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 disappearance. First, the timing of mammoth extinctions correlates more strongly with climatic shifts than with human expansion. Radiocarbon dating shows that most mammoth populations vanished during the rapid warming period known as the Bølling-Allerød interstadial, around 14,000 years ago, which predates the widespread arrival of human hunters in many regions. Second, mammoths were highly adapted to cold, dry steppe environments. As the climate warmed and became wetter, their preferred habitat—the mammoth steppe—was replaced by forests and peatlands, drastically reducing their food sources and migratory corridors. Fossil pollen records from this period confirm a rapid vegetation change. Third, mammoths had low reproductive rates, with long gestation periods and small litter sizes. This made them particularly vulnerable to environmental stress, as population recovery from even modest increases in mortality or decreases in food availability would have been extremely slow. In contrast, human hunting pressure, while present, was likely too localized and sporadic to have caused a global extinction event, especially given that mammoth populations had survived millennia of coexistence with hominins in Africa and Eurasia.
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The reading's claim that climate change alone drove woolly mammoth extinction is unconvincing. While climate shifts did occur, they do not explain the pattern of extinction. First, the correlation with warming is misleading. Mammoths survived previous interglacial periods with similar warming, such as the Eemian, about 120,000 years ago. The key difference in the late Pleistocene was the presence of highly effective human hunters, who used sophisticated weapons and drove mammoths into traps. Second, although habitat changed, mammoths were not as inflexible as the reading suggests. Fossil evidence shows they could adapt to a variety of environments, including boreal forests and grasslands. Moreover, their extinction occurred on continents but not on isolated islands like Wrangel Island, where humans arrived much later—this supports the human role. Third, low reproductive rates would have made mammoths vulnerable to any added pressure, including hunting. Even moderate hunting by humans, combined with climate stress, could have pushed populations over the edge, especially since humans selectively targeted juveniles and females. Thus, the reading overlooks the synergistic effect of human hunting and climate change, with humans as the decisive factor.
📝 Hướng dẫn viết 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).
