1
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Salamanca-Carreño A, Parés-Casanova PM, Vélez-Terranova M, Martínez-Correal G, Rangel-Pachón DE. Size Gynomimicry in the Sanmartinero Creole Bovine of the Colombian Orinoquia. Vet Sci 2024; 11:304. [PMID: 39057988 PMCID: PMC11281368 DOI: 10.3390/vetsci11070304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 05/31/2024] [Accepted: 06/24/2024] [Indexed: 07/28/2024] Open
Abstract
Variations in the size of animals of the same species but of different sex are called sexual size dimorphism. The aim of this study was to compare the biometrics between males and females of the Sanmartinero creole bovine, of Colombia, to establish if sexual dimorphism appears in the breed. A total of 94 animals (16 uncastrated males and 78 females, average age of 4.3 ± 1.4 and 4.2 ± 2.3 years, respectively) from three different farms were measured. A total of 21 linear variables were obtained using standard morphometric methods and live weight. A one-way NPMANOVA was used to evaluate between sexes, ages, and farms, a Principal Component Analysis was used to detect the most discriminating variables, and a multivariate regression used age as an independent value. Statistically significant differences were reflected between sexes (p = 0.033) and not by age and farms. The variables that differentiated the most between males and females were those related to size (thoracic circumference, body length, dorso-sternal diameter, height at the withers, height at the rump, and horn length), variables that were biased toward males, although only the height at the withers and the rump were the ones that presented statistically significant differences.
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Affiliation(s)
- Arcesio Salamanca-Carreño
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Cooperativa de Colombia, Villavicencio 500001, Colombia
| | | | - Mauricio Vélez-Terranova
- Facultad de Ciencias Agropecuarias, Universidad Nacional de Colombia sede Palmira, Palmira 763531, Colombia
| | - Germán Martínez-Correal
- Asociación de Criadores de Bovinos de Razas Criollas y Colombianas de los Llanos Orientales, Villavicencio 500001, Colombia
| | - David Eduardo Rangel-Pachón
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Cooperativa de Colombia, Villavicencio 500001, Colombia
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2
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Anker-Nilssen T, Kadin M, Hilde CH. Stay or go? Changing breeding conditions affect sexual difference in colony attendance strategies of Atlantic puffins Fratercula arctica. Ecol Evol 2024; 14:e11681. [PMID: 38988346 PMCID: PMC11236458 DOI: 10.1002/ece3.11681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 06/06/2024] [Accepted: 06/19/2024] [Indexed: 07/12/2024] Open
Abstract
Male and female birds have different roles in reproduction and, thereby in their reproductive investment, which in turn may increase negative effects of poorer breeding conditions caused by e.g., climate change or ecosystem regime shifts. By using a 33-year time series of resightings of Atlantic puffins Fratercula arctica individually colour-ringed as breeders in previous years, we showed that the difference in colony attendance of male and female birds depended on the environmental conditions for raising young, proxied by the average duration of the chick period and size of the herring Clupea harengus fed to the chicks in the colony each year. The longer the chick period, the more was the sex ratio of adults sitting visibly in the colony biased in favour of males. An increase in herring size, indicating better feeding conditions for raising chicks, led to more observations of both sexes. Additionally, we found that birds were observed less with age and females more so than males. We discuss the results in relation to general life-history theory on sexual differences in trade-offs between individual investment in breeding and own survival. Our results suggest that females are increasingly more willing than males to invest in provisioning for the chick the more and longer the chick needs such care.
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Affiliation(s)
| | - Martina Kadin
- Swedish Museum of Natural History Stockholm Sweden
- School of Aquatic & Fishery Sciences University of Washington Seattle Washington USA
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3
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Holmes KG, Krützen M, Ridley AR, Allen SJ, Connor RC, Gerber L, Flaherty Stamm C, King SL. Juvenile social play predicts adult reproductive success in male bottlenose dolphins. Proc Natl Acad Sci U S A 2024; 121:e2305948121. [PMID: 38857400 PMCID: PMC11194510 DOI: 10.1073/pnas.2305948121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 03/14/2024] [Indexed: 06/12/2024] Open
Abstract
For over a century, the evolution of animal play has sparked scientific curiosity. The prevalence of social play in juvenile mammals suggests that play is a beneficial behavior, potentially contributing to individual fitness. Yet evidence from wild animals supporting the long-hypothesized link between juvenile social play, adult behavior, and fitness remains limited. In Western Australia, adult male bottlenose dolphins (Tursiops aduncus) form multilevel alliances that are crucial for their reproductive success. A key adult mating behavior involves allied males using joint action to herd individual females. Juveniles of both sexes invest significant time in play that resembles adult herding-taking turns in mature male (actor) and female (receiver) roles. Using a 32-y dataset of individual-level association patterns, paternity success, and behavioral observations, we show that juvenile males with stronger social bonds are significantly more likely to engage in joint action when play-herding in actor roles. Juvenile males also monopolized the actor role and produced an adult male herding vocalization ("pops") when playing with females. Notably, males who spent more time playing in the actor role as juveniles achieved more paternities as adults. These findings not only reveal that play behavior provides male dolphins with mating skill practice years before they sexually mature but also demonstrate in a wild animal population that juvenile social play predicts adult reproductive success.
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Affiliation(s)
- Kathryn G. Holmes
- Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, Crawley, WA6009, Australia
| | - Michael Krützen
- Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, Crawley, WA6009, Australia
- Evolutionary Genetics Group, Department of Evolutionary Anthropology, University of Zurich, Zurich8057, Switzerland
| | - Amanda R. Ridley
- Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, Crawley, WA6009, Australia
| | - Simon J. Allen
- Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, Crawley, WA6009, Australia
- Evolutionary Genetics Group, Department of Evolutionary Anthropology, University of Zurich, Zurich8057, Switzerland
- School of Biological Sciences, University of Bristol, BristolBS8 1TQ, United Kingdom
| | - Richard C. Connor
- Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, Crawley, WA6009, Australia
- Biology Department, University of Massachusetts Dartmouth, North Dartmouth, MA02747
- Department of Biological Sciences and Institute of Environment, Florida International University, North Miami, FL33181
| | - Livia Gerber
- Evolutionary Genetics Group, Department of Evolutionary Anthropology, University of Zurich, Zurich8057, Switzerland
- Australian National Wildlife Collection, National Research Collections Australia, Commonwealth Scientific and Industrial Research Organisation, Canberra, ACT2601, Australia
| | | | - Stephanie L. King
- Centre for Evolutionary Biology, School of Biological Sciences, University of Western Australia, Crawley, WA6009, Australia
- School of Biological Sciences, University of Bristol, BristolBS8 1TQ, United Kingdom
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4
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Pärssinen V, Simmons LW, Kvarnemo C. Mating competition among females: testing the distinction between natural and sexual selection in an insect. ROYAL SOCIETY OPEN SCIENCE 2024; 11:240191. [PMID: 38586425 PMCID: PMC10999239 DOI: 10.1098/rsos.240191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 02/10/2024] [Indexed: 04/09/2024]
Abstract
In species where females compete for mates, the male often provides the female with resources in addition to gametes. A recently suggested definition of sexual selection proposed that if females only benefit from additional resources that come with each mating and not additional gametes, female intrasexual competition for mating opportunities would result in natural selection rather than sexual selection. The nuptial gift-giving bushcricket Kawanaphila nartee has dynamic sex roles and has been a textbook example of sexual selection acting on females via mating competition. We investigated whether females of this species gain fitness benefits from nuptial gifts, additional ejaculates or both by controlling the number of matings and whether the female was allowed to consume the nutritious gift (spermatophylax) at mating. We found that egg production per day of life increased with the number of additional matings, both with and without spermatophylax consumption, but consuming the spermatophylax had an additional positive effect on the number of eggs. These effects were particularly strong in females with shorter lifespans. We discuss how the recently suggested definition of sexual selection applies to nuptial-feeding insects and conclude that both natural and sexual selections influence mating competition in K. nartee females.
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Affiliation(s)
- Varpu Pärssinen
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg40530, Sweden
| | - Leigh W. Simmons
- Centre for Evolutionary Biology, School of Biological Sciences (M092), The University of Western Australia, Crawley6009, Australia
| | - Charlotta Kvarnemo
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg40530, Sweden
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5
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Sharda S, Hollis B, Kawecki TJ. Sex ratio affects sexual selection against mutant alleles in a locus-specific way. Behav Ecol 2024; 35:arad110. [PMID: 38162691 PMCID: PMC10756055 DOI: 10.1093/beheco/arad110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/11/2023] [Accepted: 12/11/2023] [Indexed: 01/03/2024] Open
Abstract
Higher male:female operational sex ratio (OSR) is often assumed to lead to stronger sexual selection on males. Yet, this premise has been directly tested by very few studies, with mixed outcomes. We investigated how OSR affects the strength of sexual selection against two deleterious alleles, a natural ebony mutant and a transgenic GFP insertion, in Drosophila melanogaster. To this end, we estimated the relative paternity share of homozygous mutant males competing against wild-type males under different OSRs (1:2, 1:1, 2:1). We also manipulated the mating pool density (18, 36, or 54 individuals) and assessed paternity over three consecutive days, during which the nature of sexual interaction changed. The strength of sexual selection against the ebony mutant increased with OSR, became weaker after the first day, and was little affected by density. In contrast, sexual selection against the GFP transgene was markedly affected by density: at the highest density, it increased with OSR, but at lower densities, it was strongest at 1:1 OSR, remaining strong throughout the experiment. Thus, while OSR can strongly affect the strength of sexual selection against "bad genes," it does not necessarily increase monotonically with male:female OSR. Furthermore, the pattern of relationship between OSR and the strength of sexual selection can be locus-specific, likely reflecting the specific phenotypic effects of the mutation.
