The extinction of the woolly mammoth has long been attributed to human overhunting. However, a closer examination of the evidence suggests that climate change was the primary driver of their demise. First, the timeline of mammoth extinction aligns more closely with significant climatic shifts than with human expansion. Radiocarbon dating shows that most mammoth populations disappeared during the rapid warming period at the end of the last Ice Age, around 10,000 years ago, which predates the arrival of large-scale human hunting in many regions. Second, the habitat of woolly mammoths – the mammoth steppe – was highly sensitive to climate. As temperatures rose, this vast grassland was replaced by dense forests and wetlands, which reduced the open grazing areas that mammoths depended on. Fossil pollen records from this period confirm a dramatic vegetation change across Beringia. Third, the genetic diversity of late mammoth populations was already declining before human contact. Studies of ancient DNA reveal that isolated populations suffered from inbreeding and reduced fertility, making them less resilient to any environmental stress. This suggests that internal biological weaknesses, not hunting pressure, sealed their fate.
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The reading argues that climate change was the main cause of woolly mammoth extinction, but this view is flawed. First, the claimed timeline is misleading. While rapid warming occurred around 10,000 years ago, human hunters had already been present in Eurasia and North America for thousands of years, and their hunting pressure intensified exactly as mammoth numbers collapsed. In fact, on islands like Wrangel, where mammoths survived for millennia after the mainland extinction, the climate was similar to the mainland – but no humans arrived, and the mammoths persisted. Second, the vegetation change argument is overstated. Pollen records show that while forests expanded, there were still extensive patches of grassland capable of supporting mammoths. Moreover, mammoths were not strictly grazers; isotopic analyses of their teeth indicate they could browse on shrubs and trees when necessary. Thus, habitat change alone cannot explain their extinction. Third, the genetic evidence is misinterpreted. The low genetic diversity observed in late mammoth populations may have been the result, not the cause, of their decline. Populations that were already shrinking due to hunting would naturally show inbreeding and reduced diversity. In contrast, healthy populations with adequate food and no hunting pressure, like those on Wrangel, maintained stable numbers for thousands of years despite low diversity. Therefore, it was human hunting that initiated the decline, not climate.
📝 Инструкция по письму 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).
