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Dorrestein A, Westcott D, Martin JM, Phalen D, Rose K, Welbergen JA. Bat mating systems-A review and recategorisation. Ecol Evol 2024; 14:e70149. [PMID: 39157663 PMCID: PMC11327276 DOI: 10.1002/ece3.70149] [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: 04/05/2024] [Revised: 07/19/2024] [Accepted: 07/26/2024] [Indexed: 08/20/2024] Open
Abstract
Mating systems, influenced by the social and ecological environment and individual attributes, are fundamental components of animal social organisation, impacting behaviour, animal distribution, ecosystem processes, individual reproductive success, and population dynamics. Bats are of particular interest for studies of mating systems as they are thought to exhibit a greater diversity in mating systems than any other mammalian order, and thus make great models for improving our fundamental understanding of causes and consequences of social organisation. Here, we review the current knowledge of bat mating systems. Our analyses show that research on bat mating systems has not kept pace with research on bats in general and that traditional typologies do not accommodate the mating system of several species. Therefore, we propose an alternative, functional framework to categorise mating systems of bats and by extension of other taxa. We argue that mating systems can be classified according to a male reproductive skew continuum, with an increasing skew from monogamy to true lekking. We include an additional category of lek-like mating system along the continuum to account for previous trans-categorical cases that have the appearance of resource defence but are functionally akin to a lek. The new framework has a total of seven categories: promiscuity, monogamy, female defence polygyny, resource defence polygyny, a lek-like mating system, exploded classical lek, and clustered classical lek. Applying this framework to bats reveals that lek mating systems are more prevalent in bats than previously recognised. It is our aim that this review and the proposed framework provide a greater understanding of bat mating systems particularly and provoke research into the factors that shape mating systems across animal taxa more generally.
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Affiliation(s)
- Annabel Dorrestein
- The Hawkesbury Institute for the EnvironmentWestern Sydney UniversityRichmondNew South WalesAustralia
| | - David Westcott
- Commonwealth Scientific and Industrial Research Organisation, Land and WaterAthertonQueenslandAustralia
| | - John M. Martin
- The Hawkesbury Institute for the EnvironmentWestern Sydney UniversityRichmondNew South WalesAustralia
| | - David Phalen
- Sydney School of Veterinary Science, Faculty of ScienceUniversity of SydneySydneyNew South WalesAustralia
| | - Karrie Rose
- Australian Registry of Wildlife HealthTaronga Conservation Society AustraliaSydneyNew South WalesAustralia
| | - Justin A. Welbergen
- The Hawkesbury Institute for the EnvironmentWestern Sydney UniversityRichmondNew South WalesAustralia
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Wanders K, Chen G, Feng S, Székely T, Urrutia AO. Role-reversed polyandry is associated with faster fast-Z in shorebirds. Proc Biol Sci 2024; 291:20240397. [PMID: 38864333 DOI: 10.1098/rspb.2024.0397] [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: 09/30/2023] [Accepted: 05/14/2024] [Indexed: 06/13/2024] Open
Abstract
In birds, males are homogametic and carry two copies of the Z chromosome ('ZZ'), while females are heterogametic and exhibit a 'ZW' genotype. The Z chromosome evolves at a faster rate than similarly sized autosomes, a phenomenon termed 'fast-Z evolution'. This is thought to be caused by two independent processes-greater Z chromosome genetic drift owing to a reduced effective population size, and stronger Z chromosome positive selection owing to the exposure of partially recessive alleles to selection. Here, we investigate the relative contributions of these processes by considering the effect of role-reversed polyandry on fast-Z in shorebirds, a paraphyletic group of wading birds that exhibit unusually diverse mating systems. We find stronger fast-Z effects under role-reversed polyandry, which is consistent with particularly strong selection on polyandrous females driving the fixation of recessive beneficial alleles. This result contrasts with previous research in birds, which has tended to implicate a primary role of genetic drift in driving fast-Z variation. We suggest that this discrepancy can be interpreted in two ways-stronger sexual selection acting on polyandrous females overwhelms an otherwise central role of genetic drift, and/or sexual antagonism is also contributing significantly to fast-Z and is exacerbated in sexually dimorphic species.