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Affiliation(s)
- Sakshi Sharda
- Department of Ecology and Evolution, University of Lausanne, Biophore, CH-1015 Lausanne, Switzerland and
| | - Brian Hollis
- Department of Biological Sciences, University of South Carolina, 715 Sumter St., Columbia SC 29208, USA
| | - Tadeusz J Kawecki
- Department of Ecology and Evolution, University of Lausanne, Biophore, CH-1015 Lausanne, Switzerland and
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6
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Benvenuto C, Lorenzi MC. Social regulation of reproduction: control or signal? Trends Ecol Evol 2023; 38:1028-1040. [PMID: 37385846 DOI: 10.1016/j.tree.2023.05.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 05/12/2023] [Accepted: 05/12/2023] [Indexed: 07/01/2023]
Abstract
Traditionally, dominant breeders have been considered to be able to control the reproduction of other individuals in multimember groups that have high variance in reproductive success/reproductive skew (e.g., forced sterility/coercion of conspecifics in eusocial animals; sex-change suppression in sequential hermaphrodites). These actions are typically presented as active impositions by reproductively dominant individuals. However, how can individuals regulate the reproductive physiology of others? Alternatively, all contestants make reproductive decisions, and less successful individuals self-downregulate reproduction in the presence of dominant breeders. Shifting perspective from a top-down manipulation to a broader view, which includes all contenders, and using a multitaxon approach, we propose a unifying framework for the resolution of reproductive skew conflicts based on signalling rather than control, along a continuum of levels of strategic regulation of reproduction.
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Affiliation(s)
- Chiara Benvenuto
- School of Science, Engineering, and Environment, University of Salford, Salford, UK.
| | - Maria Cristina Lorenzi
- Laboratoire d'Ethologie Expérimentale et Comparée (LEEC), Université Sorbonne Paris Nord, Villetaneuse, France
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7
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Man C, Gilissen E, Michaud M. Sexual dimorphism in the cranium and endocast of the eastern lowland gorillas (Gorilla beringei graueri). J Hum Evol 2023; 184:103439. [PMID: 37804559 DOI: 10.1016/j.jhevol.2023.103439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 09/04/2023] [Accepted: 09/04/2023] [Indexed: 10/09/2023]
Abstract
Sexual dimorphism of the nervous system has been reported for a wide range of vertebrates. However, understanding of sexual dimorphism in primate cranial structures and soft tissues, and more particularly the brain, remains limited. In this study, we aimed to investigate the external and internal (i.e., endocast) cranial differences between male and female eastern lowland gorillas (Gorilla beringei graueri). We examined the differences in the size, shape, and disparity with the aim to compare how sexual dimorphism can impact these two structures distinctively, with a particular focus on the endocranium. To do so, we reconstructed gorilla external crania and endocasts from CT scans and used 3D geometric morphometric techniques combined with multivariate analyses to assess the cranial and endocranial differences between the sexes. Our results highlighted sexual dimorphism for the external cranium and endocast with regard to both size and shape. In particular, males display an elongated face accompanied by a pronounced sagittal crest and an elongated endocast along the rostroposterior axis, in contrast to females who are identified by a more rounded brain case and endocast. Males also show a significantly larger external cranium and endocast size than females. In addition, we described important differences for the posterior cranial fossae (i.e., the position of the cerebellum within the brain case) and olfactory bulb between the two sexes. Particularly, our results highlighted that, relatively to males, females have larger posterior cranial fossae, whereas males have been characterized by a larger and rostrally oriented olfactory bulb.
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Affiliation(s)
- Caitlin Man
- Laboratory of Ecology, Evolution and Biodiversity Conservation, Katholieke Universiteit Leuven, Charles Deberiotstraat 32 Bus 2439, 3000 Leuven, Belgium; Department of African Zoology, Royal Museum for Central Africa, Leuvensesteenweg 13, 3080 Tervuren, Belgium.
| | - Emmanuel Gilissen
- Department of African Zoology, Royal Museum for Central Africa, Leuvensesteenweg 13, 3080 Tervuren, Belgium; Laboratory of Histology and Neuropathology, Université Libre de Bruxelles, CP620 - Route de Lennik 808, 1070 Brussels, Belgium
| | - Margot Michaud
- Department of African Zoology, Royal Museum for Central Africa, Leuvensesteenweg 13, 3080 Tervuren, Belgium
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8
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McDonald GC. The impact of small groups on pre- and postcopulatory sexual selection in polyandrous populations. Ecol Evol 2023; 13:e10057. [PMID: 37153025 PMCID: PMC10154804 DOI: 10.1002/ece3.10057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 04/08/2023] [Accepted: 04/19/2023] [Indexed: 05/09/2023] Open
Abstract
Sexual selection is a key evolutionary force but varies widely between populations. Two key factors that influence sexual selection are the extent to which females copulate with multiple males (polyandry) and variation in the social environment. Increasing research demonstrates populations are structured by complex socio-sexual networks, and the structure of these networks can influence sexual selection by shaping the relationship between male precopulatory mating success and the intensity of postcopulatory competition. However, comparatively less attention has been dedicated to the influence of group structure on sexual selection and how differences in the size of groups may impact on the relative force of pre- and postcopulatory sexual selection in polyandrous populations. The presence of groups (i.e., group structure) and the size of groups varies widely in nature and forms an implicit part of much experimental sexual selection research under laboratory conditions. Here I use simulations of mating competition within populations that vary in the size of groups they contain, to show that variation in group size, and in particular small groups, can influence sexual selection. Specifically, I show that null expectations for the operation of pre- and postcopulatory sexual selection is governed by the size of groups within populations because smaller group sizes constrain the structure of sexual networks leading to reinforcing episodes of pre- and postcopulatory sexual selection. Given broad variation in group structure in nature and the tendency for experimental sexual selection research to study replicate small groups, these effects have implications for our understanding of the operation of sexual selection in polyandrous populations.
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Affiliation(s)
- Grant C. McDonald
- Department of EcologyUniversity of Veterinary Medicine BudapestBudapestHungary
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9
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Erofeeva MN, Vasilieva NA, Ananyeva MS, Klyuchnikova PS, Naidenko SV. Meeting with a male can lead to stress: female reaction to a pairing with a partner in Felidae. Behav Processes 2023; 208:104876. [PMID: 37059370 DOI: 10.1016/j.beproc.2023.104876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 04/10/2023] [Accepted: 04/11/2023] [Indexed: 04/16/2023]
Abstract
The aim of this study was to test the hypothesis that the level of sexual dimorphism modulates the effects of male-female social interaction on the female physiological condition in felids. We predicted that: 1 - contacts of females with males in species with low level of sexual dimorphism in body size will not lead to significant changes in the activity of the hypothalamus-pituitary-adrenal axis (female stress); 2 - contacts of females with males in species with a high level of sexual dimorphism can result in significant increase in the cortisol level in females. Our study did not support these hypotheses. Despite the fact that sexual dimorphism influenced partner relationships, changes of the activity of HPA in response to social interaction with a partner appeared to be determined by the biology of the species rather than by the degree of sexual dimorphism. In species with unexpressed sexual dimorphism in body size, females determined the character of relationships in the pair. In species with pronounced sexual dimorphism biased towards males, the pattern of relationships was determined by males. However, meeting a partner led to increased cortisol levels in females not in pairs with pronounced sexual dimorphism, but in pairs with a high frequency of partner interactions. This frequency was determined by the species life history and was probably related to the seasonality of reproduction and the degree of monopolization of the home range.
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Affiliation(s)
- Maryia N Erofeeva
- Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia.
| | - Nina A Vasilieva
- Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia.
| | | | | | - Sergey V Naidenko
- Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia.
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10
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Kappeler PM, Benhaiem S, Fichtel C, Fromhage L, Höner OP, Jennions MD, Kaiser S, Krüger O, Schneider JM, Tuni C, van Schaik J, Goymann W. Sex roles and sex ratios in animals. Biol Rev Camb Philos Soc 2023; 98:462-480. [PMID: 36307924 DOI: 10.1111/brv.12915] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 10/12/2022] [Accepted: 10/14/2022] [Indexed: 11/29/2022]
Abstract
In species with separate sexes, females and males often differ in their morphology, physiology and behaviour. Such sex-specific traits are functionally linked to variation in reproductive competition, mate choice and parental care, which have all been linked to sex roles. At the 150th anniversary of Darwin's theory on sexual selection, the question of why patterns of sex roles vary within and across species remains a key topic in behavioural and evolutionary ecology. New theoretical, experimental and comparative evidence suggests that variation in the adult sex ratio (ASR) is a key driver of variation in sex roles. Here, we first define and discuss the historical emergence of the sex role concept, including recent criticisms and rebuttals. Second, we review the various sex ratios with a focus on ASR, and explore its theoretical links to sex roles. Third, we explore the causes, and especially the consequences, of biased ASRs, focusing on the results of correlational and experimental studies of the effect of ASR variation on mate choice, sexual conflict, parental care and mating systems, social behaviour, hormone physiology and fitness. We present evidence that animals in diverse societies are sensitive to variation in local ASR, even on short timescales, and propose explanations for conflicting results. We conclude with an overview of open questions in this field integrating demography, life history and behaviour.
