Viết tích hợp TOEFL

📖 Đoạn văn

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 the mammoth’s decline correlates more closely with rapid warming at the end of the last Ice Age than with the arrival of human hunters. Fossil records show that mammoth populations peaked during cold periods and collapsed during warm interglacials, even in regions where humans were absent or scarce. Second, the warming climate drastically reduced the mammoth’s preferred habitat—the cold, dry steppe-tundra. Pollen and sediment data indicate that as temperatures rose, this habitat was replaced by forests and wetlands, which were unsuitable for mammoths. This habitat loss would have fragmented populations and reduced food availability, leading to a gradual decline. Third, the mammoth’s biology made it vulnerable to warming. Its thick fur, small ears, and specialized digestive system were adapted to cold, arid conditions. As the climate warmed, heat stress would have impaired reproduction and increased susceptibility to disease, further accelerating extinction. While human hunting may have contributed to the final demise of isolated populations on islands, it cannot explain the widespread extinction that occurred across continents well before humans reached those areas.

🎧 Bài giảng

The reading’s argument that climate change alone drove the woolly mammoth to extinction is unconvincing. First, the timing argument is flawed. While mammoth populations did decline during warm periods, the final extinction events—especially on mainland Siberia and Alaska—coincided precisely with the arrival of advanced human hunters with sophisticated weapons, not merely with warming. For example, mammoths survived on Wrangel Island, where humans arrived late, until about 4,000 years ago, long after the climate had warmed. This suggests that humans, not climate, delivered the final blow. Second, the habitat argument ignores that mammoths were adaptable. Evidence from fossilized dung and teeth shows that during warm periods, they could survive on a broader diet, including shrubs and grasses in mosaic landscapes. Moreover, similar cold-adapted species, such as caribou and musk ox, thrived in the same regions during the same warm period, indicating that habitat changes were not universally fatal. Third, the biological vulnerability claim is overstated. Modern elephants, which are close relatives, tolerate heat well, and mammoth anatomy suggests they had physiological mechanisms to cope with warmer conditions, such as shedding fur and altering fat reserves. The most parsimonious explanation is that human hunting, not climate, was the decisive factor in the mammoth’s extinction.