Final answer:
Changes in population size can be influenced by various environmental and biological factors, such as diseases, food availability, climate change, reproductive rates, and immigration or emigration patterns, which can either increase or decrease a population from generation to generation.
Step-by-step explanation:
The factors that can cause a change in the size of a population from one generation to the next include diseases, predators, and natural disasters, such as wildfires and hurricanes, which can drastically decrease population size. On the other hand, availability of food resources, climate changes, and habitat destruction can either increase or decrease a population size, depending on how these factors alter the habitat or resources. Other important aspects include the reproductive rates within the population, which directly influence population growth, and immigration and emigration patterns, which alter the size by moving individuals in or out of populations.
Populations are dynamic, and their size can fluctuate greatly in response to these and other factors. For example, density-dependent factors such as competition for food can significantly impact population size based on the current population density. In contrast, density-independent factors like natural disasters can affect populations regardless of their size.