The use of molecular genetics has become increasingly important in the fields of wildlife biology, conservation biology, restoration ecology, and ecosystem science. Genetic diversity—the amount of genetic variability within a species—is an important aspect of biological diversity and plays an essential role in the conservation of species and ecosystem diversity. At the species level, conservation of genetic variability is important to the overall health of populations because such variation can represent adaptive responses to different types of environments present within a species' range. This variation may play an important role in surviving novel diseases and adapting to environmental changes associated with anthropogenic (influenced by humans) stressors, such as climate change or habitat loss. Furthermore, because different species coexist in communities, the loss of genetic diversity in one species can affect the structure and composition of the community of species within an ecosystem, which in turn may have a cascading effect on ecosystem health, integrity, and sustainability.