Diversitat genètica en espècies amenaçades i no amenaçades de lepidosaures

Abstract

Lepidosaurs are the superorder that includes the largest number of threatened reptile species and their extinction risk is sensitive to rise even more in a close future because they are especially vulnerable to environmental changes as a result of anthropic action and climate change. Genetic diversity allows adaptation of species to environmental changes and can determine the evolutionary response of many threatened species. This work has evaluated the relation between genetic diversity and conservation status of lepidosaurs through a review of 105 scientific articles, published since 1998 until 2018 and indexed in the Web of Science, in which genetic diversity studies at loci microsatellites. Recovered data on 97 species of lepidosaurs, basically of the suborders Lacertilia and Serpentes, have ben used to compare variables about allelic diversity and heterozygosis between the categories of conservation status determined by IUCN. The results show that in both suborders the percentage of threatened species studied exceed to the proportion of threatened species described by IUCN. The laboratory effort (number of loci) is greater in the study of threatened species, maybe to compensate the difficulty to capture threatened species during the field work. The species listed on lower risk categories (NT, LC) tend to remain stable in population sizes, but species included in threatened categories (CR, EN, VU) show a reduction of population size. Threatened species of Squamata and Lacertilia have significantly lower levels of allelic diversity and heterozygosity than non-threatened species and, consequently, higher extinction risk. So, the average of number of alleles in non-threatened species of Lacertilia is 8.879±4,454 but 6.44±4.725 in non-threatened species. The average HO was 0.634±0,122 in non-threatened species and 0,488±0,199 in threatened, and the average of HE (0.682±0,139) in non-threatened was significantly higher to the values of threatened ones (0.535±0,237). These differences haven’t been so apparent between the species of Serpentes but in this suborder the number of studied species in some threatened categories was very low