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Affiliation(s)
- Peter M Kappeler
- Behavioral Ecology and Sociobiology Unit, German Primate Center - Leibniz Institute of Primatology, Kellnerweg 4, 37077, Göttingen, Germany
- Department of Sociobiology/Anthropology, University of Göttingen, Kellnerweg 6, 37077, Göttingen, Germany
| | - Sarah Benhaiem
- Department of Ecological Dynamics, Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Strasse 17, D-10315, Berlin, Germany
| | - Claudia Fichtel
- Behavioral Ecology and Sociobiology Unit, German Primate Center - Leibniz Institute of Primatology, Kellnerweg 4, 37077, Göttingen, Germany
| | - Lutz Fromhage
- Department of Biological and Environmental Science, Ambiotica, University of Jyväskylä, PO Box 35, 40014, Jyväskylä, Finland
| | - Oliver P Höner
- Department of Evolutionary Ecology, Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Strasse 17, D-10315, Berlin, Germany
| | - Michael D Jennions
- Division of Ecology & Evolution, Research School of Biology, ANU College of Science, The Australian National University, RN Robertson Building, 46 Sullivans Creek Road, Canberra, ACT, 2600, Australia
| | - Sylvia Kaiser
- Department of Behavioural Biology, University of Münster, Badestr. 13, 48149, Münster, Germany
| | - Oliver Krüger
- Department of Animal Behavior, Bielefeld University, Morgenbreede 45, 33615, Bielefeld, Germany
| | - Jutta M Schneider
- Department of Biology, Institute of Zoology, Universität Hamburg, Martin-Luther-King Platz 3, 20146, Hamburg, Germany
| | - Cristina Tuni
- Department of Biology II, Ludwig Maximilians University of Munich, Großhaderner Str 2, 82152, Planegg-Martinsried, Germany
| | - Jaap van Schaik
- Applied Zoology and Nature Conservation, University of Greifswald, Loitzer Str. 26, 17489, Greifswald, Germany
| | - Wolfgang Goymann
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Eberhard-Gwinner-Str. 6a, D-82319, Seewiesen, Germany
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11
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Benenson JF, Markovits H. Married women with children experience greater intrasexual competition than their male counterparts. Sci Rep 2023; 13:4498. [PMID: 36934175 PMCID: PMC10024730 DOI: 10.1038/s41598-023-31816-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 03/17/2023] [Indexed: 03/20/2023] Open
Abstract
Human males are considered to be more competitive than females. However, females must also compete for resources necessary for their own and their offsprings' survival. Since females use more indirect forms of competition than males, comparing observable forms of competition may be misleading. One critical driver of competition is resource asymmetry. Since competition occurs primarily within sex, reactions to resource asymmetry with same-sex peers should provide an important measure of competitiveness. We asked 596 married participants, 25-45 years of age with at least one child from three different countries to evaluate how same-sex individuals they know would react to a target individual who had a valuable resource that the same-sex individuals did not have. Half the participants evaluated reactions to same-sex targets, while the other half evaluated reactions to other-sex targets. Participants reported that women would react more negatively than men to resource asymmetry with same-sex targets, but not other-sex targets. These results suggest that women may be even more competitive than men in contexts when important resources related to reproductive success are at stake.
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Affiliation(s)
- Joyce F Benenson
- Department of Human Evolutionary Biology, Harvard University, Cambridge, 02138, USA.
| | - Henry Markovits
- Département de Psychologie, Université du Québec à Montréal, Montréal, H3C 3P8, Canada
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12
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Volzke S, Cleeland JB, Hindell MA, Corney SP, Wotherspoon SJ, McMahon CR. Extreme polygyny results in intersex differences in age-dependent survival of a highly dimorphic marine mammal. ROYAL SOCIETY OPEN SCIENCE 2023; 10:221635. [PMID: 36968236 PMCID: PMC10031410 DOI: 10.1098/rsos.221635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 03/02/2023] [Indexed: 06/18/2023]
Abstract
Developmental differences in vital rates are especially profound in polygamous mating systems. Southern elephant seals (Mirounga leonina) are highly dimorphic and extremely polygynous marine mammals. A demographic model, supported by long-term capture-mark-recapture records, investigated the influence of sex and age on survival in this species. The study revealed clear differences between female and male age-dependent survival rates. Overall juvenile survival estimates were stable around 80-85% for both sexes. However, male survival estimates were 5-10% lower than females in the same age classes until 8 years of age. At this point, male survival decreased rapidly to 50% ± 10% while female estimates remained constant at 80% ± 5%. Different energetic requirements could underpin intersex differences in adult survival. However, the species' strong sexual dimorphism diverges during early juvenile development when sex-specific survival rates were less distinct. Maximizing growth is especially advantageous for males, with size being a major determinant of breeding probability. Maturing males may employ a high-risk high-reward foraging strategy to compensate for extensive sexual selection pressures and sex-specific energetic needs. Our findings suggest sex-specific adult survival is a result of in situ ecological interactions and evolutionary specialization associated with being a highly polygynous marine predator.
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Affiliation(s)
- Sophia Volzke
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7005, Australia
- Australian Antarctic Division, Department of Agriculture, Water and the Environment, Kingston, TAS 7050, Australia
| | - Jaimie B. Cleeland
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7005, Australia
- Australian Antarctic Division, Department of Agriculture, Water and the Environment, Kingston, TAS 7050, Australia
| | - Mark A. Hindell
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7005, Australia
| | - Stuart P. Corney
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7005, Australia
- Centre for Marine Socioecology, University of Tasmania, Hobart, TAS 7005, Australia
- Australian Antarctic Partnership Program, University of Tasmania, Hobart, TAS 7005, Australia
| | - Simon J. Wotherspoon
- Australian Antarctic Division, Department of Agriculture, Water and the Environment, Kingston, TAS 7050, Australia
| | - Clive R. McMahon
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7005, Australia
- IMOS Animal Tagging, Sydney Institute of Marine Science, Mosman, NSW 2088, Australia
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13
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Gutiérrez F, Valdesoiro F. The evolution of personality disorders: A review of proposals. Front Psychiatry 2023; 14:1110420. [PMID: 36793943 PMCID: PMC9922784 DOI: 10.3389/fpsyt.2023.1110420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 01/12/2023] [Indexed: 02/02/2023] Open
Abstract
Personality disorders (PDs) are currently considered dysfunctions. However, personality differences are older than humanity and are ubiquitous in nature, from insects to higher primates. This suggests that a number of evolutionary mechanisms-other than dysfunctions-may be able to maintain stable behavioral variation in the gene pool. First of all, apparently maladaptive traits may actually improve fitness by enabling better survival or successful mating or reproduction, as exemplified by neuroticism, psychopathy, and narcissism. Furthermore, some PDs may harm important biological goals while facilitating others, or may be globally beneficial or detrimental depending on environmental circumstances or body condition. Alternatively, certain traits may form part of life history strategies: Coordinated suites of morphological, physiological and behavioral characters that optimize fitness through alternative routes and respond to selection as a whole. Still others may be vestigial adaptations that are no longer beneficial in present times. Finally, variation may be adaptative in and by itself, as it reduces competition for finite resources. These and other evolutionary mechanisms are reviewed and illustrated through human and non-human examples. Evolutionary theory is the best-substantiated explanatory framework across the life sciences, and may shed light on the question of why harmful personalities exist at all.
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Affiliation(s)
- Fernando Gutiérrez
- Hospital Clínic de Barcelona, Institute of Neuroscience, Barcelona, Spain
- Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
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14
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Kramer KL. Female cooperation: evolutionary, cross-cultural and ethnographic evidence. Philos Trans R Soc Lond B Biol Sci 2023; 378:20210425. [PMID: 36440565 PMCID: PMC9703230 DOI: 10.1098/rstb.2021.0425] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 08/11/2022] [Indexed: 11/29/2022] Open
Abstract
Women and girls cooperate with each other across many domains and at many scales. However, much of this information is buried in the ethnographic record and has been overlooked in theoretic constructions of the evolution of human sociality and cooperation. The assumed primacy of male bonding, hunting, patrilocality and philopatry has dominated the discussion of cooperation without balanced consideration. A closer look at the ethnographic record reveals that in addition to cooperative childcare and food production, women and girls collectively form coalitions, have their own cooperative political, ceremonial, economic and social institutions, and develop female-based exchange and support networks. The numerous ethnographic examples of female cooperation urge reconsideration of gender stereotypes and the limits of female cooperation. This review brings together theoretic, cross-cultural and cross-lifespan research on female cooperation to present a more even and empirically supported view of female sociality. Following the lead from trends in evolutionary biology and sexual selection theory, the hope going forward is that the focus shifts from rote characterizations of sex differences to highlighting sources of variation and conditions that enhance or constrain female cooperative engagement. This article is part of the theme issue 'Cooperation among women: evolutionary and cross-cultural perspectives'.
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Affiliation(s)
- Karen L. Kramer
- Department of Anthropology, University of Utah, Salt Lake City, UT 84112, USA
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15
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Mikula O, Macholán M, Ďureje Ľ, Hiadlovská Z, Daniszová K, Janotová K, Vošlajerová Bímová B. House mouse subspecies do differ in their social structure. Ecol Evol 2022; 12:e9683. [PMID: 36590341 PMCID: PMC9797468 DOI: 10.1002/ece3.9683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 10/17/2022] [Accepted: 12/08/2022] [Indexed: 12/31/2022] Open
Abstract
It is widely acknowledged that population structure can have a substantial impact on evolutionary trajectories. In social animals, this structure is strongly influenced by relationships among the population members, so studies of differences in social structure between diverging populations or nascent species are of prime interest. Ideal models for such a study are two house mouse subspecies, Mus musculus musculus and M. m. domesticus, meeting in Europe along a secondary contact zone. Though the latter subspecies has usually been supposed to form tighter and more isolated social units than the former, the evidence is still inconclusive. Here, we carried out a series of radiofrequency identification experiments in semi-natural enclosures to gather large longitudinal data sets on individual mouse movements. The data were summarized in the form of uni- and multi-layer social networks. Within them, we could delimit and describe the social units ("modules"). While the number of estimated units was similar in both subspecies, domesticus revealed a more "modular" structure. This subspecies also showed more intramodular social interactions, higher spatial module separation, higher intramodular persistence of parent-offspring contacts, and lower multiple paternity, suggesting more effective control of dominant males over reproduction. We also demonstrate that long-lasting modules can be identified with basic reproductive units or demes. We thus provide the first robust evidence that the two subspecies differ in their social structure and dynamics of the structure formation.
