Understanding the impact of pollutants on populations allows to investigate evolutionary processes that may affect population status and their capacity to persist in the future. One of the biggest challenges for an accurate estimation of the impact of chronic pollution on ecosystems is to understand, quantify, and predict its effects not only at individual, but also at the population level of biological organization (Bickham, 2011 Medina et al., 2007 Theodorakis, 2001). Although the short‐term adverse effects of high ionizing radiation doses on wildlife following this accident are not questioned (Alexakhin et al., 2006 Geras’kin et al., 2008 Møller & Mousseau, 2006), there are still many unknowns and controversies on the long‐term ecological consequences of these radioactive releases (Beresford, Horemans et al., 2020 Bréchignac & Paquet, 2013 Morgan & Bair, 2013 Mothersill & Seymour, 2013). This is particularly true in the case of major nuclear accident such as the one occurred at the Chernobyl nuclear power plant (NPP) on April 1986 (Imanaka et al., 2015 Steinhauser et al., 2014). Among the large diversity of pollutants, radioactive contamination caused by human activities, and the associated risks for ecosystems and humans, are the subject of broad societal and scientific concern (Beresford & Copplestone, 2011).
#Purple tree frog species drivers
Pollution, as part of the major drivers of biodiversity loss (namely habitat and climate change, pollution, overexploitation of natural resources, and invasive species), has severely altered many ecosystems (Brondizio et al., 2019). The loss of biodiversity during the past 50 years is unprecedented in human history. These data suggest that Eastern tree frog populations might offset the impact of deleterious mutations because of their large clutch size, but also question the long‐term impact of ionizing radiation on the status of other species living in the Chernobyl exclusion zone. By fitting to our data a model of haplotype network evolution, we suspected that Eastern tree frog populations in the Chernobyl exclusion zone have a high mitochondrial mutation rate and small effective population sizes. Moreover, the study of haplotype network permitted us to decipher the presence of an independent recent evolutionary history of Chernobyl exclusion zone's Eastern tree frogs caused by an elevated mutation rate compared to other European populations. Genetic diversity estimated from nuclear and mitochondrial markers showed an absence of genetic erosion and higher mitochondrial diversity in tree frogs from the Chernobyl exclusion zone compared to other European populations.
Here, we examined genetic markers for 19 populations of Eastern tree frog ( Hyla orientalis) sampled in the Chernobyl region about thirty years after the nuclear power plant accident to investigate microevolutionary processes ongoing in local populations. Notwithstanding the implications of evolutionary processes on the population status, few studies concern the evolution of organisms chronically exposed to ionizing radiation in the Chernobyl exclusion zone. This is the case concerning the radioactive contamination of the environment following the major nuclear accident at the Chernobyl nuclear power plant. Despite the ubiquity of pollutants in the environment, their long‐term ecological consequences are not always clear and still poorly studied.
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