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Affiliation(s)
- Kees Wanders
- Department of Life Sciences, Milner Centre for Evolution, University of Bath , Bath, UK
- Department of Evolutionary Zoology and Human Biology, HUN-REN-DE Reproductive strategies Research Group, University of Debrecen , Debrecen, Hungary
- Natural History Museum of Denmark, University of Copenhagen , Copenhagen, Denmark
| | - Guangji Chen
- Center for Evolutionary & Organismal Biology, Liangzhu Laboratory, Department of General Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine , Hangzhou, People's Republic of China
- BGI Research , Wuhan, People's Republic of China
- College of Life Sciences, University of Chinese Academy of Sciences , Beijing, People's Republic of China
| | - Shaohong Feng
- Center for Evolutionary & Organismal Biology, Liangzhu Laboratory, Department of General Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine , Hangzhou, People's Republic of China
| | - Tamás Székely
- Department of Life Sciences, Milner Centre for Evolution, University of Bath , Bath, UK
- Department of Evolutionary Zoology and Human Biology, HUN-REN-DE Reproductive strategies Research Group, University of Debrecen , Debrecen, Hungary
- Debrecen Biodiversity Centre, University of Debrecen , Debrecen, Hungary
| | - Arraxi O Urrutia
- Department of Life Sciences, Milner Centre for Evolution, University of Bath , Bath, UK
- Instituto de Ecologia, UNAM , Mexico City, Mexico
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Pappert FA, Dubin A, Torres GG, Roth O. Navigating sex and sex roles: deciphering sex-biased gene expression in a species with sex-role reversal ( Syngnathus typhle). ROYAL SOCIETY OPEN SCIENCE 2024; 11:rsos.231620. [PMID: 38577217 PMCID: PMC10987989 DOI: 10.1098/rsos.231620] [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: 10/25/2023] [Revised: 02/02/2024] [Accepted: 03/11/2024] [Indexed: 04/06/2024]
Abstract
Sexual dimorphism, the divergence in morphological traits between males and females of the same species, is often accompanied by sex-biased gene expression. However, the majority of research has focused on species with conventional sex roles, where females have the highest energy burden with both egg production and parental care, neglecting the diversity of reproductive roles found in nature. We investigated sex-biased gene expression in Syngnathus typhle, a sex-role reversed species with male pregnancy, allowing us to separate two female traits: egg production and parental care. Using RNA sequencing, we examined gene expression across organs (brain, head kidney and gonads) at various life stages, encompassing differences in age, sex and reproductive status. While some gene groups were more strongly associated with sex roles, such as stress resistance and immune defence, others were driven by biological sex, such as energy and lipid storage regulation in an organ- and age-specific manner. By investigating how genes regulate and are regulated by changing reproductive roles and resource allocation in a model system with an unconventional life-history strategy, we aim to better understand the importance of sex and sex role in regulating gene expression patterns, broadening the scope of this discussion to encompass a wide range of organisms.
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Affiliation(s)
- Freya A. Pappert
- Marine Evolutionary Biology, Zoological Institute, Christian-Albrechts-Universität Kiel, Kiel24118, Germany
- Evolutionary Ecology of Marine Fishes, Helmholtz-Centre for Ocean Research Kiel (GEOMAR), Kiel24105, Germany
| | - Arseny Dubin
- Marine Evolutionary Biology, Zoological Institute, Christian-Albrechts-Universität Kiel, Kiel24118, Germany
| | - Guillermo G. Torres
- Institute of Clinical Molecular Biology (IKMB), University Hospital Schleswig-Holstein, Kiel University, Kiel24105, Germany
| | - Olivia Roth
- Marine Evolutionary Biology, Zoological Institute, Christian-Albrechts-Universität Kiel, Kiel24118, Germany
- Evolutionary Ecology of Marine Fishes, Helmholtz-Centre for Ocean Research Kiel (GEOMAR), Kiel24105, Germany
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4
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Wang D, Zhang W, Yang S, Richter XYL. Sex differences in avian parental care patterns vary across the breeding cycle. Nat Commun 2023; 14:6980. [PMID: 37914691 PMCID: PMC10620184 DOI: 10.1038/s41467-023-42767-5] [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: 11/04/2022] [Accepted: 10/20/2023] [Indexed: 11/03/2023] Open
Abstract
Parental care in birds consists of elaborate forms across stages, including nest building, incubation, and offspring provision. Despite their evolutionary importance, knowledge gaps exist in the extent to which parents contribute disproportionately to these forms and factors that are associated with variations in care patterns between sexes. Here, we analyzed 1533 bird species and discovered remarkable variability in care patterns. We show that parental care should not be viewed as a unitary trait but rather as a set of integrated features that exhibit considerable temporal and sex-specific variation. Our analyses also reveal moderate consistency in care patterns between breeding stages, pointing towards shared intrinsic factors driving sex-specific care. Notably, we found that species experiencing strong sexual selection on males or species facing paternity uncertainty display a tendency towards female-biased care. This work advances our understanding of the temporal variations in sex-specific contributions to avian parental care and their potential evolutionary drivers.
