Comparative genomics approach to evolutionary process connectivity.

Pierre‐Alexandre Gagnaire

doi:10.1111/eva.12978

Abstract

The influence of species life history traits and historical demography on contemporary connectivity is still poorly understood. However, these factors partly determine the evolutionary responses of species to anthropogenic landscape alterations. Genetic connectivity and its evolutionary outcomes depend on a variety of spatially dependent evolutionary processes, such as population structure, local adaptation, genetic admixture, and speciation. Over the last years, population genomic studies have been interrogating these processes with increasing resolution, revealing a large diversity of species responses to spatially structured landscapes. In parallel, multispecies meta‐analyses usually based on low‐genome coverage data have provided fundamental insights into the ecological determinants of genetic connectivity, such as the influence of key life history traits on population structure. However, comparative studies still lack a thorough integration of macro‐ and micro‐evolutionary scales to fully realize their potential. Here, I present how a comparative genomics framework may provide a deeper understanding of evolutionary process connectivity. This framework relies on coupling the inference of long‐term demographic and selective history with an assessment of the contemporary consequences of genetic connectivity. Standardizing this approach across several species occupying the same landscape should help understand how spatial environmental heterogeneity has shaped the diversity of historical and contemporary connectivity patterns in different taxa with contrasted life history traits. I will argue that a reasonable amount of genome sequence data can be sufficient to resolve and connect complex macro‐ and micro‐evolutionary histories. Ultimately, implementing this framework in varied taxonomic groups is expected to improve scientific guidelines for conservation and management policies.

Highlights

Anthropogenic landscape alterations affect all strata of marine and terrestrial ecosystems (Boivin et al, 2016; Halpern et al, 2008)
The results showed that most of the divergent glacial lineages have remained partially reproductively isolated despite hybridization (April, Hanner, Dion-Côté, & Bernatchez, 2013)
The purpose of this review is to encourage continued efforts to link comparative phylogeography and population genomics to address conservation issues related to connectivity

Summary

Introduction

Anthropogenic landscape alterations affect all strata of marine and terrestrial ecosystems (Boivin et al, 2016; Halpern et al, 2008). Habitat fragmentation or the breaking of physical links connecting habitats patches can affect landscape connectivity, which refers to measurable physical connectivity between habitat patches in a landscape. In addition to this, the way in which a given landscape is perceived from the “species-eye” view can lead to a more complex canvas of habitat connectivity (Lindenmayer & Fischer, 2007). Species-specific constrained ability to disperse through the landscape may generate additional reductions in connectedness between patches of suitable habitat, due for instance to behavioral components. The physical spatial structure of a landscape can impose different connectivity constraints, depending on species

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