Based on the population estimates provided in the chart for the years 1990 and 2000, let's analyze the data and work toward selecting the best-supported explanation.
The population sizes of Cheetahs and Zebras in 1990 and 2000 are presented below:
- Cheetahs (1990): 100,000
- Cheetahs (2000): 47,000
- Zebras (1990): 50,000
- Zebras (2000): 7,500
### Step-by-Step Analysis:
1. Decline in Cheetah Population:
- Population in 1990: 100,000
- Population in 2000: 47,000
- Decline: \(100,000 - 47,000 = 53,000\)
2. Decline in Zebra Population:
- Population in 1990: 50,000
- Population in 2000: 7,500
- Decline: \(50,000 - 7,500 = 42,500\)
3. Correlation:
- The data shows a significant decline in both cheetah and zebra populations over the decade.
- The decline of cheetahs by 53,000 individuals and zebras by 42,500 individuals suggests a possible link between the reduction in zebras, a primary food source, and the decline in predator populations, such as cheetahs.
### Explanation Supported by Data:
Given the significant parallel decline in both cheetah and zebra populations, the best-supported explanation by the numbers would be:
- The dwindling zebra population has led to the decline of the predator lion and cheetah populations.
This explanation indicates that the reduction in the zebra population, which is a food source for predators like cheetahs (and potentially lions too), has likely contributed to the observed decline in the predator populations due to a decrease in available prey.