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Affiliation(s)
- Daiping Wang
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang, 100101, Beijing, China.
- University of Chinese Academy of Sciences, 100049, Beijing, China.
| | - Wenyuan Zhang
- Edward Grey Institute, Department of Biology, University of Oxford, Oxford, OX1 3SZ, UK
- Department of Biology, Quebec Centre for Biodiversity Science, McGill University, Montreal, QC, H3A 1B1, Canada
| | - Shuai Yang
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang, 100101, Beijing, China
- University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Xiang-Yi Li Richter
- Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, CH-3012, Bern, Switzerland.
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McLaughlin JF, Brock KM, Gates I, Pethkar A, Piattoni M, Rossi A, Lipshutz SE. Multivariate Models of Animal Sex: Breaking Binaries Leads to a Better Understanding of Ecology and Evolution. Integr Comp Biol 2023; 63:891-906. [PMID: 37156506 PMCID: PMC10563656 DOI: 10.1093/icb/icad027] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 04/28/2023] [Accepted: 05/05/2023] [Indexed: 05/10/2023] Open
Abstract
"Sex" is often used to describe a suite of phenotypic and genotypic traits of an organism related to reproduction. However, these traits-gamete type, chromosomal inheritance, physiology, morphology, behavior, etc.-are not necessarily coupled, and the rhetorical collapse of variation into a single term elides much of the complexity inherent in sexual phenotypes. We argue that consideration of "sex" as a constructed category operating at multiple biological levels opens up new avenues for inquiry in our study of biological variation. We apply this framework to three case studies that illustrate the diversity of sex variation, from decoupling sexual phenotypes to the evolutionary and ecological consequences of intrasexual polymorphisms. We argue that instead of assuming binary sex in these systems, some may be better categorized as multivariate and nonbinary. Finally, we conduct a meta-analysis of terms used to describe diversity in sexual phenotypes in the scientific literature to highlight how a multivariate model of sex can clarify, rather than cloud, studies of sexual diversity within and across species. We argue that such an expanded framework of "sex" better equips us to understand evolutionary processes, and that as biologists, it is incumbent upon us to push back against misunderstandings of the biology of sexual phenotypes that enact harm on marginalized communities.
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Affiliation(s)
- J F McLaughlin
- Department of Environmental Science, Policy, and Management, College of Natural Resources, University of California, Berkeley, CA 94720, USA
| | - Kinsey M Brock
- Department of Environmental Science, Policy, and Management, College of Natural Resources, University of California, Berkeley, CA 94720, USA
- Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
- Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | - Isabella Gates
- Department of Biology, Loyola University Chicago, Chicago, IL 60660, USA
| | - Anisha Pethkar
- Department of Biology, Loyola University Chicago, Chicago, IL 60660, USA
| | - Marcus Piattoni
- Department of Biology, Loyola University Chicago, Chicago, IL 60660, USA
| | - Alexis Rossi
- Department of Biology, Loyola University Chicago, Chicago, IL 60660, USA
| | - Sara E Lipshutz
- Department of Biology, Loyola University Chicago, Chicago, IL 60660, USA
- Department of Biology, Duke University, Durham, NC 27708, USA
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6
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Anderson AP, Falk JJ. Cross-sexual Transfer Revisited. Integr Comp Biol 2023; 63:936-945. [PMID: 37147027 DOI: 10.1093/icb/icad021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 04/24/2023] [Accepted: 05/01/2023] [Indexed: 05/07/2023] Open
Abstract
In her influential book "Developmental Plasticity and Evolution," Mary Jane West-Eberhard introduced the concept of cross-sexual transfer, where traits expressed in one sex in an ancestral species become expressed in the other sex. Despite its potential ubiquity, we find that cross-sexual transfer has been under-studied and under-cited in the literature, with only a few experimental papers that have invoked the concept. Here, we aim to reintroduce cross-sexual transfer as a powerful framework for explaining sex variation and highlight its relevance in current studies on the evolution of sexual heteromorphism (different means or modes in trait values between the sexes). We discuss several exemplary studies of cross-sexual transfer that have been published in the past two decades, further building on West-Eberhard's extensive review. We emphasize two scenarios as potential avenues of study, within-sex polymorphic and sex-role reversed species, and discuss the evolutionary and adaptive implications. Lastly, we propose future questions to expand our understanding of cross-sexual transfer, from nonhormonal mechanisms to the identification of broad taxonomic patterns. As evolutionary biologists increasingly recognize the nonbinary and often continuous nature of sexual heteromorphism, the cross-sexual framework has important utility for generating novel insights and perspectives on the evolution of sexual phenotypes across diverse taxa.
