What term refers to the number of individuals moving into an existing population?

The term that describes the number of individuals moving into an existing population is immigration. This process involves organisms entering a new habitat or area, contributing to the growth of an existing population. Immigration can affect population size and dynamics by bringing in new genetic material, which can enhance genetic diversity, and possibly increasing the resilience of the population to environmental changes.

In contrast, emigration refers to individuals leaving a population to inhabit another area, which would typically lead to a decrease in population size. Mortalities refers to deaths within a population, which can also diminish population numbers. The term populace growth is more general and does not specifically relate to the movement of individuals into a population. Understanding these terms is crucial for studying population ecology and managing biodiversity effectively.