1
|
Hitchcock TJ, Gardner A. Sex-biased demography modulates male harm across the genome. Proc Biol Sci 2021; 288:20212237. [PMID: 34933602 PMCID: PMC8692969 DOI: 10.1098/rspb.2021.2237] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 11/26/2021] [Indexed: 11/22/2022] Open
Abstract
Recent years have seen an explosion of theoretical and empirical interest in the role that kin selection plays in shaping patterns of sexual conflict, with a particular focus on male harming traits. However, this work has focused solely on autosomal genes, and as such it remains unclear how demography modulates the evolution of male harm loci occurring in other portions of the genome, such as sex chromosomes and cytoplasmic elements. To investigate this, we extend existing models of sexual conflict for application to these different modes of inheritance. We first analyse the general case, revealing how sex-specific relatedness, reproductive value and the intensity of local competition combine to determine the potential for male harm. We then analyse a series of demographically explicit models, to assess how dispersal, overlapping generations, reproductive skew and the mechanism of population regulation affect sexual conflict across the genome, and drive conflict between nuclear and cytoplasmic genes. We then explore the effects of sex biases in these demographic parameters, showing how they may drive further conflicts between autosomes and sex chromosomes. Finally, we outline how different crossing schemes may be used to identify signatures of these intragenomic conflicts.
Collapse
Affiliation(s)
| | - Andy Gardner
- School of Biology, University of St Andrews, St Andrews KY16 9TH, UK
| |
Collapse
|
2
|
R Rodrigues L, Torralba Sáez M, Alpedrinha J, Lefèvre S, Brengues M, Magalhães S, Duncan AB. Consequences of population structure for sex allocation and sexual conflict. J Evol Biol 2021; 34:525-536. [PMID: 33314358 DOI: 10.1111/jeb.13755] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 11/07/2020] [Accepted: 11/30/2020] [Indexed: 11/29/2022]
Abstract
Both sex allocation and sexual conflict can be modulated by spatial structure. However, how the interplay between the type of dispersal and the scale of competition simultaneously affects these traits in sub-divided populations is rarely considered. We investigated sex allocation and sexual conflict evolution in meta-populations of the spider mite Tetranychus urticae evolving under budding (pairing females from the same patch) or random (pairing females from different patches) dispersal and either local (fixed sampling from each subpopulation) or global (sampling as a function of subpopulation productivity) competition. Females evolving under budding dispersal produced less female-biased offspring sex ratios than those from the random dispersal selection regimes, contradicting theoretical predictions. In contrast, the scale of competition did not strongly affect sex allocation. Offspring sex ratio and female fecundity were unaffected by the number of mates, but female fecundity was highest when their mates evolved under budding dispersal, suggesting these males inflict less harm than those evolving under random dispersal. This work highlights that population structure can impact the evolution of sex allocation and sexual conflict. Moreover, selection on either trait may reciprocally affect the evolution of the other, for example via effects on fecundity.
Collapse
Affiliation(s)
- Leonor R Rodrigues
- cE3c, Centre for Ecology, Evolution, and Environmental Changes, Faculty of Sciences, University of Lisbon, Lisboa, Portugal
| | - Mario Torralba Sáez
- Institut des Sciences de l'Évolution, Université de Montpellier, CNRS, IRD, EPHE, Montpellier, France
| | - João Alpedrinha
- cE3c, Centre for Ecology, Evolution, and Environmental Changes, Faculty of Sciences, University of Lisbon, Lisboa, Portugal
| | - Sophie Lefèvre
- Institut des Sciences de l'Évolution, Université de Montpellier, CNRS, IRD, EPHE, Montpellier, France
| | | | - Sara Magalhães
- cE3c, Centre for Ecology, Evolution, and Environmental Changes, Faculty of Sciences, University of Lisbon, Lisboa, Portugal
| | - Alison B Duncan
- Institut des Sciences de l'Évolution, Université de Montpellier, CNRS, IRD, EPHE, Montpellier, France
| |
Collapse
|
3
|
Lymbery SJ, Wyber B, Tomkins JL, Simmons LW. No evidence for divergence in male harmfulness or female resistance in response to changes in the opportunity for dispersal. J Evol Biol 2020; 33:966-978. [PMID: 32279381 DOI: 10.1111/jeb.13628] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 04/01/2020] [Indexed: 12/24/2022]
Abstract
The outcome of sexual conflict can depend on the social environment, as males respond to changes in the inclusive fitness payoffs of harmfulness and harm females less when they compete with familiar relatives. Theoretical models also predict that if limited male dispersal predictably enhances local relatedness while maintaining global competition, kin selection can produce evolutionary divergences in male harmfulness among populations. Experimental tests of these predictions, however, are rare. We assessed rates of dispersal in female and male seed beetles Callosobruchus maculatus, a model species for studies of sexual conflict, in an experimental setting. Females dispersed significantly more often than males, but dispersing males travelled just as far as dispersing females. Next, we used experimental evolution to test whether limiting dispersal allowed the action of kin selection to affect divergence in male harmfulness and female resistance. Populations of C. maculatus were evolved for 20 and 25 generations under one of three dispersal regimens: completely free dispersal, limited dispersal and no dispersal. There was no divergence among treatments in female reproductive tract scarring, ejaculate size, mating behaviour, fitness of experimental females mated to stock males or fitness of stock females mated to experimental males. We suggest that this is likely due to insufficient strength of kin selection rather than a lack of genetic variation or time for selection. Limited dispersal alone is therefore not sufficient for kin selection to reduce male harmfulness in this species, consistent with general predictions that limited dispersal will only allow kin selection if local relatedness is independent of the intensity of competition among kin.