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Affiliation(s)
| | - Jay Jinsing Falk
- Department of Biology, University of Washington, Seattle, WA 98195, USA
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, CO 80309, USA
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Anderson AP, Renn SCP. The Ancestral Modulation Hypothesis: Predicting Mechanistic Control of Sexually Heteromorphic Traits Using Evolutionary History. Am Nat 2023; 202:241-259. [PMID: 37606950 DOI: 10.1086/725438] [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] [Indexed: 08/23/2023]
Abstract
AbstractAcross the animal kingdom there are myriad forms within a sex across, and even within, species, rendering concepts of universal sex traits moot. The mechanisms that regulate the development of these trait differences are varied, although in vertebrates, common pathways involve gonadal steroid hormones. Gonadal steroids are often associated with heteromorphic trait development, where the steroid found at higher circulating levels is the one involved in trait development for that sex. Occasionally, there are situations in which a gonadal steroid associated with heteromorphic trait development in one sex is involved in heteromorphic or monomorphic trait development in another sex. We propose a verbal hypothesis, the ancestral modulation hypothesis (AMH), that uses the evolutionary history of the trait-particularly which sex ancestrally possessed higher trait values-to predict the regulatory pathway that governs trait expression. The AMH predicts that the genomic architecture appears first to resolve sexual conflict in an initially monomorphic trait. This architecture takes advantage of existing sex-biased signals, the gonadal steroid pathway, to generate trait heteromorphism. In cases where the other sex experiences evolutionary pressure for the new phenotype, that sex will co-opt the existing architecture by altering its signal to match that of the original high-trait-value sex. We describe the integrated levels needed to produce this pattern and what the expected outcomes will be given the evolutionary history of the trait. We present this framework as a testable hypothesis for the scientific community to investigate and to create further engagement and analysis of both ultimate and proximate approaches to sexual heteromorphism.
