Bridging population genetics and the metacommunity perspective to unravel the biogeographic processes shaping genetic differentiation of Myriophyllum alterniflorum DC.

Jorge García-Girón,Margarita Fernández-Aláez,Eloy Bécares,Pedro García,Camino Fernández-Aláez

doi:10.1038/s41598-019-54725-7

Jorge García-Girón, Margarita Fernández-Aláez + Show 3 more

Open Access

https://doi.org/10.1038/s41598-019-54725-7

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Journal: Scientific Reports	Publication Date: Dec 1, 2019
Citations: 6	License type: open-access

Affiliation: University of Leon

Abstract

The degree to which dispersal limitation interacts with environmental filtering has intrigued metacommunity ecologists and molecular biogeographers since the beginning of both research disciplines. Since genetic methods are superior to coarse proxies of dispersal, understanding how environmental and geographic factors influence population genetic structure is becoming a fundamental issue for population genetics and also one of the most challenging avenues for metacommunity ecology. In this study of the aquatic macrophyte Myriophyllum alterniflorum DC., we explored the spatial genetic variation of eleven populations from the Iberian Plateau by means of microsatellite loci, and examined if the results obtained through genetic methods match modern perspectives of metacommunity theory. To do this, we applied a combination of robust statistical routines including network analysis, causal modelling and multiple matrix regression with randomization. Our findings revealed that macrophyte populations clustered into genetic groups that mirrored their geographic distributions. Importantly, we found a significant correlation between genetic variation and geographic distance at the regional scale. By using effective (genetic) dispersal estimates, our results are broadly in line with recent findings from metacommunity theory and re-emphasize the need to go beyond the historically predominant paradigm of understanding environmental heterogeneity as the main force driving macrophyte diversity patterns.

Highlights

The degree to which dispersal limitation interacts with environmental filtering has intrigued metacommunity ecologists and molecular biogeographers since the beginning of both research disciplines
Since gene flow estimations are certainly superior to coarse proxies of dispersal, understanding how environmental and geographic factors influence the genetic structure of biodiversity is becoming one of the most fundamental issues for population genetics[14] and one of the most challenging avenues for metacommunity ecology[10]
The theory of isolation by distance describes the local accumulation of genetic differences when dispersal among populations is limited by geographic factors, and gene flow is inversely proportional to the distance between populations[4,15]

Summary

Introduction

The degree to which dispersal limitation interacts with environmental filtering has intrigued metacommunity ecologists and molecular biogeographers since the beginning of both research disciplines. Much of modern freshwater ecology is founded on the principle of environmental determinism and its findings are still subject www.nature.com/scientificreports to revision In this vein, the recent macroecological study of Alahuhta et al.[9] (using partial redundancy analysis and the standard variation partitioning approach) showed that environmental filtering overrode the effects of potential connectivity in explaining local communities across the world. A classic example of this scenario in the freshwater realm comes from plants growing on and near the reaches of lakes and rivers, where local adaptations to different sediment and soil types have occurred[4] Both patterns of IBD and IBE are usually present simultaneously in nature[4] and represent one of the most important approaches with which to assess the relative importance of geographic distance and environmental heterogeneity in shaping patterns of dispersal and genetic variation[14,16,17]

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