Building the future by doing more together

Generosi - CONtaminant-driven GENEtic ERosion: consequences on the viability of Amphibia populations
Coordinator - Isabel M. Lopes
Execution dates - 2013-06-01 - 2015-05-31 (24 Months)
Funding Entity - FCT
Funding for CESAM - 101000 €
Total Funding - 198664 €
Proponent Institution - Universidade de Aveiro
Participating Institutions
IIIRC, Universidad de Castilla-La Mancha, Spain
IPATIMUP, University of Porto, Portugal
IMAR, University of Coimbra, Portugal

Concerns on potential impacts of chemical contamination on the genetic diversity of natural populations have been increasing. However, in addition to identifying occurrence of contaminant-driven genetic erosion, it is essential to understand long term ecological effects that may follow a loss of genetic diversity. For example, increased susceptibility to different environmental stressors may compromise populations’viability. At present, limited empirical evidence exists supporting the general view that genetic erosion leads to negative evolutionary side effects, and many knowledge gaps are still to be filled. Since populations are regarded as the minimum units for species conservation and environmental protection, then accurate understanding of how contaminants may influence their genetic diversity and the associated consequences on their evolutionary potential is mandatory for better biodiversity conservation. Currently, most published studies addressing this issue fails some permits to establish causality between population genetic effects and contamination; some only monitor neutral markers that may fail to detect directional selective pressures; and only few focus the impacts that loss of genetic diversity can have on the viability of populations. Also, most work has been centred on invertebrates, but, the study of these processes is very important in vertebrate species, as usually they constitute populations with a much smaller number of individuals, and, thus, the effects of contaminants in population genetics may be more exacerbated. Among vertebrates, the study of contaminant-driven genetic erosion in amphibians is pertinent and imperative, as this is a group: (i) with populations declining worldwide: 32% of species are considered threatened and at least 43% are declining (reported by Global Amphibian Assessment project); (ii) for which only few papers addressed the effects of contaminants in populations’ genetic diversity, and most only tackled a perspective of local adaptation, not investigating the occurrence of genetic erosion and its potential consequences in long-term viability of populations; (iii) amphibians are relatively limited in their movements, implying a restricted gene flow and facilitating the occurrence of genetic erosion. According, GENEROSI aims at assessing the occurrence of contaminant-driven genetic erosion in populations of amphibians and its possible consequences in the viability their viability under scenarios of future environmental stressors. Furthermore, it is also intended to understand the role of the amphibian skin symbiotic microbiome in those processes, as, for example it has been shown that this community may be involved in resistance of amphibians to pathogens. To completely achieve these goals, 3 specific objectives were delineated, to evaluate: (i) if metal contamination led to the genetic erosion of exposed populations; (ii) possible mechanisms associated with increased resistance to metals; (iii) if resistance to metals is associated with an increased susceptibility to pathogens (considered one of amphibians’ major threats). To tackle these objectives, two study sites, with similar history of metal contamination, were selected: Mina de São Domingos (SW Portugal) and Valle de Alcudia (SW Spain). At both mines, metal contamination have been occurring for more than a century and, it is expected that amphibian populations inhabiting these sites have had multi-generational exposure to chemical contamination, and, thus the occurrence of genetic erosion due to directional selection could have occurred. Pelophylax perezi will be used as model organism, as it is abundant, widely distributed along the Iberian Peninsula, existing at both study sites. The results obtained at the end of the project will add scientific value at an international level, because this is a pioneering study regarding the: (i) integrated study of genetic erosion in populations of amphibians and its evolutionary consequences; (ii) role of skin microbiome in the resistance acquisition of amphibians to metal contamination, and (iii) linking the effects of contamination in skin microbiome (possible loss of diversity) with the amphibians susceptibility to infectious diseases; (iv) interaction between genetic diversity and fitness is a key element in evolutionary biology and the importance of understanding this process for conservation biology is well acknowledged. Consequently, will allow recommend more accurate protection plans.

Members on this project
Amadeu Soares


Isabel M. Lopes
principal investigator


CESAM Funding: