Age structure is the number of individuals of each age within the population. Biological diversity is the variety of life from the genetic make-up of species to populations, habitats, and ecosystems.
Conservation is the management of a natural resource so that it can be sustained over the long-term.
Conservation biology is a multidisciplinary science that has developed to deal with the crisis of declining biological diversity. Critical habitat , a term used in the Endangered Species Act, includes areas in which are found the physical and biological features essential to the conservation of a species. Cross-fostering is a captive propagation technique in which the young or eggs of one species are raised by another species. Endangered Species are defined under the Endangered Species Act as those species in danger of becoming extinct throughout all or a significant portion of their range. Evolutionary Units are segments of biological diversity that contain the potential for a unique evolutionary future.