Viết tích hợp TOEFL

📖 Đoạn văn

The extinction of the woolly mammoth, which occurred approximately 4,000 years ago, has long been attributed primarily to human overhunting. However, recent evidence points to a more complex scenario involving climate change and other factors. Three main arguments support the idea that climate change, not human activity, was the decisive cause. First, the timing of the mammoth’s disappearance aligns closely with a major climatic shift known as the Younger Dryas, a period of abrupt cooling that drastically altered vegetation. Mammoths relied on open grasslands for food, but as temperatures dropped, these grasslands were replaced by tundra and forests, reducing their habitat and food supply. Second, human populations during this era were sparse and lacked the sophisticated hunting technology needed to bring down such large animals. Archaeological sites from the period show only simple stone tools and no clear evidence of mass kill sites or butchering of mammoths on a scale sufficient to cause extinction. Third, similar megafauna species, such as the giant ground sloth and the saber-toothed cat, also went extinct during the same period across different continents, even in regions where human presence was minimal or absent. This global pattern strongly suggests that a common environmental cause, namely climate change, was responsible, rather than localized human hunting.

🎧 Bài giảng

The professor challenges the reading’s claim that climate change was the primary cause of the woolly mammoth’s extinction. While climate shifts did occur, they were not as catastrophic as the reading suggests. For example, during the Younger Dryas, some regions actually experienced milder conditions that supported grasslands, and mammoth populations persisted in these refugia. The extinction happened when humans arrived in these last refuges, such as Wrangel Island, where mammoths survived until 4,000 years ago—long after the climate had stabilized. This island was too small to support a large human population, but even a few hunters could have driven the small, isolated mammoth population to extinction. Second, the claim that humans lacked the technology is misleading. Evidence from sites in North America and Siberia shows that early humans used spear points and drove mammoths into bogs or traps, leading to successful kills. Moreover, the absence of mass kill sites does not rule out hunting; humans may have hunted young or weakened individuals, which would leave fewer archaeological traces. Finally, the global extinction pattern is not as uniform as the reading claims. In Africa and southern Asia, where humans evolved and had longer contact with megafauna, many large animals survived, whereas in the Americas and Australia, where humans arrived relatively recently, extinctions were severe and rapid. This pattern aligns more with human arrival than with climate changes, which varied regionally. Therefore, the lecture argues that human hunting, perhaps combined with environmental stress, was the more likely decisive factor.