Ecology: Population Distribution and Abundance

Distribution: Geographic area where individuals of a species occur. Abundance: Number of individuals in a given area. Ecologists try to understand what factors determine the distribution and abundance of species. Populations are dynamic—distribution and abundance can change over time and space. ***Understanding the factors that influence these dynamics helps us manage populations for harvest or…

Evolution & Ecology: Natural selection, Gene flow, Speciation, Drift

Humans have a large impact on the environment—pollution, land use change, climate change, etc. We are just beginning to realize that we also cause evolutionary change, and the consequences of this. Ecology and evolution are strongly interconnected. What Is Evolution? Evolution can be viewed as genetic change over time or as a process of descent…

Energy Movement in Ecosystems: Trophic & Energy Pyramid

Organisms can be classified into trophic (feeding) levels depending on how they get their energy. Organisms that get their energy from nonliving sources (sun, organic matter) are called autotrophs (producers) and make up the 1st trophic level. Organisms that get their energy from other living things are called heterotrophs (consumers). Heterotrophs that eat autotrophs make…