Understanding the biology of species' ranges: when and how does evolution change the rules of ecological engagement?

Abstract

Understanding processes that limit species' ranges has been a core issue in ecology and evolutionary biology for many decades, and has become increasingly important given the need to predict the responses of biological communities to rapid environmental change. However, we still have a poor understanding of evolution at range limits and its capacity to change the ecological ‘rules of engagement’ that define these communities, as well as the time frame over which this occurs. Here we link papers in the current volume to some key concepts involved in the interactions between evolutionary and ecological processes at species' margins. In particular, we separate hypotheses about species’ margins that focus on hard evolutionary limits, which determine how genotypes interact with their environment, from those concerned with soft evolutionary limits, which determine where and when local adaptation can persist in space and time. We show how theoretical models and empirical studies highlight conditions under which gene flow can expand local limits as well as contain them. In doing so, we emphasize the complex interplay between selection, demography and population structure throughout a species' geographical and ecological range that determines its persistence in biological communities. However, despite some impressively detailed studies on range limits, particularly in invertebrates and plants, few generalizations have emerged that can predict evolutionary responses at ecological margins. We outline some directions for future work such as considering the impact of structural genetic variants and metapopulation structure on limits, and the interaction between range limits and the evolution of mating systems and non-random dispersal. This article is part of the theme issue ‘Species’ ranges in the face of changing environments (Part II)’.

Phylogeographical Analysis of the Freshwater Gudgeon Huigobio chenhsienensis (Cypriniformes: Gobionidae) in Southern China

“…Therefore, phylogeographical studies of freshwater fish are significant for understanding the historical reorganization or rearrangements of rivers within and among drainages [ 3 , 4 , 5 , 6 ]. The genetic diversity observed within a species is a key facet of biodiversity that reflects the evolutionary history and adaptability of a species as a whole, or its constituent populations [ 7 , 8 ].…”

Introduction to the theme issue ‘Species' ranges in the face of changing environments’

“…This will allow us to better understand the dynamics of species' ranges in the face of changing environments and, in particular, to establish a solid framework for quantifying the rate at which species' ranges are expected to change, both within and at the edge of their geographical distributions. Bridle & Hoffmann provide a thoughtful summary, alongside a number of most fruitful recommendations for future work on the topic, in the final contribution of the theme issue [ 28 ].…”

“…We believe that providing answers of this type is essential for designing successful policies and management actions aimed at conserving biodiversity or mitigating its loss and maintaining ecological resilience. While the theme issue consists of two parts (part I [ 7 , 9 – 18 ] and part II [ 19 – 28 ]), they should be viewed as a coherent unit. In what follows, we briefly introduce the topics addressed in the theme issue.…”

“…In what follows, we briefly introduce the topics addressed in the theme issue. In the final contribution [ 28 ], Bridle & Hoffmann provide an overview of the conclusions, recommendations and outstanding issues raised.…”

Hidden genetic variation in plasticity provides the potential for rapid adaptation to novel environments

“…Understanding how populations and ecological communities will respond to rapid environmental change remains a fundamental challenge (Bridle and Hoffmann 2022; Parmesan 2006; Shaw and Etterson 2012). Populations respond to new environments either by genotypes adjusting their phenotypes to match changing conditions (adaptive plasticity) (Charmantier et al 2008; Via et al 1995), or by increases in the frequency of beneficial alleles that increase fitness and promote adaptation (termed ‘evolutionary rescue’) (Bell and Gonzalez 2009; Gomulkiewicz and Holt 1995).…”