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McLaughlin JF, Aguilar C, Bernstein JM, Navia-Gine WG, Cueto-Aparicio LE, Alarcon AC, Alarcon BD, Collier R, Takyar A, Vong SJ, López-Chong OG, Driver R, Loaiza JR, De León LF, Saltonstall K, Lipshutz SE, Arcila D, Brock KM, Miller MJ. Comparative phylogeography reveals widespread cryptic diversity driven by ecology in Panamanian birds. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023. [PMID: 36993716 DOI: 10.1101/2023.01.26.525769] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
UNLABELLED Widespread species often harbor unrecognized genetic diversity, and investigating the factors associated with such cryptic variation can help us better understand the forces driving diversification. Here, we identify potential cryptic species based on a comprehensive dataset of COI mitochondrial DNA barcodes from 2,333 individual Panamanian birds across 429 species, representing 391 (59%) of the 659 resident landbird species of the country, as well as opportunistically sampled waterbirds. We complement this dataset with additional publicly available mitochondrial loci, such as ND2 and cytochrome b, obtained from whole mitochondrial genomes from 20 taxa. Using barcode identification numbers (BINs), we find putative cryptic species in 19% of landbird species, highlighting hidden diversity in the relatively well-described avifauna of Panama. Whereas some of these mitochondrial divergence events corresponded with recognized geographic features that likely isolated populations, such as the Cordillera Central highlands, the majority (74%) of lowland splits were between eastern and western populations. The timing of these splits are not temporally coincident across taxa, suggesting that historical events, such as the formation of the Isthmus of Panama and Pleistocene climatic cycles, were not the primary drivers of cryptic diversification. Rather, we observed that forest species, understory species, insectivores, and strongly territorial species-all traits associated with lower dispersal ability-were all more likely to have multiple BINs in Panama, suggesting strong ecological associations with cryptic divergence. Additionally, hand-wing index, a proxy for dispersal capability, was significantly lower in species with multiple BINs, indicating that dispersal ability plays an important role in generating diversity in Neotropical birds. Together, these results underscore the need for evolutionary studies of tropical bird communities to consider ecological factors along with geographic explanations, and that even in areas with well-known avifauna, avian diversity may be substantially underestimated. LAY SUMMARY - What factors are common among bird species with cryptic diversity in Panama? What role do geography, ecology, phylogeographic history, and other factors play in generating bird diversity?- 19% of widely-sampled bird species form two or more distinct DNA barcode clades, suggesting widespread unrecognized diversity.- Traits associated with reduced dispersal ability, such as use of forest understory, high territoriality, low hand-wing index, and insectivory, were more common in taxa with cryptic diversity. Filogeografía comparada revela amplia diversidad críptica causada por la ecología en las aves de Panamá. RESUMEN Especies extendidas frecuentemente tiene diversidad genética no reconocida, y investigando los factores asociados con esta variación críptica puede ayudarnos a entender las fuerzas que impulsan la diversificación. Aquí, identificamos especies crípticas potenciales basadas en un conjunto de datos de códigos de barras de ADN mitocondrial de 2,333 individuos de aves de Panama en 429 especies, representando 391 (59%) de las 659 especies de aves terrestres residentes del país, además de algunas aves acuáticas muestreada de manera oportunista. Adicionalmente, complementamos estos datos con secuencias mitocondriales disponibles públicamente de otros loci, tal como ND2 o citocroma b, obtenidos de los genomas mitocondriales completos de 20 taxones. Utilizando los números de identificación de código de barras (en ingles: BINs), un sistema taxonómico numérico que proporcina una estimación imparcial de la diversidad potencial a nivel de especie, encontramos especies crípticas putativas en 19% de las especies de aves terrestres, lo que destaca la diversidad oculta en la avifauna bien descrita de Panamá. Aunque algunos de estos eventos de divergencia conciden con características geográficas que probablemente aislaron las poblaciones, la mayoría (74%) de la divergencia en las tierras bajas se encuentra entre las poblaciones orientales y occidentales. El tiempo de esta divergencia no coincidió entre los taxones, sugiriendo que eventos históricos tales como la formación del Istmo de Panamá y los ciclos climáticos del pleistoceno, no fueron los principales impulsores de la especiación. En cambio, observamos asociaciones fuertes entre las características ecológicas y la divergencia mitocondriale: las especies del bosque, sotobosque, con una dieta insectívora, y con territorialidad fuerte mostraton múltiple BINs probables. Adicionalmente, el índice mano-ala, que está asociado a la capacidad de dispersión, fue significativamente menor en las especies con BINs multiples, sugiriendo que la capacidad de dispersión tiene un rol importamente en la generación de la diversidad de las aves neotropicales. Estos resultos demonstran la necesidad de que estudios evolutivos de las comunidades de aves tropicales consideren los factores ecológicos en conjunto con las explicaciones geográficos. Palabras clave: biodiversidad tropical, biogeografía, códigos de barras, dispersión, especies crípticas.
