What living and nonliving components to the desert ecosystem affect populations of Moab’s bighorn sheep? Utah State Science Core Curriculum Topic: Standard 6.4.4 Construct an argument supported by evidence that the stability of populations is affected by changes to an ecosystem. Emphasize how changes to living and nonliving components in an ecosystem affect populations in that ecosystem. Background Populations are groups of organisms that live in the same area. Population size can increase, decrease, or stay the same over time. The stability of populations is affected by many factors, includin