TOEFL Integrated Writing

📖 Reading Passage

The extinction of the woolly mammoth, a species that roamed the northern hemisphere during the Pleistocene, has long been attributed to human overhunting. This 'Pleistocene overkill' hypothesis is supported by several lines of evidence. First, archaeological sites across North America and Eurasia contain numerous mammoth bones with cut marks and embedded projectile points, indicating that early humans actively hunted these animals. Second, the timing of mammoth extinctions correlates with the arrival of human populations on different continents; for instance, mammoths disappeared from North America shortly after the Clovis people appeared around 13,000 years ago. Third, modeling studies suggest that even a modest human population, with a low hunting rate, could drive a slow-reproducing species like the mammoth to extinction within a few thousand years. These factors collectively point to human hunting as the primary driver of the mammoth's demise.

🎧 Listening Lecture

While the reading makes a case for human overhunting, the lecture presents a compelling counter-argument, suggesting that climate change was the decisive factor. First, the evidence of hunting is ambiguous: many mammoth bones with cut marks may have been scavenged from animals that died of natural causes, and the number of such sites is too sparse to support a sustained hunting pressure that would cause extinction. Second, the correlation between human arrival and mammoth extinction is not consistent; in some regions, such as Wrangel Island, mammoths survived for thousands of years after humans arrived, whereas in others, they disappeared before any human presence. Third, recent climate data reveal that the Late Pleistocene experienced dramatic and rapid temperature fluctuations and vegetation shifts, which would have drastically reduced the mammoth's preferred grassland habitats. Climate models show that these changes alone could have fragmented and shrunk mammoth populations, making them more vulnerable to extinction, regardless of human activity. Thus, the lecture argues that the species' decline was primarily a consequence of environmental change, not human hunting.