IUCN Red List and the value of integrating genetics

Abstract

Many species on endangered species lists such as the IUCN Red List (RL) are categorized using demographic factors such as numbers of mature individuals. Genetic factors are not currently used in the RL even though their explicit consideration, including effective population size (Ne) and expected heterozygosity-loss (H-loss), could improve the assessment of extinction risk. Here, we consider the estimation of Ne and H-loss in the context of RL species. First, we investigate the reporting of number of mature individuals for RL Endangered species, which is needed to estimate Ne and H-loss. We found 77% of species assessments studied here did not report methods used to estimate the number of mature adults, and that these assessments rarely report other important determinants of Ne (e.g., sex ratio, variance in family size). We therefore applied common rules of thumb to estimate Ne, and found that Ne was likely < 50 for at least 25% of the 170 RL Endangered species studied here. We also estimated mean expected H-loss for these species over the next 100 years, and found it to be 9–29%. These estimates of high H-loss and low Ne suggest that some species listed as Endangered likely warrant listing as Critically Endangered if genetic considerations were included. We recommend that RL and other assessment frameworks (i) report methods used for estimating the number of mature adults, (ii) include standardized information on species traits that influence Ne to facilitate Ne estimation, and (iii) consider using concepts like Ne and heterozygosity-loss in risk assessments.

Extensive standing genetic variation from a small number of founders enables rapid adaptation in Daphnia

“…Maintenance of genetic diversity is an important biodiversity goal 34 , and likely requires multiple sufficiently large populations because of the interdependence of local and regional genetic diversity. Protection and restoration of the evolutionary potential of larger-bodied and less common species that are characterized by low effective population sizes and suffer from loss of evolutionary potential 35,36 should be a high priority, and requires a landscape perspective.…”

Conservation biology of threatened Mediterranean chasmophytes: The case of Asperula naufraga endemic to Zakynthos island (Ionian islands, Greece)

“…Census of the population size facilitate the estimation of Ne , which is in line with the results of the Conservation Status Assessment and should be considered as additional information to assessments as suggested by Garner et al [ 55 ].…”

“…the size of the ideal population with the same rate of genetic drift as in the actual population being considered [ 48 ] was estimated by multiplying the initial abundance ( Nc ) (i.e. census number of mature individuals during the year 2014) by 0.4 and 0.1, representing a common range of Ne / Nc ratios as suggested by Garner et al [ 55 ].…”

Demo-Genetic Approach for the Conservation and Restoration of a Habitat-Forming Octocoral: The Case of Red Coral, Corallium rubrum, in the Réserve Naturelle de Scandola

“…The potential for genetic isolation at local scale, as observed for PLU, is also of management interest. Indeed, isolated populations may be targeted by restoration to increase their effective population size and to buffer potential drift and related negative effects (e.g., expression of deleterious alleles and decrease population fitness; see Frankham, 2005;Garner et al, 2020). Still on the management prioritization, we identified two particular populations, namely, CAVB and ALE, as the main sources of migrants within the network.…”