The extinction of the mammoth, a massive prehistoric relative of the elephant, has long puzzled scientists. While some argue that human hunting was the primary cause, a closer examination of the evidence suggests that climate change was the decisive factor. First, the timing of mammoth extinctions correlates strongly with major climatic shifts. Most mammoth populations disappeared during the Late Pleistocene, a period marked by dramatic warming and the retreat of glaciers. As temperatures rose, their cold-adapted habitat—steppe tundra—shrank significantly, reducing their food supply and leading to population declines long before humans arrived in many regions. Second, the geographic pattern of extinction supports a climate-driven explanation. Mammoths survived on remote islands, such as Wrangel Island, until around 2000 BCE, even though humans had reached the mainland much earlier. If hunting were the primary driver, these isolated populations would have been even more vulnerable to human hunters, yet they persisted for thousands of years after mainland extinctions. Third, archaeological evidence shows that early human hunting techniques were not efficient enough to wipe out such a wide-ranging species. Spear points and other tools from that era were relatively crude, and human populations were sparse. Modern simulations of hunter-gatherer hunting suggest that even with optimal strategies, they could not have killed enough mammoths to cause extinction across continents, especially given the mammoths’ large size and slow reproductive rates.
🎧 听力讲座
🎯 模拟考试环境：先点「播放讲座」听完内容，再作答。听力原文默认隐藏。
The reading claims that climate change, not human hunting, drove mammoth extinction, but this view is flawed. First, while climate shifts occurred, similar warming events had happened earlier in the Pleistocene, and mammoths survived them. The key difference in the Late Pleistocene was the presence of advanced human hunters. In North America, for instance, mammoth remains are found alongside Clovis spear points, and kill sites show clear evidence of butchering, indicating humans actively hunted these animals. Second, the island survival argument actually supports human hunting as the main cause. Wrangel Island mammoths survived because they were isolated from humans until about 2000 BCE. When humans finally arrived, the mammoths disappeared within a few centuries—a pattern consistent with overhunting, not climate, since the climate on Wrangel Island remained stable during that brief period. Third, the claim that human tools were ineffective is misleading. While individual spear points were simple, hunters used coordinated strategies, such as driving herds off cliffs or into bogs, as evidenced by mass kill sites with dozens of mammoth skeletons. Moreover, even low hunting pressure could have been devastating because mammoths had very slow reproductive rates—females gave birth every few years—so any additional mortality from hunting would have tipped populations into decline. Thus, the evidence strongly implicates humans as the primary agents of extinction.
📝 Writing Prompt Summarize the points made in the lecture, being sure to explain how they cast doubt on the specific points made in the reading passage.
📊 TOEFL Integrated Writing Rubric
Content Accuracy: Accurately capture the relationship between lecture and reading
Information Completeness: Cover all key counter-arguments from the lecture
Structure & Coherence: Logical organization and progression
Language Use: Grammar, vocabulary, expression accuracy
Scored 0-30 based on holistic scoring (original 0-5, scaled to 30).