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Affiliation(s)
- Ondřej Mikula
- Laboratory of Mammalian Evolutionary Genetics, Institute of Animal Physiology and GeneticsCzech Academy of SciencesBrnoCzech Republic,Institute of Vertebrate BiologyCzech Academy of SciencesResearch Facility StudenecBrnoCzech Republic
| | - Miloš Macholán
- Laboratory of Mammalian Evolutionary Genetics, Institute of Animal Physiology and GeneticsCzech Academy of SciencesBrnoCzech Republic,Department of Botany and Zoology, Faculty of ScienceMasaryk UniversityBrnoCzech Republic
| | - Ľudovít Ďureje
- Institute of Vertebrate BiologyCzech Academy of SciencesResearch Facility StudenecBrnoCzech Republic
| | - Zuzana Hiadlovská
- Laboratory of Mammalian Evolutionary Genetics, Institute of Animal Physiology and GeneticsCzech Academy of SciencesBrnoCzech Republic
| | - Kristina Daniszová
- Laboratory of Mammalian Evolutionary Genetics, Institute of Animal Physiology and GeneticsCzech Academy of SciencesBrnoCzech Republic
| | - Kateřina Janotová
- Institute of Vertebrate BiologyCzech Academy of SciencesResearch Facility StudenecBrnoCzech Republic
| | - Barbora Vošlajerová Bímová
- Laboratory of Mammalian Evolutionary Genetics, Institute of Animal Physiology and GeneticsCzech Academy of SciencesBrnoCzech Republic
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16
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What do evolutionary researchers believe about human psychology and behavior? EVOL HUM BEHAV 2022. [DOI: 10.1016/j.evolhumbehav.2022.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
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17
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Sexual selection for males with beneficial mutations. Sci Rep 2022; 12:12613. [PMID: 35871224 PMCID: PMC9308816 DOI: 10.1038/s41598-022-16002-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 07/04/2022] [Indexed: 11/08/2022] Open
Abstract
Sexual selection is the process by which traits providing a mating advantage are favoured. Theoretical treatments of the evolution of sex by sexual selection propose that it operates by reducing the load of deleterious mutations. Here, we postulate instead that sexual selection primarily acts through females preferentially mating with males carrying beneficial mutations. We used simulation and analytical modelling to investigate the evolutionary dynamics of beneficial mutations in the presence of sexual selection. We found that female choice for males with beneficial mutations had a much greater impact on genetic quality than choice for males with low mutational load. We also relaxed the typical assumption of a fixed mutation rate. For deleterious mutations, mutation rate should always be minimized, but when rare beneficial mutations can occur, female choice for males with those rare beneficial mutations could overcome a decline in average fitness and allow an increase in mutation rate. We propose that sexual selection for beneficial mutations could overcome the ‘two-fold cost of sex’ much more readily than choice for males with low mutational load and may therefore be a more powerful explanation for the prevalence of sexual reproduction than the existing theory. If sexual selection results in higher fitness at higher mutation rates, and if the variability produced by mutation itself promotes sexual selection, then a feedback loop between these two factors could have had a decisive role in driving adaptation.
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18
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Levy DA. Optimizing the social utility of judicial punishment: An evolutionary biology and neuroscience perspective. Front Hum Neurosci 2022; 16:967090. [PMID: 36171873 PMCID: PMC9511021 DOI: 10.3389/fnhum.2022.967090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Accepted: 08/24/2022] [Indexed: 11/13/2022] Open
Abstract
Punishment as a response to impairment of individual or group welfare may be found not only among humans but also among a wide range of social animals. In some cases, acts of punishment serve to increase social cooperation among conspecifics. Such phenomena motivate the search for the biological foundations of punishment among humans. Of special interest are cases of pro-social punishment of individuals harming others. Behavioral studies have shown that in economic games people punish exploiters even at a cost to their own welfare. Additionally, neuroimaging studies have reported activity during the planning of such punishment in brain areas involved in the anticipation of reward. Such findings hint that there is an evolutionarily honed basic drive to punish social offenders. I argue that the transfer of punishment authority from the individual to the group requires that social offenders be punished as a public good, even if such punishment is not effective as retribution or deterrent. Furthermore, the social need for punishment of offenders has implications for alternatives to incarceration, publicity of punishment, and judicial structure.
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Affiliation(s)
- Daniel A. Levy
- Baruch Ivcher School of Psychology, Reichman University – IDC, Herzliya, Israel
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19
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Evolution of reduced mate harming tendency of males in Drosophila melanogaster populations selected for faster life history. Behav Ecol Sociobiol 2022. [DOI: 10.1007/s00265-022-03187-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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20
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Casto KV, Leininger EC, Tan T. Teaching About Sex and Gender in Neuroscience: More Than Meets the "XY". JOURNAL OF UNDERGRADUATE NEUROSCIENCE EDUCATION : JUNE : A PUBLICATION OF FUN, FACULTY FOR UNDERGRADUATE NEUROSCIENCE 2022; 20:A191-A206. [PMID: 38323054 PMCID: PMC10653250 DOI: 10.59390/azvz2988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 07/06/2021] [Accepted: 08/09/2021] [Indexed: 02/08/2024]
Abstract
Offering courses on the neuroscience of sex and gender can help support an inclusive curriculum in neuroscience. At the same time, developing and teaching such courses can be daunting to even the most enthusiastic educators, given the subject's complexities, nuances, and the difficult conversations that it invites. The authors of this article have all developed and taught such courses from different perspectives. Our aim is to provide educators with an overview of important conceptual topics as well as a comprehensive, but non-exhaustive, guide to resources for teaching about sex/gender in neuroscience based on our collective experience teaching courses on the topic. After defining vital terminology and briefly reviewing the biology of sex and sex determination, we describe some common topics within the field and contrast our current nuanced understandings from outdated misconceptions in the field. We review how (mis)representation of the neuroscience of sex/gender serves as a case study for how scientific results are communicated and disseminated. We consider how contextualization of sex/gender neuroscience research within a broader historical and societal framework can give students a wider perspective on the enterprise of science. Finally, we conclude with a brief discussion on how to choose learning goals for your course and implementation notes.
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Affiliation(s)
- Kathleen V Casto
- Division of Social Sciences, New College of Florida, Sarasota, FL 34243
| | | | - Taralyn Tan
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115
- PhD Program in Neuroscience, Harvard University, Cambridge, MA 02138
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21
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22
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Carlitz EHD, Lindholm AK, Gao W, Kirschbaum C, König B. Steroid hormones in hair and fresh wounds reveal sex specific costs of reproductive engagement and reproductive success in wild house mice (Mus musculus domesticus). Horm Behav 2022; 138:105102. [PMID: 34998227 DOI: 10.1016/j.yhbeh.2021.105102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 10/19/2021] [Accepted: 12/12/2021] [Indexed: 11/30/2022]
Abstract
Not only males but also females compete over reproduction. In a population of free-living house mice (Mus musculus domesticus), we analyzed how (metabolic) costs of aggressive interactions (reflected in fresh wounds and long-term corticosterone concentrations in hair) are predicted by individual reproductive physiology and reproductive success in males and females. Over eight years, we studied wounds and reproduction of more than 2800 adults under naturally varying environmental conditions and analyzed steroid hormones from more than 1000 hair samples. Hair corticosterone were higher and wounds more frequent in males than females. In males, wound occurrence increased with increasing breeding activity in the population, without affecting hair corticosterone levels. Unexpectedly, individual male reproductive success did not predict wounds, while hair corticosterone increased with increasing levels of hair testosterone and reproductive success. High corticosterone in hair of males might therefore reflect metabolic costs of fighting over reproduction. In females, hair corticosterone was generally lower than in males and high levels did not impede pregnancy. Reproductive investment (reflected in hair progesterone) was dissociated from reproductive success. Occasional wounds in females indicated individuals without recent reproductive success and revealed reproductive competition, presumably driven by instability in the social environment. In both sexes, corticosterone increased with age, but there was no evidence that received overt aggression, as indicated by wounds or elevated corticosterone, suppressed reproductive physiology. Our results diverge from laboratory findings and emphasize the need to also study animals in their natural environment in order to understand the complexity of their behavioral physiology.
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Affiliation(s)
- Esther H D Carlitz
- Department of Psychology, Biological Psychology, Technical University of Dresden, Dresden, Germany.
| | - Anna K Lindholm
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Wei Gao
- Department of Psychology, Biological Psychology, Technical University of Dresden, Dresden, Germany
| | - Clemens Kirschbaum
- Department of Psychology, Biological Psychology, Technical University of Dresden, Dresden, Germany
| | - Barbara König
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
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23
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Yu F, Wang X, Huang C, Li Z. Unexpected male choosiness: condition-dependent mating strategies of crayfish. Anim Behav 2022. [DOI: 10.1016/j.anbehav.2021.11.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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24
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Affiliation(s)
- Ash T Zemenick
- University of California Berkeley's Sagehen Creek Field Station, Truckee, California, United States
| | - Shaun Turney
- university-educated parents, currently on paternity leave from his work as a non-tenure-track course lecturer, biology
| | - Alex J Webster
- University of New Mexico's Department of Biology, Albuquerque, New Mexico, United States
| | | | - Marjorie G Weber
- Michigan State University's Plant Biology Department and Program in Ecology, Evolution, and Behavior, East Lansing, Michigan, United States
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25
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Murtazina EP, Buyanova IS, Ginzburg-Shik YA. Experimental Models of the Dyadic Operant Behavior of Rats in Different Social Contexts. BIOL BULL+ 2021. [DOI: 10.1134/s1062359021090144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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26
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Evans JC, Lindholm AK, König B. Family dynamics reveal that female house mice preferentially breed in their maternal community. Behav Ecol 2021. [DOI: 10.1093/beheco/arab128] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Whether females breed in their natal group is an important factor in the evolution of extended families in animal sociality. Breeding in natal groups comes with costs and benefits, depending on group size and presence of older relatives, including mothers. Studying the consequences of breeding in the natal versus another group provides insight into the decisions and trade-offs governing the formation and structure of family groups. We investigated the family dynamics of a population of free-ranging commensal house mice. Using dynamic community detection on long-term datasets, we determined which females first bred in their natal group. We then looked at how this influenced breeding success. We found most females (77%) exhibited strong philopatry, breeding in their natal groups. Breeding elsewhere was only somewhat predictable at very large and very small group sizes. Despite their philopatric preference, breeding elsewhere made no difference in how quickly and successfully a female bred. However, presence of their mother did lead females to breed sooner when born during high breeding activity, when competition over reproduction is high. Based on these results, potential loss of reproductive success from leaving the natal group does not seem to be the main driver of philopatry in female house mice. The effect of the presence of mothers suggests that benefiting from established social connections promotes breeding in the natal group. Mothers providing benefits also implies a lack of conflict between generations, which will be important for the development of stable social groups.
