Human population size isinfluenced by a combination offactors, including naturalforces like disease, famine,and natural disasters. However, human population Read more Ecosystems +2 What are two ways an organisms joina population and two ways organisms leave a population?Asked by Wiki UserOrganismscan join a population through birth (natality) or demo slot anti lagimmigration. Conversely, they can leave a population through death (mortality) or emigration.