Genetic considerations

If a species is extirpated from a place where it previously existed, the individuals that make up the reintroduced population should come from wild or captive populations. When procuring individuals for reintroduction, local adaptation, captive adaptation (for ex situ protection), potential for inbreeding and outbreeding suppression, and the taxonomy and ecology of the source population should be considered. It is important to consider genetic diversity as well as genetic diversity. Reintroduced populations are susceptible to drift, selection, and genetic. They become more vulnerable to the effects of the evolutionary process of flow. If the species planned for reintroduction is rare, there is a high probability that the population in the wild is abnormally low, so care should be taken to avoid inbreeding or inbreeding depression. Inbreeding can change the frequency of allele distribution in a population, which can lead to significant changes in genetic diversity. In addition, if the reintroduced population can interbreed with existing populations in the wild, outcrossing suppression can occur, leading to reduced fitness of offspring and increased resistance to local conditions. Adaptation may decrease. To minimize both, professionals select individuals in such a way as to capture as much genetic diversity as possible, matching source conditions to local conditions as closely as possible. should strive to capture as much genetic diversity, measured as heterozygosity, as possible, has been suggested during species reintroductions. Some protocols suggest that isolating approximately 30 individuals from a population yields 95% of the genetic diversity. Maintaining genetic diversity in recipient populations is crucial to avoid the loss of important local adaptations, minimize inbreeding suppression, and maximize the fitness of reintroduced populations.

Ecological similarity

Reintroduced plants and animals may be less suitable if they are poorly adapted to local environmental conditions. Thus, researchers should consider the ecological and environmental similarities between source and recipient when selecting populations for reintroduction. Environmental factors to consider include climate and soil properties (pH, percent clay, silt and sand, percent carbon burned, percent nitrogen burned, Ca, Na, Mg, P, K concentrations). Historically, the procurement of plant material for reintroduction has followed the “local best” rule as the best way to support local adaptations, with individuals for reintroduction being obtained from geographically closest populations. However, general garden experiments have shown that geographic distance is a poor indicator of fitness. In addition, projected climate change-induced climate change has led to the development of new seed-search protocols aimed at finding seeds that are best suited to projected climatic conditions.

Adaptation to captivity

In some reintroduction programs, plants or animals from captive populations are used to form reintroduction populations. When individuals from captive populations are reintroduced into wild populations, there is a risk of adaptation to the conditions of captivity due to differences in genotypic selection between captive and wild conditions. The genetic basis of this adaptation is the selection of rare recessive alleles that are harmful in nature but preferred in captivity. As a result, animals adapted to captive conditions show reduced stress resistance, increased submissiveness, and loss of local adaptation. Plants can also show adaptation to captivity through changes in drought tolerance, nutrient requirements, and seed dormancy requirements. The degree of adaptation is directly related to the strength of selection, genetic diversity, effective population size, and number of generations in captivity. Because traits selected in captivity are highly unfavorable in the wild, such adaptations can lead to reduced fitness after reintroduction.

Genetic trade-offs

In captive reintroductions, the movement of animals from captivity to the wild affects both captive and wild populations. The reintroduction of genetically valuable animals from captivity depletes the captive population while improving the genetic diversity of the reintroduced population. On the contrary, genetically valuable captive-bred animals may be closely related to wild individuals, thus increasing the risk of inbreeding suppression in the event of reintroduction. Increasing genetic diversity is facilitated by removing genetically overrepresented individuals from captive populations and adding animals that are less genetically related to the wild. In practice, however, it is recommended that individuals with low genetic value be reintroduced into the breeding population first to allow for genetic evaluation before moving valuable individuals.