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Affiliation(s)
- Julian C Evans
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Anna K Lindholm
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Barbara König
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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27
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Garcia de la Chica A, Wood DB, Rotundo M, Fernandez‐Duque E. Responses of a pair‐living, sexually monogamous primate to the simulated presence of solitary individuals: A field playback experiment. Ethology 2021. [DOI: 10.1111/eth.13222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
| | - David Bechtel Wood
- Owl Monkey Project‐ Fundación ECO Formosa Argentina
- Yale University New Haven Connecticut USA
| | | | - Eduardo Fernandez‐Duque
- Owl Monkey Project‐ Fundación ECO Formosa Argentina
- Yale University New Haven Connecticut USA
- Universidad de Formosa Formosa Argentina
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28
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Abstract
[Figure: see text].
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29
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Shuker DM, Kvarnemo C. The definition of sexual selection. Behav Ecol 2021; 32:781-794. [PMID: 34695172 PMCID: PMC8528540 DOI: 10.1093/beheco/arab055] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 05/05/2021] [Accepted: 05/11/2021] [Indexed: 11/13/2022] Open
Abstract
Sexual selection is a key component of evolutionary biology. However, from the very formulation of sexual selection by Darwin, the nature and extent of sexual selection have been controversial. Recently, such controversy has led back to the fundamental question of just what sexual selection is. This has included how we incorporate female-female reproductive competition into sexual or natural selection. In this review, we do four things. First, we examine what we want a definition to do. Second, we define sexual selection: sexual selection is any selection that arises from fitness differences associated with nonrandom success in the competition for access to gametes for fertilization. An important outcome of this is that as mates often also offer access to resources, when those resources are the targets of the competition, rather than their gametes, the process should be considered natural rather than sexual selection. We believe this definition encapsulates both much of Darwin's original thinking about sexual selection, and much of how contemporary biologists use the concept of sexual selection. Third, we address alternative definitions, focusing in some detail on the role of female reproductive competition. Fourth, we challenge our definition with a number of scenarios, for instance where natural and sexual selection may align (as in some forms of endurance rivalry), or where differential allocation means teasing apart how fecundity and access to gametes influence fitness. In conclusion, we emphasize that whilst the ecological realities of sexual selection are likely to be complex, the definition of sexual selection is rather simple.
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Affiliation(s)
- David M Shuker
- School of Biology, Harold Mitchell Building, University of St. Andrews, St. Andrews, UK
| | - Charlotta Kvarnemo
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, SE, Sweden
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30
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Balasubramaniam KN, Kaburu SSK, Marty PR, Beisner BA, Bliss-Moreau E, Arlet ME, Ruppert N, Ismail A, Anuar Mohd Sah S, Mohan L, Rattan S, Kodandaramaiah U, McCowan B. Implementing social network analysis to understand the socioecology of wildlife co-occurrence and joint interactions with humans in anthropogenic environments. J Anim Ecol 2021; 90:2819-2833. [PMID: 34453852 DOI: 10.1111/1365-2656.13584] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 08/23/2021] [Indexed: 11/28/2022]
Abstract
Human population expansion into wildlife habitats has increased interest in the behavioural ecology of human-wildlife interactions. To date, however, the socioecological factors that determine whether, when or where wild animals take risks by interacting with humans and anthropogenic factors still remains unclear. We adopt a comparative approach to address this gap, using social network analysis (SNA). SNA, increasingly implemented to determine human impact on wildlife ecology, can be a powerful tool to understand how animal socioecology influences the spatiotemporal distribution of human-wildlife interactions. For 10 groups of rhesus, long-tailed and bonnet macaques (Macaca spp.) living in anthropogenically impacted environments in Asia, we collected data on human-macaque interactions, animal demographics, and macaque-macaque agonistic and affiliative social interactions. We constructed 'human co-interaction networks' based on associations between macaques that interacted with humans within the same time and spatial locations, and social networks based on macaque-macaque allogrooming behaviour, affiliative behaviours of short duration (agonistic support, lip-smacking, silent bare-teeth displays and non-sexual mounting) and proximity. Pre-network permutation tests revealed that, within all macaque groups, specific individuals jointly took risks by repeatedly, consistently co-interacting with humans within and across time and space. GLMMs revealed that macaques' tendencies to co-interact with humans was positively predicted by their tendencies to engage in short-duration affiliative interactions and tolerance of conspecifics, although the latter varied across species (bonnets>rhesus>long-tailed). Male macaques were more likely to co-interact with humans than females. Neither macaques' grooming relationships nor their dominance ranks predicted their tendencies to co-interact with humans. Our findings suggest that, in challenging anthropogenic environments, less (compared to more) time-consuming forms of affiliation, and additionally greater social tolerance in less ecologically flexible species with a shorter history of exposure to humans, may be key to animals' joint propensities to take risks to gain access to resources. For males, greater exploratory tendencies and less energetically demanding long-term life-history strategies (compared to females) may also influence such joint risk-taking. From conservation and public health perspectives, wildlife connectedness within such co-interaction networks may inform interventions to mitigate zoonosis, and move human-wildlife interactions from conflict towards coexistence.
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Affiliation(s)
- Krishna N Balasubramaniam
- Department of Population Health & Reproduction, School of Veterinary Medicine (SVM), University of California at Davis, Davis, CA, USA
| | - Stefano S K Kaburu
- Department of Biomedical Science and Physiology, Faculty of Science and Engineering, University of Wolverhampton, Wolverhampton, UK
| | - Pascal R Marty
- Department of Population Health & Reproduction, School of Veterinary Medicine (SVM), University of California at Davis, Davis, CA, USA.,Zoo Zürich, Zürich, Switzerland
| | - Brianne A Beisner
- Department of Population Health & Reproduction, School of Veterinary Medicine (SVM), University of California at Davis, Davis, CA, USA.,Animal Resources Division, Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA
| | - Eliza Bliss-Moreau
- Department of Psychology, University of California, Davis, CA, USA.,California National Primate Research Center, University of California, Davis, CA, USA
| | - Malgorzata E Arlet
- Institute of Human Biology and Evolution, Faculty of Biology, Adam Mickiewicz University, Poznan, Poland
| | - Nadine Ruppert
- School of Biological Sciences, Universiti Sains Malaysia, Pulau Pinang, Malaysia.,Malaysian Primatological Society, Kulim, Kedah, Malaysia
| | - Ahmad Ismail
- Department of Biology, Faculty of Science, Universiti Putra Malaysia, Selangor, Malaysia
| | | | - Lalith Mohan
- Himachal Pradesh Forest Department, Shimla, India
| | | | - Ullasa Kodandaramaiah
- IISER-TVM Centre for Research and Education in Ecology and Evolution (ICREEE), School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Vithura, Thiruvananthapuram, India
| | - Brenda McCowan
- Department of Population Health & Reproduction, School of Veterinary Medicine (SVM), University of California at Davis, Davis, CA, USA.,California National Primate Research Center, University of California, Davis, CA, USA
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31
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Smith JE, von Rueden CR, van Vugt M, Fichtel C, Kappeler PM. An Evolutionary Explanation for the Female Leadership Paradox. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.676805] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Social influence is distributed unequally between males and females in many mammalian societies. In human societies, gender inequality is particularly evident in access to leadership positions. Understanding why women historically and cross-culturally have tended to be under-represented as leaders within human groups and organizations represents a paradox because we lack evidence that women leaders consistently perform worse than men. We also know that women exercise overt influence in collective group-decisions within small-scale human societies, and that female leadership is pervasive in particular contexts across non-human mammalian societies. Here, we offer a transdisciplinary perspective on this female leadership paradox. Synthesis of social science and biological literatures suggests that females and males, on average, differ in why and how they compete for access to political leadership in mixed-gender groups. These differences are influenced by sexual selection and are moderated by socioecological variation across development and, particularly in human societies, by culturally transmitted norms and institutions. The interplay of these forces contributes to the emergence of female leaders within and across species. Furthermore, females may regularly exercise influence on group decisions in less conspicuous ways and different domains than males, and these underappreciated forms of leadership require more study. We offer a comprehensive framework for studying inequality between females and males in access to leadership positions, and we discuss the implications of this approach for understanding the female leadership paradox and for redressing gender inequality in leadership in humans.
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32
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Liker A, Bókony V, Pipoly I, Lemaître JF, Gaillard JM, Székely T, Freckleton RP. Evolution of large males is associated with female-skewed adult sex ratios in amniotes. Evolution 2021; 75:1636-1649. [PMID: 34021590 DOI: 10.1111/evo.14273] [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: 09/24/2020] [Revised: 04/30/2021] [Accepted: 05/05/2021] [Indexed: 12/30/2022]
Abstract
Body size often differs between the sexes (leading to sexual size dimorphism, SSD), as a consequence of differential responses by males and females to selection pressures. Adult sex ratio (ASR, the proportion of males in the adult population) should influence SSD because ASR relates to both the number of competitors and available mates, which shape the intensity of mating competition and thereby promotes SSD evolution. However, whether ASR correlates with SSD variation among species has not been yet tested across a broad range of taxa. Using phylogenetic comparative analyses of 462 amniotes (i.e., reptiles, birds, and mammals), we fill this knowledge gap by showing that male bias in SSD increases with increasingly female-skewed ASRs in both mammals and birds. This relationship is not explained by the higher mortality of the larger sex because SSD is not associated with sex differences in either juvenile or adult mortality. Phylogenetic path analysis indicates that higher mortality in one sex leads to skewed ASR, which in turn may generate selection for SSD biased toward the rare sex. Taken together, our findings provide evidence that skewed ASRs in amniote populations can result in the rarer sex evolving large size to capitalize on enhanced mating opportunities.
