TOEFL統合ライティング

📖 読解文章

The collapse of the ancient Mayan civilization in the ninth century AD has long puzzled historians. While various theories exist, recent evidence points to a combination of internal social upheaval and environmental mismanagement as the primary causes. First, deforestation for agriculture and urban expansion led to severe soil erosion and a decline in crop yields. Tree pollen records from lake sediments show a dramatic drop in forest cover between 800 and 900 AD, coinciding with reduced maize production. This agricultural stress likely triggered food shortages and social unrest. Second, prolonged droughts, as reconstructed from stalagmite oxygen isotope data, struck the Yucatan Peninsula repeatedly between 750 and 950 AD. These droughts were severe enough to deplete reservoirs and groundwater, undermining the Mayan's ability to sustain large urban populations. Third, increased warfare among competing city-states, evidenced by fortifications and mass graves, indicates that internal conflict escalated as resources became scarce. This chronic violence disrupted trade networks and agricultural labor, accelerating the civilization's decline.

🎧 リスニング講義

The reading's claims, while plausible, ignore crucial counter-evidence. First, the deforestation theory overstates the impact of Mayan farming. Soil erosion was localized, and the Maya employed terracing and raised-field techniques that conserved soil. Moreover, maize yields may have remained sufficient; the pollen decline could reflect climate-driven vegetation change, not human activity. Second, the drought evidence is ambiguous. Stalagmite records show that droughts, though periodic, were not exceptionally severe compared to earlier centuries when the Maya thrived. More importantly, the Maya had sophisticated water storage systems, including reservoirs and canals, that could buffer against short-term dry spells. The final collapse, however, occurred after a period of increased rainfall, not drought, suggesting water scarcity was not the decisive factor. Third, the warfare interpretation is misleading. The fortifications and mass graves date from a period of political reorganization, but similar evidence exists in earlier eras without collapse. Instead, recent archaeological findings indicate that the collapse was primarily driven by a breakdown in long-distance trade with central Mexico, which deprived the elite of prestige goods and undermined their political authority. This economic disruption, not internal conflict, led to the abandonment of major centers.