise.

🎧 듣기 강의

The reading's argument that climate change alone caused mammoth extinction is flawed. First, the claim about the LGM is misleading. While temperatures did drop, mammoths had survived similar glacial periods for millions of years. In fact, their populations thrived during earlier cold phases. The real problem emerged only when humans arrived in their habitats, suggesting a causal link. Second, the vegetation shift argument ignores that mammoths were generalist feeders. They could consume shrubs, bark, and even conifer needles when grasses were scarce. Fossilized dung from the period shows a varied diet, contradicting the idea that grassland loss starved them. Third, the reading underestimates human impact. Recent discoveries of spear points embedded in mammoth ribs and butchery marks on bones indicate active hunting. Moreover, human populations were larger and more organized than previously thought, with evidence of coordinated drives and traps. Even if hunting was occasional, selective targeting of young and females would have devastated populations, especially since mammoths had slow reproductive rates. In summary, overhunting—not climate—was the decisive factor, as humans arrived just before the final extinction wave.