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Affiliation(s)
- András Liker
- MTA-PE Evolutionary Ecology Research Group, University of Pannonia, Veszprém, H-8210, Hungary.,Behavioral Ecology Research Group, Center for Natural Sciences, University of Pannonia, Veszprém, H-8210, Hungary
| | - Veronika Bókony
- Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Eötvös Loránd Research Network, Budapest, H-1022, Hungary
| | - Ivett Pipoly
- MTA-PE Evolutionary Ecology Research Group, University of Pannonia, Veszprém, H-8210, Hungary.,Behavioral Ecology Research Group, Center for Natural Sciences, University of Pannonia, Veszprém, H-8210, Hungary
| | - Jean-Francois Lemaître
- Université Lyon 1, CNRS, Laboratoire de Biométrie et Biologie Évolutive UMR 5558, Villeurbanne, F-69622, France
| | - Jean-Michel Gaillard
- Université Lyon 1, CNRS, Laboratoire de Biométrie et Biologie Évolutive UMR 5558, Villeurbanne, F-69622, France
| | - Tamás Székely
- Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath, BA2 7AY, United Kingdom.,Department of Evolutionary Zoology and Human Biology, University of Debrecen, Debrecen, H-4032, Hungary
| | - Robert P Freckleton
- Department of Animal and Plant Sciences, Alfred Denny Building, University of Sheffield, Sheffield, S10 2TN, United Kingdom
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Low fundamental and formant frequencies predict fighting ability among male mixed martial arts fighters. Sci Rep 2021; 11:905. [PMID: 33441596 PMCID: PMC7806622 DOI: 10.1038/s41598-020-79408-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 12/08/2020] [Indexed: 01/29/2023] Open
Abstract
Human voice pitch is highly sexually dimorphic and eminently quantifiable, making it an ideal phenotype for studying the influence of sexual selection. In both traditional and industrial populations, lower pitch in men predicts mating success, reproductive success, and social status and shapes social perceptions, especially those related to physical formidability. Due to practical and ethical constraints however, scant evidence tests the central question of whether male voice pitch and other acoustic measures indicate actual fighting ability in humans. To address this, we examined pitch, pitch variability, and formant position of 475 mixed martial arts (MMA) fighters from an elite fighting league, with each fighter's acoustic measures assessed from multiple voice recordings extracted from audio or video interviews available online (YouTube, Google Video, podcasts), totaling 1312 voice recording samples. In four regression models each predicting a separate measure of fighting ability (win percentages, number of fights, Elo ratings, and retirement status), no acoustic measure significantly predicted fighting ability above and beyond covariates. However, after fight statistics, fight history, height, weight, and age were used to extract underlying dimensions of fighting ability via factor analysis, pitch and formant position negatively predicted "Fighting Experience" and "Size" factor scores in a multivariate regression model, explaining 3-8% of the variance. Our findings suggest that lower male pitch and formants may be valid cues of some components of fighting ability in men.
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Šmejkal M, Bartoň D, Brabec M, Sajdlová Z, Souza AT, Moraes KR, Soukalová K, Blabolil P, Vejřík L, Kubečka J. Climbing up the ladder: male reproductive behaviour changes with age in a long-lived fish. Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-020-02961-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Abstract
High reproductive performance is the key attribute of male fitness, especially due to the high reproductive skew among the males of most animal species. Males of long-lived iteroparous species have opportunities to improve upon their previous reproductive attempts with increasing age. We collected individual-specific reproductive behaviour and age data on a cyprinid fish, the asp (Leuciscus aspius), from 2015 to 2019. We tested whether males changed their performance over time using a unique dataset where individual performance was recorded yearly with passive telemetry. Individual fish behaviour was tracked from one to five reproductive seasons at least a year after the tagging. Fish were scored by measures of quality (first arrival time, number of visits and time spent in the reproductive grounds, and encountered proportion of males to all adult fish). In general, fish improved in the first three metrics with age, suggesting a shift towards behaviours likely to enhance reproductive success as individuals aged. A larger size at tagging was predictive of earlier fish arrival on the spawning ground in subsequent years. Our study therefore demonstrates the importance of age as a factor when considering the potential reproductive success of long-lived fish species.
Significance statement
High reproductive performance is the key attribute of male fitness. Males of long-lived species reproducing multiple times in their life have opportunities to improve upon their previous reproductive performance with increasing age. In this 5-year study, we tracked a large cyprinid fish with telemetry systems during their reproduction. We investigated the age-related behavioural changes in males and demonstrated the improvement of male reproductive timing and length of stay with potential repercussions for male’s reproductive output. We emphasize the importance of old and experienced individuals among the fish population, which are often targeted and selectively removed from the human-managed waters.
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35
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Sexual Selection: Evolutionary Foundations. Anim Behav 2021. [DOI: 10.1007/978-3-030-82879-0_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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36
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Balasubramaniam KN, Marty PR, Samartino S, Sobrino A, Gill T, Ismail M, Saha R, Beisner BA, Kaburu SSK, Bliss-Moreau E, Arlet ME, Ruppert N, Ismail A, Sah SAM, Mohan L, Rattan SK, Kodandaramaiah U, McCowan B. Impact of individual demographic and social factors on human-wildlife interactions: a comparative study of three macaque species. Sci Rep 2020; 10:21991. [PMID: 33319843 PMCID: PMC7738552 DOI: 10.1038/s41598-020-78881-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 12/01/2020] [Indexed: 11/17/2022] Open
Abstract
Despite increasing conflict at human-wildlife interfaces, there exists little research on how the attributes and behavior of individual wild animals may influence human-wildlife interactions. Adopting a comparative approach, we examined the impact of animals' life-history and social attributes on interactions between humans and (peri)urban macaques in Asia. For 10 groups of rhesus, long-tailed, and bonnet macaques, we collected social behavior, spatial data, and human-interaction data for 11-20 months on pre-identified individuals. Mixed-model analysis revealed that, across all species, males and spatially peripheral individuals interacted with humans the most, and that high-ranking individuals initiated more interactions with humans than low-rankers. Among bonnet macaques, but not rhesus or long-tailed macaques, individuals who were more well-connected in their grooming network interacted more frequently with humans than less well-connected individuals. From an evolutionary perspective, our results suggest that individuals incurring lower costs related to their life-history (males) and resource-access (high rank; strong social connections within a socially tolerant macaque species), but also higher costs on account of compromising the advantages of being in the core of their group (spatial periphery), are the most likely to take risks by interacting with humans in anthropogenic environments. From a conservation perspective, evaluating individual behavior will better inform efforts to minimize conflict-related costs and zoonotic-risk.
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Affiliation(s)
- Krishna N Balasubramaniam
- Department of Population Health and Reproduction, School of Veterinary Medicine (SVM), University of California at Davis, Davis, CA, 95616, USA.
| | - Pascal R Marty
- Department of Population Health and Reproduction, School of Veterinary Medicine (SVM), University of California at Davis, Davis, CA, 95616, USA
- School of Biological Sciences, Universiti Sains Malaysia, 11800, Pulau Pinang, Malaysia
| | - Shelby Samartino
- Department of Population Health and Reproduction, School of Veterinary Medicine (SVM), University of California at Davis, Davis, CA, 95616, USA
- Department of Anthropology, University of Texas at San Antonio, San Antonio, TX, 78249, USA
| | - Alvaro Sobrino
- Department of Population Health and Reproduction, School of Veterinary Medicine (SVM), University of California at Davis, Davis, CA, 95616, USA
- School of Biological Sciences, Universiti Sains Malaysia, 11800, Pulau Pinang, Malaysia
| | - Taniya Gill
- Department of Population Health and Reproduction, School of Veterinary Medicine (SVM), University of California at Davis, Davis, CA, 95616, USA
- Department of Anthropology, University of Delhi, Delhi, 110007, India
| | - Mohammed Ismail
- Department of Population Health and Reproduction, School of Veterinary Medicine (SVM), University of California at Davis, Davis, CA, 95616, USA
- Primate Conservation Group, Oxford Brookes University, Oxford, OX3 0BP, UK
| | - Rajarshi Saha
- Department of Population Health and Reproduction, School of Veterinary Medicine (SVM), University of California at Davis, Davis, CA, 95616, USA
- Institute of Human Biology and Evolution, Faculty of Biology, Adam Mickiewicz University, 61614, Poznan, Poland
| | - Brianne A Beisner
- Department of Population Health and Reproduction, School of Veterinary Medicine (SVM), University of California at Davis, Davis, CA, 95616, USA
- California National Primate Research Center, University of California, Davis, CA, 95616, USA
| | - Stefano S K Kaburu
- Department of Population Health and Reproduction, School of Veterinary Medicine (SVM), University of California at Davis, Davis, CA, 95616, USA
- Department of Biomedical Science and Physiology, Faculty of Science and Engineering, University of Wolverhampton, Wolverhampton, WV1 1LY, UK
| | - Eliza Bliss-Moreau
- California National Primate Research Center, University of California, Davis, CA, 95616, USA
- Department of Psychology and the California National Primate Research Center, University of California, Davis, CA, 95616, USA
| | - Malgorzata E Arlet
- Institute of Human Biology and Evolution, Faculty of Biology, Adam Mickiewicz University, 61614, Poznan, Poland
| | - Nadine Ruppert
- School of Biological Sciences, Universiti Sains Malaysia, 11800, Pulau Pinang, Malaysia
| | - Ahmad Ismail
- Department of Biology, Faculty of Science, Universiti Putra Malaysia, 43400 UPM, Selangor, Malaysia
| | | | - Lalit Mohan
- Himachal Pradesh Forest Department, Shimla, Himachal Pradesh, 171002, India
| | - Sandeep K Rattan
- Himachal Pradesh Forest Department, Shimla, Himachal Pradesh, 171002, India
| | - Ullasa Kodandaramaiah
- IISER-TVM Centre for Research and Education in Ecology and Evolution (ICREEE), School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P.O., Vithura, Thiruvananthapuram, 695551, India
| | - Brenda McCowan
- Department of Population Health and Reproduction, School of Veterinary Medicine (SVM), University of California at Davis, Davis, CA, 95616, USA
- California National Primate Research Center, University of California, Davis, CA, 95616, USA
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37
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Reyes-Ramírez A, Sandoval-García IA, Rocha-Ortega M, Córdoba-Aguilar A. Mutual mate choice and its benefits for both sexes. Sci Rep 2020; 10:19492. [PMID: 33173125 PMCID: PMC7656247 DOI: 10.1038/s41598-020-76615-z] [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: 06/29/2020] [Accepted: 10/30/2020] [Indexed: 11/09/2022] Open
Abstract
In mating interactions, it is common in nature for both sexes to choose simultaneously. However, this mutual mate choice and its consequences for progeny has received relatively little study; an approach where both male and female condition is manipulated is thus desirable. We compared both sexes' preferences in Tenebrio molitor beetles when individual condition varied (healthy vs infected with a fungus), and observed the direct benefits of those preferences. We predicted that: (a) females and males in good condition would prefer high quality mates; (b) preferences would be weaker when the choosing individual is in poor condition (and thus less selective given, for example, time and energetic constrains); and, (c) high quality mates would lay a larger number of total eggs and/or viable eggs than low quality mates. We found that both males and females in good condition were not more likely to choose mates that were also in good condition. However, poor-condition animals were more likely to prefer similar quality animals, while high-condition animals did not necessarily prefer mates of similar condition. Choosing sick males or females had a negative impact on egg number and viability. Our results suggest a non-adaptive mate choice in this species. Possibly, a deteriorated condition may drive individuals to invest more in attracting mates, because their chances of surviving the infection are very low. However, we do not discount the possibility that the fungus is manipulating individuals to increase its transmission during mating.
