Dispersal evolution in currents: spatial sorting promotes philopatry in upstream patches

Contrasting effects of ecological and evolutionary processes on range expansions and shifts

10.22541/au.161217810.03338053/v1 ◽

2021 ◽

Author(s):

Christopher Weiss-Lehman ◽

Allison Shaw

Keyword(s):

Allee Effect ◽

Extinction Risk ◽

Range Shifts ◽

Evolutionary Processes ◽

Ecological Processes ◽

Mate Finding ◽

Factors Influencing ◽

Spatial Sorting ◽

And Shifts ◽

Dispersal Evolution

Research has conclusively demonstrated the potential for dispersal evolution in range expansions and shifts through a process termed spatial sorting. However, the degree of dispersal evolution observed has varied substantially among organisms. Further, it is unknown how the factors influencing dispersal evolution might impact other ecological processes at play. We use an individual-based model to investigate the effects of the underlying genetics of dispersal and mode of reproduction in range expansions and shifts. Spatial sorting behaves similarly to natural selection in that dispersal evolution increases with sexual selection and loci number. Contrary to our predictions, however, increased dispersal does not always improve a population’s ability to track changing conditions. The mate finding Allee effect inherent to sexual reproduction increases extinction risk during range shifts, counteracting the beneficial effect of increased dispersal evolution. Our results demonstrate the importance of considering both ecological and evolutionary processes for understanding range expansions and shifts.

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Spatial sorting as the spatial analogue of natural selection

10.1101/210088 ◽

2017 ◽

Author(s):

Ben L. Phillips ◽

T. Alex Perkins

Keyword(s):

Natural Selection ◽

Habitat Quality ◽

Rapid Evolution ◽

General Mechanism ◽

Dispersal Ability ◽

Spatial Sorting ◽

Temporal Aspects ◽

Varying Environments ◽

High Level ◽

Dispersal Evolution

AbstractIn most systems, dispersal occurs despite clear fitness costs to dispersing individuals. Theory posits that spatial heterogeneity in habitat quality pushes dispersal rates to evolve towards zero, while temporal heterogeneity in habitat quality favours non-zero dispersal rates. One aspect of dispersal evolution that has received a great deal of recent attention is a process known as spatial sorting, which has been referred to as a “shy younger sibling” of natural selection. More precisely, spatial sorting is the process whereby variation in dispersal ability is sorted along density clines and will, in nature, often be a transient phenomenon. Despite this transience, spatial sorting is likely a general mechanism behind non-zero dispersal in spatiotemporally varying environments. While generally transient, spatial sorting is persistent on invasion fronts, where its effect cannot be ignored, causing rapid evolution of traits related to dispersal. Spatial sorting is described in several elegant models, yet these models require a high level of mathematical sophistication and are not accessible to most evolutionary biologists or their students. Here, we frame spatial sorting in terms of the classic haploid and diploid models of natural selection. We show that, on an invasion front, spatial sorting can be conceptualized precisely as selection operating through space rather than (as with natural selection) time, and that genotypes can be viewed as having both spatial and temporal aspects of fitness. The resultant model is strikingly similar to classic models of natural selection. This similarity renders the model easy to understand (and to teach), but also suggests that many established theoretical results around natural selection could apply equally to spatial sorting.

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Exploring mechanisms and origins of reduced dispersal in island Komodo dragons

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2018.1829 ◽

2018 ◽

Vol 285 (1891) ◽

pp. 20181829 ◽

Cited By ~ 4

Author(s):

Tim S. Jessop ◽

Achmad Ariefiandy ◽

Deni Purwandana ◽

Claudio Ciofi ◽

Jeri Imansyah ◽

...

Keyword(s):

Site Fidelity ◽

Niche Partitioning ◽

Direct Selection ◽

Relaxed Selection ◽

Long Distance ◽

Island Species ◽

Spatial Sorting ◽

Multiple Processes ◽

Dispersal Evolution ◽

Long Distance Movement

Loss of dispersal typifies island biotas, but the selective processes driving this phenomenon remain contentious. This is because selection via, both indirect (e.g. relaxed selection or island syndromes) and direct (e.g. natural selection or spatial sorting) processes may be involved, and no study has yet convincingly distinguished between these alternatives. Here, we combined observational and experimental analyses of an island lizard, the Komodo dragon ( Varanus komodoensis , the world's largest lizard), to provide evidence for the actions of multiple processes that could contribute to island dispersal loss. In the Komodo dragon, concordant results from telemetry, simulations, experimental translocations, mark-recapture, and gene flow studies indicated that despite impressive physical and sensory capabilities for long-distance movement, Komodo dragons exhibited near complete dispersal restriction: individuals rarely moved beyond the valleys they were born/captured in. Importantly, lizard site-fidelity was insensitive to common agents of dispersal evolution (i.e. indices of risk for inbreeding, kin and intraspecific competition, and low habitat quality) that consequently reduced survival of resident individuals. We suggest that direct selection restricts movement capacity (e.g. via benefits of spatial philopatry and increased costs of dispersal) alongside use of dispersal-compensating traits (e.g. intraspecific niche partitioning) to constrain dispersal in island species.

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Sex differences in dispersal syndrome are modulated by environment and evolution

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2017.0428 ◽

2018 ◽

Vol 373 (1757) ◽

pp. 20170428 ◽

Cited By ~ 9

Author(s):

Abhishek Mishra ◽

Sudipta Tung ◽

P. M. Shreenidhi ◽

Mohammed Aamir Sadiq ◽

V. R. Shree Sruti ◽

...

Keyword(s):

Sex Differences ◽

Local Adaptation ◽

Dispersal Syndrome ◽

Habitat Matching ◽

Dispersal Syndromes ◽

Spatial Sorting ◽

Laboratory Populations ◽

Dispersal Evolution ◽

Trait Associations

Dispersal syndromes (i.e. suites of phenotypic correlates of dispersal) are potentially important determinants of local adaptation in populations. Species that exhibit sexual dimorphism in their life history or behaviour may exhibit sex-specific differences in their dispersal syndromes. Unfortunately, there is little empirical evidence of sex differences in dispersal syndromes and how they respond to environmental change or dispersal evolution. We investigated these issues using two same-generation studies and a long-term (greater than 70 generations) selection experiment on laboratory populations of Drosophila melanogaster . There was a marked difference between the dispersal syndromes of males and females, the extent of which was modulated by nutrition availability. Moreover, dispersal evolution via spatial sorting reversed the direction of dispersal × sex interaction in one trait (desiccation resistance), while eliminating the sex difference in another trait (body size). Thus, we show that sex differences obtained through same-generation trait-associations (‘ecological dispersal syndromes’) are probably environment-dependent. Moreover, even under constant environments, they are not good predictors of the sex differences in ‘evolutionary dispersal syndrome’ (i.e. trait-associations shaped during dispersal evolution). Our findings have implications for local adaptation in the context of sex-biased dispersal and habitat-matching, as well as for the use of dispersal syndromes as a proxy of dispersal. This article is part of the theme issue ‘Linking local adaptation with the evolution of sex differences’.

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