be lost from the population. Outbreeding depression Outbreeding depression is the reduced biological fitness in the offspring of distantly related parents. The decline in fitness due to outbreeding is attributed to a breakup of coadapted gene complexes or favorable epistatic relationships. Unlike inbreeding depression, outbreeding depression emphasizes interactions between loci rather than within them. Inbreeding and outbreeding depression can occur at the same time. Risks of outbreeding depression increase with increased distance between populations. The risk of outbreeding depression during genetic rescue often limits the ability to increase a small or fragmented gene pool's genetic diversity. The spawn of an intermediate of two or more adapted traits can render the adaptation less effective than either of the parental adaptations. Three main mechanisms influence outbreeding depression; genetic drift, population bottlenecking, differentiation of adaptations, and set chromosomal dissimilarities resulting in sterile offspring. If outbreeding is limited and the population is large enough, selective pressure acting on each generation may be able to restore fitness. However, the population is likely to experience a multi-generational decline of overall fitness as selection for traits takes multiple generations. Selection acts on outbred generations using increased diversity to adapt to the environment. This may result in greater fitness among offspring than the original parental type. Conservation units Conservation units are classifications often used in conservation biology, conservation genetics, and molecular ecology in order to separate and group different species or populations based on genetic variance and significance for protection. Two of the most common types of conservation units are: Management Units (MU): Management units are populations that have very low levels of gene flow and can therefore be genetically differentiated from other populations. Evolutionarily significant units (ESU): Evolutionarily significant units are populations that show enough genetic differentiation to warrant their management as distinct units. Conservation units are often identified using both neutral and non-neutral genetic markers, with each having its own advantages. Using neutral markers during unit identification can provide unbiased assumptions of genetic drift and time since reproductive isolation within and among species and populations, while using non-neutral markers can provide more accurate estimations of adaptive evolutionary divergence, which can help determine the potential for a conservation unit to adapt within a certain habitat. Because of conservation units, populations and species that have high or differing levels of genetic variation can be distinguished in order to manage each individually, which can ultimately differ based on a