TOEFL Integrated Writing

📖 Reading Passage

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 disappearance correlates closely with a period of rapid warming known as the Bolling-Allerod interstadial, around 14,000 years ago. As temperatures rose, the open grasslands that mammoths depended on were replaced by dense forests and tundra, reducing their food supply. Second, genetic studies show that mammoth populations experienced a severe decline in genetic diversity before their final extinction, indicating that they were already vulnerable due to shrinking habitats, not sudden human pressure. Third, archaeological sites from the period show that human hunting of mammoths was relatively rare; most settlements relied on smaller game and fish, and the few mammoth bones found with cut marks are often from already dead animals, suggesting scavenging rather than active hunting. Thus, while humans may have delivered a final blow, climate-driven habitat loss was the fundamental cause of the mammoth’s demise.

🎧 Listening Lecture

The lecture challenges the reading’s claim that climate change, not human hunting, drove the mammoth to extinction. While the warming period did alter vegetation, the reading overlooks that mammoths survived previous interstadials with similar warming, so climate alone cannot explain their final extinction. Moreover, the genetic diversity decline cited actually began long before the Bolling-Allerod, and it was gradual, not a crash. This decline made mammoths more vulnerable to any stress, including hunting. The reading also downplays human impact by citing rare cut marks, but that evidence is misleading: early humans likely used mammoth carcasses for meat and hides, yet they may not have left cut marks on bones if they processed meat away from kill sites. In fact, recent excavations in Siberia have revealed mass kill sites with spear points embedded in mammoth ribs, proving active hunting. Finally, the lecture points out that the final extinction occurred during a cold snap, not a warm period, contradicting the idea that warming was the key factor. Therefore, the reading’s argument is flawed; human hunting was a decisive factor, especially on already stressed populations.