Final answer:
Stochasticity in population dynamics refers to the random variation in birth and death rates due to natural disasters and environmental fluctuations. This randomness can significantly impact population size and genetic diversity.
Step-by-step explanation:
Stochasticity refers to the random variation in birth and death rates that occurs in populations from year to year due to natural disasters and other annual variations in the environment.
For example, fluctuations in the environment, such as rainfall and food availability, can affect birth and death rates in populations. Small isolated populations are particularly vulnerable to catastrophic events like floods, fires, droughts, or hurricanes. These events can eliminate local populations, while some individuals may survive and recolonize extensive habitats.
Stochastic processes, or chance events, can also cause genetic drift. For instance, a natural disaster may randomly kill a large portion of a population, leading to a bottleneck effect that reduces genetic variation.