04/9/12 10:04 PM

Genetic factors, an essential component to the extinction of species

Linces descansando. Imagen de archivo. - J.M. Pérez de Ayala

Direct and indirect consequences of human activities are fuelling habitat destruction and driving species to extinction at a rate that is only comparable to that of the past five great extinctions revealed by the fossil record.

A recent global report by the International Union for Conservation of Nature (IUCN) revealed that 17.291 out of the 47.677 species assessed are threatened with extinction, with the ratio of threatened species ranging from 12% for birds to 70% for plants, being 21% for mammals.

In the last few years, genetic factors have been recognized as key components of the set of interacting forces that contribute to the extinction of endangered species. Population declines often result in a decrease in genetic diversity and an increase in inbreeding and in the frequency of deleterious alleles, and these processes may in turn jeopardize species persistence through the associated loss of adaptive potential and reduction in survival and reproduction.

Although the importance of these genetic factors relative to those of demographic and ecological nature was once questioned, an increasing number of experimental and empirical studies indicate that these changes do occur in endangered populations and that they do increase their extinction probabilities.

Given the potential impact of genetic factors on species persistence, the assessment of genetic patterns and the evaluation of genetic risks in endangered populations must become central and fundamental objectives of any conservation program.

Available languages: Spanish
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