Are molecular markers useful predictors of adaptive potential?

Abstract

Estimates of molecular genetic variation are often used as a cheap and simple surrogate for a population's adaptive potential, yet empirical evidence suggests they are unlikely to be a valid proxy. However, this evidence is based on molecular genetic variation poorly predicting estimates of adaptive potential rather than how well it predicts true values. As a consequence, the relationship has been systematically underestimated and the precision with which it could be measured severely overstated. By collating a large database, and using suitable statistical methods, we obtain a 95% upper bound of 0.26 for the proportion of variance in quantitative genetic variation explained by molecular diversity. The relationship is probably too weak to be useful, but this conclusion must be taken as provisional: less noisy estimates of quantitative genetic variation are required. In contrast, and perhaps surprisingly, current sampling strategies appear sufficient for characterising a population's molecular genetic variation at comparable markers.

Constraints to and conservation implications for climate change adaptation in plants

“…Here, we consider two genomic techniques that hold real promise in advancing our understanding of plant adaptation and highlight how we can use this knowledge to more clearly direct conservation actions. It is important to note, however, that the use of molecular markers as a measure of a population's adaptive potential can be unreliable (Mittell et al 2015) and so the identification of levels of genetic variation among genetic markers should not be taken as direct evidence for a population's future adaptive potential.…”

Dispersal responses override density effects on genetic diversity during post-disturbance succession

“…R. Soc. B 283: 20152934 [51]) that would increase extinction risk under changing disturbance regimes. For example, what spatial and temporal scales of fire regimes would cause sufficient declines in genetic diversity to inhibit adaptive potential?…”

Ecological and association genetics in two Mediterranean pine species

“…Molecular markers can be used as a starting point in conservation policies, as they provide information about historical evolutionary divergence and demographic processes (Fraser and Bernatchez 2001). But molecular genetic markers alone do not provide a reliable tool for conservation geneticists wanting to measure a population's adaptive potential, as patterns identified in quantitative adaptive traits normally differ from those observed using neutral or weakly selected loci (Fraser and Bernatchez 2001;Frankham 2010;Mittell et al 2015). A combined approach including molecular, quantitative and ecological data, although rarely employed, is fundamental and would allow the integration of evolutionary processes in conservation planning (Rader et al 2005;Ouborg et al 2006;Sgrò et al 2011).…”