Escritura integrada TOEFL

📖 Texto de lectura

The extinction of the woolly mammoth has long been attributed to human overhunting, but a closer examination of the evidence suggests that climate change was the primary driver. First, the timing of the mammoth’s disappearance aligns more closely with the end of the last Ice Age, when rapid warming transformed the Siberian and North American landscapes. As temperatures rose, the dry, grassy steppe that mammoths depended on was replaced by wetter, forested tundra, reducing their primary food source. Second, genetic studies of ancient mammoth remains show a significant decline in population size long before humans arrived in their habitats. This pre-human bottleneck indicates that environmental pressures were already causing severe stress, making it unlikely that hunting alone could have delivered the final blow. Third, archaeological evidence does not support the overkill hypothesis: the number of mammoth kill sites is surprisingly small, and many human settlements from that era show little evidence of mammoth consumption. In contrast, the fossil record reveals that mammoth populations fluctuated with past climatic shifts, thriving during cold, dry periods and shrinking during warm, wet intervals. Therefore, while humans may have contributed to the extinction in some regions, the overwhelming evidence points to climate-driven habitat loss as the decisive factor.

🎧 Conferencia de audio

The reading’s argument that climate change, rather than human hunting, drove the woolly mammoth to extinction is not convincing. First, the timing argument is flawed. While the last Ice Age ended about 10,000 years ago, mammoths survived on isolated islands like Wrangel Island until 4,000 years ago, long after the climate had stabilized. This suggests that climate change alone cannot explain their final extinction; instead, the arrival of humans on these islands correlates with their demise. Second, the genetic evidence cited in the reading is misinterpreted. The pre-human population decline may reflect natural fluctuations, but it does not prove that mammoths could not recover. Indeed, populations did rebound in some areas before humans appeared, indicating that they could withstand climate shifts. What they could not withstand was the combination of climate stress and hunting pressure. Third, the archaeological evidence is more robust than the reading claims. New excavations have uncovered numerous mammoth kill sites with butchery marks, and isotope analyses of human bones from that period show a high proportion of mammoth protein in their diets. Furthermore, the lack of kill sites may simply reflect the fact that early humans used every part of the carcass, leaving few remains behind. In sum, when we consider the full body of evidence, human hunting was likely the critical factor that pushed an already vulnerable species over the edge.