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Fracasso G, Heylen D, Matthysen E. Male mating preference in an ixodid tick. Parasit Vectors 2022; 15:316. [PMID: 36071436 PMCID: PMC9450281 DOI: 10.1186/s13071-022-05419-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 07/27/2022] [Indexed: 11/15/2022] Open
Abstract
Background Mate choice is a fundamental element of sexual selection and has the potential to shape the evolution of traits. Mate choice based on body size has been shown to be a common trait in several arthropod species. In hard ticks, a taxon of medical and veterinary importance, engorgement weight is positively correlated with reproductive output but it is unknown whether adult males show mate choice. Here, we experimentally investigated whether males (i) use chemical cues to choose their mating partner, (ii) consistently choose for the same female individual and (iii) prefer females with highest weight after feeding. Methods We used two experimental setups which allowed chemical communication between ticks: (i) a horizontal tube preventing physical contact with the female and (ii) an arena where tactile cues were allowed. In total, we tested 62 different triads in 124 tests (66 tests in the horizontal tube and 58 in the arena) composed of one male that could choose between two engorged females. Specifically, we tested 42 triads in the tube and 46 in the arena; 24 triads were repeatedly tested in the tube while 38 triads were tested in both setups. Results We found no preference for individual or heavier females in either setup. However, in the horizontal tube setup, males significantly preferred females that were not visited by them in the previous test. Conclusions Our results suggest a lack of male mate choice despite heavier females having higher fecundity. However, future studies should take into account that males may recognize the potential mating partners they previously met. Graphical Abstract ![]()
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Affiliation(s)
- Gerardo Fracasso
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, 2610, Wilrijk, Belgium. .,Eco-Epidemiology Group, Department of Biomedical Sciences, Institute of Tropical Medicine, 2000, Antwerp, Belgium.
| | - Dieter Heylen
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, 2610, Wilrijk, Belgium.,Eco-Epidemiology Group, Department of Biomedical Sciences, Institute of Tropical Medicine, 2000, Antwerp, Belgium.,Interuniversity Institute for Biostatistics and Statistical Bioinformatics, Hasselt University, 3590, Diepenbeek, Belgium
| | - Erik Matthysen
- Evolutionary Ecology Group, Department of Biology, University of Antwerp, 2610, Wilrijk, Belgium
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Daly M, Perry G. Sexual Selection and the Treatment of Predecessors' Progeny by Replacement Mates. Front Psychol 2022; 13:924238. [PMID: 35769745 PMCID: PMC9234565 DOI: 10.3389/fpsyg.2022.924238] [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: 04/20/2022] [Accepted: 05/24/2022] [Indexed: 11/23/2022] Open
Abstract
Darwin's theory of sexual selection provides a useful framework for understanding the behavior of stepparents. A non-human animal whose new mate has dependent young may kill, ignore, or adopt the predecessor's progeny. The third option has been interpreted as courtship ("mating effort"), and whether selection favors such investment over killing or ignoring the young apparently depends on aspects of the species-typical ecology and demography. The tripartite categorization of responses is a simplification, however, There is variability both within and between species along a continuum from rejection to "full adoption." The average stepparent invests less than the average birth parent, but more than nothing. Human stepparents have often been found to kill young children at higher rates than birth parents, but stepparental infanticide cannot plausibly be interpreted as a human adaptation, both because it is extremely rare and because it is almost certainly more likely to reduce the killer's fitness than to raise it. How sexual selection theory remains relevant to human stepparenting is by suggesting testable hypotheses about predictors of the variability in stepparental investment.