Collapse
Affiliation(s)
- Samuel J Lymbery
- Centre for Evolutionary Biology, School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Blake Wyber
- Centre for Evolutionary Biology, School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Joseph L Tomkins
- Centre for Evolutionary Biology, School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Leigh W Simmons
- Centre for Evolutionary Biology, School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
| |
Collapse
|
4
|
Lymbery SJ, Simmons LW. Males harm females less when competing with familiar relatives. Proc Biol Sci 2017; 284:20171984. [PMID: 29142115 PMCID: PMC5719177 DOI: 10.1098/rspb.2017.1984] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 10/16/2017] [Indexed: 11/12/2022] Open
Abstract
Sexual conflict occurs when reproductive partners have different fitness optima, and can lead to the evolution of traits in one sex that inflict fitness costs on the opposite sex. Recently, it has been proposed that antagonism by males towards females should be reduced when they compete with relatives, because reducing the future productivity of a female would result in an indirect fitness cost for a harmful male. We tested this prediction in the seed beetle Callosobruchus maculatus, the males of which harm females with genital spines and pre-copulatory harassment. We compared lifespan, lifetime egg production and lifetime offspring production among females housed with groups of males that varied in their familiarity and relatedness. Females produced significantly more eggs and offspring when grouped with males who were both related and familiar to each other. There was no effect of male relatedness or familiarity on female lifespan. Our results suggest that males plastically adjust their harmfulness towards females in response to changes in inclusive fitness payoffs, and that in this species both genetic relatedness and social familiarity mediate this effect.
Collapse
Affiliation(s)
- Samuel J Lymbery
- Centre for Evolutionary Biology, School of Biological Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| | - Leigh W Simmons
- Centre for Evolutionary Biology, School of Biological Sciences, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia
| |
Collapse
|
5
|
Schrempf A, von Wyschetzki K, Klein A, Schrader L, Oettler J, Heinze J. Mating with an allopatric male triggers immune response and decreases longevity of ant queens. Mol Ecol 2015; 24:3618-27. [DOI: 10.1111/mec.13267] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 05/24/2015] [Accepted: 06/03/2015] [Indexed: 12/14/2022]
Affiliation(s)
- A. Schrempf
- Zoology/Evolutionary Biology; Universität Regensburg; Universitätsstraße 31 D-93040 Regensburg Germany
| | - K. von Wyschetzki
- Zoology/Evolutionary Biology; Universität Regensburg; Universitätsstraße 31 D-93040 Regensburg Germany
| | - A. Klein
- Zoology/Evolutionary Biology; Universität Regensburg; Universitätsstraße 31 D-93040 Regensburg Germany
| | - L. Schrader
- Zoology/Evolutionary Biology; Universität Regensburg; Universitätsstraße 31 D-93040 Regensburg Germany
| | - J. Oettler
- Zoology/Evolutionary Biology; Universität Regensburg; Universitätsstraße 31 D-93040 Regensburg Germany
| | - J. Heinze
- Zoology/Evolutionary Biology; Universität Regensburg; Universitätsstraße 31 D-93040 Regensburg Germany
| |
Collapse
|
6
|
Abstract
Males and females do not always share the same evolutionary interests. This is particularly true in the case of multiple mating, where male-male competition can often lead to adaptations that are harmful to the female, and females can evolve counter adaptations to reduce the benefits males gain from such traits. Although social evolution has made substantial progress from kin selection theory, most studies of sexual conflict have ignored the effects of genetic relatedness. Here, I use a model of male harm and female resistance to investigate how kin selection affects the evolution of sexual conflict. Building on models of social evolution, I show that relatedness inhibits sexual conflict, in terms of male harm, whereas it has no effect on the evolution female resistance. This study examines a previously neglected mechanism that can potentially help to resolve sexual conflict over mating and highlights the potential importance of considering relatedness in empirical studies of sexual conflict.
Collapse
Affiliation(s)
- D J Rankin
- Department of Biochemistry, University of Zürich, Zürich, Switzerland.
| |
Collapse
|
7
|
Affiliation(s)
- Tracey Chapman
- School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
| |
Collapse
|