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Affiliation(s)
- Alicia Reyes-Ramírez
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Apdo. P. 70-275, Circuito Exterior, Ciudad Universitaria, 04510, Coyoacán, Distrito Federal, Mexico
| | - Iván Antonio Sandoval-García
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Apdo. P. 70-275, Circuito Exterior, Ciudad Universitaria, 04510, Coyoacán, Distrito Federal, Mexico
| | - Maya Rocha-Ortega
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Apdo. P. 70-275, Circuito Exterior, Ciudad Universitaria, 04510, Coyoacán, Distrito Federal, Mexico
| | - Alex Córdoba-Aguilar
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Apdo. P. 70-275, Circuito Exterior, Ciudad Universitaria, 04510, Coyoacán, Distrito Federal, Mexico.
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38
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Stångberg J, Immonen E, Moreno PP, Bolund E. Experimentally induced intrasexual mating competition and sex-specific evolution in female and male nematodes. J Evol Biol 2020; 33:1677-1688. [PMID: 32945028 PMCID: PMC7756511 DOI: 10.1111/jeb.13706] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/28/2020] [Accepted: 09/04/2020] [Indexed: 01/01/2023]
Abstract
Sexual dimorphism in life history traits and their trade-offs is widespread among sexually reproducing animals and is strongly influenced by the differences in reproductive strategies between the sexes. We investigated how intrasexual competition influenced specific life history traits, important to fitness and their trade-offs in the outcrossing nematode Caenorhabditis remanei. Here, we altered the strength of sex-specific selection through experimental evolution with increased potential for intrasexual competition by skewing the adult sex ratio towards either females or males (1:10 or 10:1) over 30 generations and subsequently measured the phenotypic response to selection in three traits related to fitness: body size, fecundity and tolerance to heat stress. We observed a greater evolutionary change in females than males for body size and peak fitness, suggesting that females may experience stronger net selection and potentially harbour higher amounts of standing genetic variance compared to males. Our study highlights the importance of investigating direct and indirect effects of intrasexual competition in both sexes in order to capture sex-specific responses and understand the evolution of sexual dimorphism in traits expressed by both sexes.
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Affiliation(s)
- Josefine Stångberg
- Department of Ecology and Genetics, Animal Ecology, Uppsala University, Uppsala, Sweden
| | - Elina Immonen
- Department of Ecology and Genetics, Evolutionary Biology, Uppsala University, Uppsala, Sweden
| | - Pilar Puimedon Moreno
- Department of Ecology and Genetics, Animal Ecology, Uppsala University, Uppsala, Sweden
| | - Elisabeth Bolund
- Department of Ecology and Genetics, Animal Ecology, Uppsala University, Uppsala, Sweden
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39
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Dapper AL, Wade MJ. Relaxed Selection and the Rapid Evolution of Reproductive Genes. Trends Genet 2020; 36:640-649. [PMID: 32713599 DOI: 10.1016/j.tig.2020.06.014] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/22/2020] [Accepted: 06/23/2020] [Indexed: 10/23/2022]
Abstract
Evolutionary genomic studies find that reproductive protein genes, those directly involved in reproductive processes, diversify more rapidly than most other gene categories. Strong postcopulatory sexual selection acting within species is the predominant hypothesis proposed to account for the observed pattern. Recently, relaxed selection due to sex-specific gene expression has also been put forward to explain the relatively rapid diversification. We contend that relaxed selection due to sex-limited gene expression is the correct null model for tests of molecular evolution of reproductive genes and argue that it may play a more significant role in the evolutionary diversification of reproductive genes than previously recognized. We advocate for a re-evaluation of adaptive explanations for the rapid diversification of reproductive genes.
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Affiliation(s)
- Amy L Dapper
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA; Department of Biology, Indiana University, Bloomington, IN 47401, USA.
| | - Michael J Wade
- Department of Biology, Indiana University, Bloomington, IN 47401, USA
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40
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Abstract
AbstractMany organisms studied by evolutionary biologists have different sexes, and the evolution of separate sexes and sexual dimorphisms in morphology and behaviour are central questions in evolutionary biology. Considering scientists to be embedded in a social and cultural context, we are also subjected to the risk of gender-biased assumptions and stereotypical thinking to appear when working on topics related to sexual reproduction and sexual dimorphism. Here we present, for continued discussion, a set of good-practice guidelines aimed at (1) helping to improve researchers’ awareness of gender-biased assumptions underlying language use, generalizations, and interpretation of observations; and (2) providing recommendations to increase transparency, avoid problematic terminology, and improve study designs.
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41
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Fuller J, Ferchaud A, Laporte M, Le Luyer J, Davis TB, Côté SD, Bernatchez L. Absence of founder effect and evidence for adaptive divergence in a recently introduced insular population of white‐tailed deer (
Odocoileus virginianus
). Mol Ecol 2019; 29:86-104. [DOI: 10.1111/mec.15317] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 10/25/2019] [Accepted: 10/29/2019] [Indexed: 12/16/2022]
Affiliation(s)
- Jérémie Fuller
- Département de Biologie Université Laval Québec QC Canada
- Natural Sciences and Engineering Research Council of Canada (NSERC) Research Chair in Integrated Management of the Resources of Anticosti Island and Centre d'Études Nordiques (CEN) Québec QC Canada
- Institut de Biologie Intégrative des Systèmes (IBIS) Université Laval Québec QC Canada
| | - Anne‐Laure Ferchaud
- Institut de Biologie Intégrative des Systèmes (IBIS) Université Laval Québec QC Canada
| | - Martin Laporte
- Institut de Biologie Intégrative des Systèmes (IBIS) Université Laval Québec QC Canada
| | - Jérémy Le Luyer
- Institut de Biologie Intégrative des Systèmes (IBIS) Université Laval Québec QC Canada
| | | | - Steeve D. Côté
- Département de Biologie Université Laval Québec QC Canada
- Natural Sciences and Engineering Research Council of Canada (NSERC) Research Chair in Integrated Management of the Resources of Anticosti Island and Centre d'Études Nordiques (CEN) Québec QC Canada
| | - Louis Bernatchez
- Département de Biologie Université Laval Québec QC Canada
- Institut de Biologie Intégrative des Systèmes (IBIS) Université Laval Québec QC Canada
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42
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Lee AM, Myhre AM, Markussen SS, Engen S, Solberg EJ, Haanes H, Røed K, Herfindal I, Heim M, Saether BE. Decomposing demographic contributions to the effective population size with moose as a case study. Mol Ecol 2019; 29:56-70. [PMID: 31732991 DOI: 10.1111/mec.15309] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 11/01/2019] [Accepted: 11/06/2019] [Indexed: 11/30/2022]
Abstract
Levels of random genetic drift are influenced by demographic factors, such as mating system, sex ratio and age structure. The effective population size (Ne ) is a useful measure for quantifying genetic drift. Evaluating relative contributions of different demographic factors to Ne is therefore important to identify what makes a population vulnerable to loss of genetic variation. Until recently, models for estimating Ne have required many simplifying assumptions, making them unsuitable for this task. Here, using data from a small, harvested moose population, we demonstrate the use of a stochastic demographic framework allowing for fluctuations in both population size and age distribution to estimate and decompose the total demographic variance and hence the ratio of effective to total population size (Ne /N) into components originating from sex, age, survival and reproduction. We not only show which components contribute most to Ne /N currently, but also which components have the greatest potential for changing Ne /N. In this relatively long-lived polygynous system we show that Ne /N is most sensitive to the demographic variance of older males, and that both reproductive autocorrelations (i.e., a tendency for the same individuals to be successful several years in a row) and covariance between survival and reproduction contribute to decreasing Ne /N (increasing genetic drift). These conditions are common in nature and can be caused by common hunting strategies. Thus, the framework presented here has great potential to increase our understanding of the demographic processes that contribute to genetic drift and viability of populations, and to inform management decisions.
