### Mammoth Population Decline
Scientists debate the primary cause of the woolly mammoth’s extinction at the end of the Pleistocene epoch.
Hypothesis 1
The extinction was driven by rapid climate warming, which altered the vegetation of the mammoth's habitat. The dry, grassy steppe-tundra transitioned into wet, nutrient-poor shrublands and forests, which could not support the dietary needs of large herbivores like mammoths.
Hypothesis 2
The extinction was caused by human overhunting. As human populations expanded across northern regions, their advanced hunting tools and strategies allowed them to hunt mammoths at rates far exceeding the species' natural reproduction rates, driving them to extinction.
New Evidence
Researchers analyzed woolly mammoth fossils and plant pollen from sediment layers on a remote Siberian island. They found that a major decline in the mammoth population occurred over a -year period during which grass pollen levels dropped by and shrub pollen levels increased. The earliest human artifacts on the island date to years after the mammoth population had already completely disappeared.
Based on this new evidence, which of the following statements best describes the impact of the findings on the two hypotheses?
- AThe evidence undermines the climate-driven vegetation change explanation while strengthening the human overhunting explanation.
- BThe evidence supports both the climate-driven vegetation change explanation and the human overhunting explanation.
- The evidence strengthens the climate-driven vegetation change explanation while undermining the human overhunting explanation.Cevap
- DThe evidence has no effect on the climate-driven vegetation change explanation but weakens the human overhunting explanation.