Genetic diversity

Greater genetic variability allows a population to better adapt to the changes in the environment

Genetic diversity is the diversity of the units of heredity (genes). Genetic diversity, or gene pool, is usually understood in the meaning of genetic diversity within a species or within a population.

Genetic diversity is crucial for nature. Greater genetic variability allows a population to better adapt to the changes in the environment. The richer the gene pool, the likelier it is that a part of the population has characteristics that are fitting in new environmental conditions. Such specimens are more likely to survive and be able to produce offspring. Smaller populations tend to have lower genetic diversity and thus a higher risk of extinction.

Common greenshank. By: Karl Adami
COMMON GREENSHANK. There are 150–200 pairs of the protected category III species nesting in Estonia. That is close to the minimum viable population. Fortunately, the species is not as rare in the rest of the world as it is here. Photo: Karl Adami


This raises the question of whether there is a minimum population size at which a population can survive and not become extinct.

However, the minimum number of individuals required for the survival of a species is not a universal size, but depends on the species in question and a range of different factors (e.g. the breeding strategy of the species). Under farm conditions, these factors can be levelled and the population can be maintained even if the abundance is below the minimum size required to survive in the wild. However, this means external intervention, such as in the form of a breeding programme. For example, within the framework of the European mink captive breeding programme of the Tallinn Zoo, a species that had already become extinct in Estonian nature was restored with the help of specimens brought from other countries.

The protection of genetic diversity is one of the objectives of the Convention on Biological Diversity. However, despite international agreements and many published scientific articles, there is still very little political awareness of the importance of genetic diversity for biodiversity [1].




[1] The importance of genetic diversity