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Affiliation(s)
- Aline Magdalena Lee
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Ane Marlene Myhre
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Stine Svalheim Markussen
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Steinar Engen
- Centre for Biodiversity Dynamics, Department of Mathematical Sciences, Norwegian University of Science and Technology, Trondheim, Norway
| | | | - Hallvard Haanes
- Norwegian Radiation and Nuclear Safety Authority (DSA), Oslo, Norway
| | - Knut Røed
- Department of Basic Sciences and Aquatic Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Ivar Herfindal
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Morten Heim
- Norwegian Institute for Nature Research (NINA), Trondheim, Norway
| | - Bernt-Erik Saether
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
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43
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44
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Cassini MH. A mixed model of the evolution of polygyny and sexual size dimorphism in mammals. Mamm Rev 2019. [DOI: 10.1111/mam.12171] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Marcelo H. Cassini
- Laboratorio de Biología del Comportamiento IBYME CONICET Obligado 2490, 1429 Buenos Aires Argentina
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45
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Sæther BE, Engen S. Towards a predictive conservation biology: the devil is in the behaviour. Philos Trans R Soc Lond B Biol Sci 2019; 374:20190013. [PMID: 31352892 PMCID: PMC6710570 DOI: 10.1098/rstb.2019.0013] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/26/2019] [Indexed: 01/21/2023] Open
Abstract
One of the most important challenges in conservation biology is to predict the viability of populations of vulnerable and threatened species. This requires that the demographic stochasticity strongly affecting the ecological and evolutionary dynamics of especially small populations is correctly estimated and modelled. Here, we summarize theoretical evidence showing that the demographic variance in population dynamics is a key parameter determining the probability of extinction and also is directly linked to the magnitude of the genetic drift in the population. The demographic variance is dependent on the mating system, being larger in a polygynous than in monogamous populations. Understanding factors affecting intersexual differences in mating success is therefore essential in explaining variation in the demographic variance. We hypothesize that the strength of sexual selection, for example, quantified by the Bateman gradient, may be a useful predictor of the magnitude of the demographic stochasticity and hence the genetic drift in the population. We provide results from a field study of moose that support this claim. Thus, including central principles from behavioural ecology may increase the reliability of population viability analyses through an improvement of our understanding of factors affecting stochastic influences on population dynamics and evolutionary processes. This article is part of the theme issue 'Linking behaviour to dynamics of populations and communities: application of novel approaches in behavioural ecology to conservation'.
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Affiliation(s)
- Bernt-Erik Sæther
- Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Steinar Engen
- Department of Mathematical Sciences, Centre for Biodiversity Dynamics, Norwegian University of Science and Technology, 7491 Trondheim, Norway
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46
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Henshaw JM, Fromhage L, Jones AG. Sex roles and the evolution of parental care specialization. Proc Biol Sci 2019; 286:20191312. [PMID: 31455191 DOI: 10.1098/rspb.2019.1312] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Males and females are defined by the relative size of their gametes (anisogamy), but secondary sexual dimorphism in fertilization, parental investment and mating competition is widespread and often remarkably stable over evolutionary timescales. Recent theory has clarified the causal connections between anisogamy and the most prevalent differences between the sexes, but deviations from these patterns remain poorly understood. Here, we study how sex differences in parental investment and mating competition coevolve with parental care specialization. Parental investment often consists of two or more distinct activities (e.g. provisioning and defence) and parents may care more efficiently by specializing in a subset of these activities. Our model predicts that efficient care specialization broadens the conditions under which biparental investment can evolve in lineages that historically had uniparental care. Major transitions in sex roles (e.g. from female-biased care with strong male mating competition to male-biased care with strong female competition) can arise following ecologically induced changes in the costs or benefits of different care types, or in the sex ratio at maturation. Our model provides a clear evolutionary mechanism for sex-role transitions, but also predicts that such transitions should be rare. It consequently contributes towards explaining widespread phylogenetic inertia in parenting and mating systems.
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Affiliation(s)
- Jonathan M Henshaw
- Department of Biological Sciences, University of Idaho, 875 Perimeter MS 3051, Moscow, ID, USA.,Department of Biological and Environmental Science, University of Jyväskylä, PO Box 35, 40014 Finland
| | - Lutz Fromhage
- Department of Biological and Environmental Science, University of Jyväskylä, PO Box 35, 40014 Finland
| | - Adam G Jones
- Department of Biological Sciences, University of Idaho, 875 Perimeter MS 3051, Moscow, ID, USA
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47
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Camp CD, Soelter TM, Wooten JA. Sexual selection and male-biased size dimorphism in a lineage of lungless salamander (Ampibia: Plethodontidae). Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Evolutionary biologists have long focused on the patterns and causes of sexual size dimorphism (SSD). While female-biased SSD is common among ectotherms, a few lineages predominately exhibit male-biased SSD. One example is the clade of desmognathans, a monophyletic group of two genera within the Plethodontinae of the lungless salamander family Plethodontidae. Members of these two genera have a unique pattern of SSD: males mature earlier and at smaller sizes than females but reach greater maximum sizes. We used comparative phylogenetic methods to test whether SSD in these salamanders is the result of sexual selection on males. Spatial evolutionary and ecological vicariance analysis indicated a significant divergence in SSD associated with the phylogenetic origin of the desmognathans. Phylogenetic least-squares regression across the two most speciose genera of the subfamily determined a significant relationship between SSD and adult sex ratio. While male desmognathans are not sexually dimorphic in head size, they have a unique head morphology that causes their heads to grow more rapidly as their body size increases as compared with the heads of other salamanders. This pattern of allometric growth combines with a powerful bite force and enlarged premaxillary teeth to create formidable weaponry that probably is more responsive to sexual selection.
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Affiliation(s)
- Carlos D Camp
- Department of Biology, Piedmont College, Demorest, GA, USA
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Wright E, Galbany J, McFarlin SC, Ndayishimiye E, Stoinski TS, Robbins MM. Male body size, dominance rank and strategic use of aggression in a group-living mammal. Anim Behav 2019. [DOI: 10.1016/j.anbehav.2019.03.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Tompkins EM, Anderson DJ. Sex-specific patterns of senescence in Nazca boobies linked to mating system. J Anim Ecol 2019; 88:986-1000. [PMID: 30746683 DOI: 10.1111/1365-2656.12944] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 10/15/2018] [Indexed: 01/19/2023]
Abstract
Under life-history theories of ageing, increased senescence should follow relatively high reproductive effort. This expectation has rarely been tested against senescence varying between and within the two sexes, although such an approach may clarify the origins of sex-specific ageing in the context of a given mating system. Nazca boobies (Sula granti; a seabird) practise serial monogamy and biparental care. A male-biased population sex ratio results in earlier and more frequent breeding by females. Based on sex-specific reproductive schedules, females were expected to show faster age-related decline for survival and reproduction. Within each sex, high reproductive effort in early life was expected to reduce late-life performance and accelerate senescence. Longitudinal data were used to (a) evaluate the sex specificity of reproductive and actuarial senescence and then (b) test for early-/late-life fitness trade-offs within each sex. Within-sex analyses inform an interpretation of sex differences in senescence based on costs of reproduction. Analyses incorporated individual heterogeneity in breeding performance and cohort-level differences in early-adult environments. Females showed marginally more intense actuarial senescence and stronger age-related declines for fledging success. The opposite pattern (earlier and faster male senescence) was found for breeding probability. Individual reproductive effort in early life positively predicted late-life reproductive performance in both sexes and thus did not support a causal link between early-reproduction/late-life fitness trade-offs and sex differences in ageing. A high-quality diet in early adulthood reduced late-life survival (females) and accelerated senescence for fledging success (males). This study documents clear variation in ageing patterns-by sex, early-adult environment and early-adult reproductive effort-with implications for the role mating systems and early-life environments play in determining ageing patterns. Absent evidence for a disposable soma mechanism, patterns of sex differences in senescence may result from age- and condition-dependent mate choice interacting with this population's male-biased sex ratio and mate rotation.
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Affiliation(s)
- Emily M Tompkins
- Department of Biology, Wake Forest University, Winston-Salem, North Carolina
| | - David J Anderson
- Department of Biology, Wake Forest University, Winston-Salem, North Carolina
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Kramer J, Meunier J. The other facets of family life and their role in the evolution of animal sociality. Biol Rev Camb Philos Soc 2019; 94:199-215. [PMID: 29989333 DOI: 10.1111/brv.12443] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Revised: 06/12/2018] [Accepted: 06/15/2018] [Indexed: 02/06/2023]
Abstract
Family life forms an integral part of the life history of species across the animal kingdom and plays a crucial role in the evolution of animal sociality. Our current understanding of family life, however, is almost exclusively based on studies that (i) focus on parental care and associated family interactions (such as those arising from sibling rivalry and parent-offspring conflict), and (ii) investigate these phenomena in the advanced family systems of mammals, birds, and eusocial insects. Here, we argue that these historical biases have fostered the neglect of key processes shaping social life in ancestral family systems, and thus profoundly hamper our understanding of the (early) evolution of family life. Based on a comprehensive survey of the literature, we first illustrate that the strong focus on parental care in advanced social systems has deflected scrutiny of other important social processes such as sibling cooperation, parent-offspring competition and offspring assistance. We then show that accounting for these neglected processes - and their changing role over time - could profoundly alter our understanding of the origin and subsequent evolution of family life. Finally, we outline how this 'diachronic' perspective on the evolution of family living provides novel insights into general processes driving the evolution of animal sociality. Overall, we infer that the explicit consideration of thus-far neglected facets of family life, together with their study across the whole diversity of family systems, are crucial to advance our understanding of the processes that shape the evolution of social life.
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Affiliation(s)
- Jos Kramer
- Department of Plant and Microbial Biology (IPMB), University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Joël Meunier
- Institut de Recherche sur la Biologie de l'Insecte (IRBI), UMR 726, CNRS, Université de Tours, Avenue Monge, 37200 Tours, France
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