Final answer:
The probability of extinction due to stochastic processes is lower in large populations because random events' impact is diluted, maintaining genetic diversity and population stability.
Step-by-step explanation:
The probability of extinction due to stochastic processes declines as population size increases because random events have less impact on large populations. This is due to the concept of genetic drift, which has a more immediate and significant effect on the gene pool of smaller populations as compared to larger ones.
In small populations, events leading to the death or survival of certain individuals can alter the genetic makeup of the entire group quite drastically. For example, if a natural disaster like a wildfire or hurricane occurs, it may completely eliminate a small population whereas larger populations are more likely to have some survivors that can recolonize. This is sometimes referred to as the bottleneck effect, where a severe decrease in population size can lead to a reduction in genetic variation, which can hamper the ability of the population to adapt to new environmental challenges or diseases. Another related concept is the founder effect, where a new population is started by a small group of individuals, and as a result may have limited genetic variety when compared to the larger original population from which it originated.
Therefore, larger populations tend to have a more robust and stable gene pool, which can absorb the loss of individual variations without much impact on the overall genetic diversity. This diversity is essential for the health and adaptability of the population, making larger populations less susceptible to chance events and sudden genetic shifts.