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Affiliation(s)
- Martin Daly
- Department of Psychology, Neuroscience & Behavior, McMaster University, Hamilton, ON, Canada
| | - Gretchen Perry
- Department of Sociology, Anthropology & Human Services, University of Canterbury, Christchurch, New Zealand
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11
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Benefits of paternal thermoregulation: male midwife toads select warmer temperature to shorten embryonic development. Behav Ecol Sociobiol 2022. [DOI: 10.1007/s00265-022-03155-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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12
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Grebe NM, Sheikh A, Drea CM. Integrating the female masculinization and challenge hypotheses: Female dominance, male deference, and seasonal hormone fluctuations in adult blue-eyed black lemurs (Eulemur flavifrons). Horm Behav 2022; 139:105108. [PMID: 35033896 DOI: 10.1016/j.yhbeh.2022.105108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 12/22/2021] [Accepted: 01/03/2022] [Indexed: 11/19/2022]
Abstract
In the decades since female social dominance was first described in strepsirrhine primates, researchers have sought to uncover the proximate and ultimate explanations for its development. In the females of various female-dominant species, androgens have been implicated as regulators of behavior and/or predictors of seasonal fluctuations in aggression (the 'Female Masculinization Hypothesis'). Males, more generally, respond to changing social demands via seasonal fluctuations in androgen-mediated behavior (the 'Challenge Hypothesis'), that may also entail changes in activation of the hypothalamic-pituitary-adrenal axis. Here, we explore if androgens, glucocorticoids, and intersexual behavior fluctuate seasonally in the female-dominant, blue-eyed black lemur (Eulemur flavifrons), with potential consequences for understanding female aggression and male deference. Across two studies conducted during the breeding and nonbreeding seasons, we assessed rates of mixed-sex, dyadic social behavior (aggression and affiliation) and concentrations of fecal glucocorticoid metabolites (Study 1) and serum sex hormones (androstenedione, testosterone, and estradiol; Study 2). Our results align with several predictions inspired by the Female Masculinization and Challenge Hypotheses for intersexual relations: During the breeding season, specifically, both aggression and androstenedione peaked in females, while female-initiated affiliation decreased, potentially to facilitate female resource access and reproductive control. By comparison, all target hormones (androgens, estrogen, and glucocorticoids) peaked in males, with glucocorticoid concentrations potentially increasing in response to the surge in female aggression, and unusually high estrogen concentrations year-round potentially facilitating male deference via male-initiated affiliation. These results suggest complex, seasonally and hormonally mediated behavior in Eulemur flavifrons.
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Affiliation(s)
- Nicholas M Grebe
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, United States of America.
| | - Alizeh Sheikh
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, United States of America
| | - Christine M Drea
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, United States of America; Department of Biology, Duke University, Durham, NC 27708, United States of America
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13
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Zhang H, Liu Y, Qin G, Lin Q. Identification of neurohypophysial hormones and the role of VT in the parturition of pregnant seahorses ( Hippocampus erectus). Front Endocrinol (Lausanne) 2022; 13:923234. [PMID: 35966100 PMCID: PMC9372264 DOI: 10.3389/fendo.2022.923234] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 07/06/2022] [Indexed: 11/26/2022] Open
Abstract
Neurohypophysial hormones regulate the reproductive behavior of teleosts; however, their role in the gestation and parturition of ovoviviparous fishes with male pregnancy (syngnathids) remains to be demonstrated. In the present study, the complementary DNA (cDNA) sequences of arginine vasotocin (VT) and isotocin (IT) from the lined seahorse (Hippocampus erectus) were cloned and identified. We observed that the mature core peptides of seahorse VT and IT were conserved among teleosts. In the phylogenic tree, seahorse VT and IT were clustered independently with teleost VT and IT. The tissue distribution patterns of VT and IT were similar, and both were highly expressed in the brain, gills, and gonads. Interestingly, they were also expressed to some extent in the brood pouch. In situ hybridization revealed that VT and IT messenger RNA (mRNA) signals in the brain were mainly located in the preoptic area region of the hypothalamus. Intraperitoneal administration of the VT core peptide to pregnant seahorses induced premature parturition, stimulated gonadotropin release, increased serum estrogen levels, and decreased prolactin secretion. Moreover, VT injection upregulated the mRNA expression of the membrane estrogen receptor in the brood pouch. In summary, neurohypophysial hormones promote premature parturition by regulating estrogen synthesis through the hypothalamus-pituitary-gonad axis.
