Biotic interactions matter in phylogeography research: Integrative analysis of demographic, genetic and distribution data to account for them

Abstract

It is well established that biotic-interspecific interactions, such as competition, mutualism, parasitism or predation, modulate species dynamics in demographic and evolutionary terms. It is also acknowledged that biotic interactions can even have major effects on local population dynamics and scale-up to determine wider species' ranges (Wisz et al., 2013). Notwithstanding, the study of biotic interactions has been mostly ignored in biogeography and phylogeography research, for which it has been long assumed that abiotic factors (e.g. climate) mostly drive the ecological and evolutionary processes that underlie species' distribution. Consequently, our knowledge is scarce about the role of biotic interactions in determining spatial patterns of genetic diversity and structure. In a From the Cover article in this issue of Molecular Ecology, Ortego & Knowles (2020) address the study of positive and negative plant-plant interactions and test whether their demographic consequences translate into broadscale patterns of genomic variation in two oak species from the iconic California Floristic Province. The integrative approach undertaken in this study reveals that some models that incorporate competition or facilitation better explain genomic patterns than null models in which species respond only to variations in environmental suitability. These findings highlight the relevance of biologically informed model-based approaches for inferring the evolutionary consequences of species' range dynamics, which is of particular importance in today's global change context.