Question

Which one of the following sets of characteristics is most likely to cause population extinction via demographic stochasticity?

• A. Small geographical range and low population density
• B. Large geographical range and low population density
• C. Small geographical range and high population density
• D. Large geographical range and high population density

Hint:

Demographic stochasticity has a greater impact on populations with smaller sizes and restricted ranges.

Answer 1

The Correct Option is A

Step 1: Understand demographic stochasticity.
Demographic stochasticity refers to the random fluctuations in population size and growth due to the random nature of reproduction and survival at the individual level. Populations with small geographical ranges and low population densities are more vulnerable to these fluctuations, making them more likely to face extinction.

Step 2: Evaluate each option.
Option (A): Correct, small range and low population density increase vulnerability to extinction via demographic stochasticity.
Option (B): Larger ranges can reduce vulnerability by allowing for a larger population, even if density is low.
Option (C): High population density can buffer against demographic stochasticity, making this option less likely to cause extinction.
Option (D): Large range and high density would typically protect against stochastic extinction.
Hence, the correct answer is (A).