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Affiliation(s)
- Huixian Zhang
- Chinese Academy of Science (CAS) Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yali Liu
- Chinese Academy of Science (CAS) Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Geng Qin
- Chinese Academy of Science (CAS) Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Qiang Lin
- Chinese Academy of Science (CAS) Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
- *Correspondence: Qiang Lin,
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14
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Differences in plumage coloration predict female but not male territorial responses in three antbird sister species pairs. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2021.09.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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15
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Leese JM, Blatt T. Sex Differences in How Territory Quality Affects Aggression in Convict Cichlids. Integr Org Biol 2021; 3:obab028. [PMID: 34671717 PMCID: PMC8522484 DOI: 10.1093/iob/obab028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 08/23/2021] [Accepted: 09/28/2021] [Indexed: 01/22/2023] Open
Abstract
In animal contests, the value an individual assigns to limited resources can directly impact the level of aggression it demonstrates. For territorial species, individuals often assess their territory quality and appropriately modify the time and energy invested in its defense. In this study, male and female convict cichlids, Amatitlania nigrofasciata, were acclimated to one of three territorial treatments representing either a low, medium, or high resource value. Territories with a “Low Value” included substrate alone, “Medium Value” territories included substrate and a nest site, and a “High Value” territory included substrate, a nest site, and constant food source. After three days of acclimation, a size-matched intruder was introduced to elicit territorial aggression and behaviors were observed. Territory quality affected one measure of low-intensity aggression (displays) in residents but had no effect on high-intensity aggression (bites and chases). Moreover, there was a significant effect of sex, with males and females differing in the types of aggressive behaviors demonstrated across all treatments. Females showed more low-intensity aggressive behaviors toward intruders than males did. Additionally, a significant interaction of sex and territory quality was observed on two measures of high-intensity aggressive behavior (bites and chases), with females more likely than males to increase aggressive behaviors along with increasing territory quality. This suggests that females may be more sensitive and/or responsive to changes in the quality of a territory, possibly due to the necessity of a suitable nest site for egg deposition within a territory.
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Affiliation(s)
- Joseph M Leese
- Department of Biology, DeSales University, 2755 Station Avenue, Center Valley, PA 18034, USA
| | - T Blatt
- Department of Biology, DeSales University, 2755 Station Avenue, Center Valley, PA 18034, USA
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16
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Fritzsche K, Henshaw JM, Johnson BD, Jones AG. The 150th anniversary of The Descent of Man: Darwin and the impact of sex-role reversal on sexual selection research. Biol J Linn Soc Lond 2021. [DOI: 10.1093/biolinnean/blab091] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
The year 2021 marks the 150th anniversary of the publication of Charles Darwin’s extraordinary book The Descent of Man and Selection in Relation to Sex. Here, we review the history and impact of a single profound insight from The Descent of Man: that, in some few species, females rather than males compete for access to mates. In other words, these species are ‘sex-role reversed’ with respect to mating competition and sexual selection compared to the majority of species in which sexual selection acts most strongly on males. Over the subsequent 150 years, sex-role-reversed species have motivated multiple key conceptual breakthroughs in sexual selection. The surprising mating dynamics of such species challenged scientists’ preconceptions, forcing them to examine implicit assumptions and stereotypes. This wider worldview has led to a richer and more nuanced understanding of animal mating systems and, in particular, to a proper appreciation for the fundamental role that females play in shaping these systems. Sex-role-reversed species have considerable untapped potential and will continue to contribute to sexual selection research in the decades to come.
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Affiliation(s)
- Karoline Fritzsche
- Institute of Biology I, University of Freiburg, Hauptstraße 1, D-79104 Freiburg, Germany
| | - Jonathan M Henshaw
- Institute of Biology I, University of Freiburg, Hauptstraße 1, D-79104 Freiburg, Germany
| | | | - Adam G Jones
- Department of Biological Sciences, University of Idaho, Moscow, ID, USA
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17
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The More Fertile, the More Creative: Changes in Women's Creative Potential across the Ovulatory Cycle. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18105390. [PMID: 34070114 PMCID: PMC8158362 DOI: 10.3390/ijerph18105390] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/08/2021] [Accepted: 05/15/2021] [Indexed: 11/30/2022]
Abstract
Creative thinking is a defining human feature. It provides novel solutions and as such undoubtedly has contributed to our survival. However, according to signaling theory, creativity could also have evolved through sexual selection as a potential fitness indicator. In our study, we tested one implication of this theory. Specifically, we hypothesized that if creativity can serve as a signal of women’s fitness, then we should observe an increase in creative thinking in the fertile phase of the ovulatory cycle compared to other non-fertile phases. In our study (N = 751), we tested creative potential throughout the ovulatory cycle. We found a positive correlation between the probability of conception and both creative originality and flexibility. Importantly, we also tested the mediating role of arousal in the relationship between the probability of conception and creative thinking. The results of our study are discussed in terms of signaling theory, through which women advertise their fitness with their creativity.
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18
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Lange L, Bégué L, Brischoux F, Lourdais O. The costs of being a good dad: egg-carrying and clutch size impair locomotor performance in male midwife toads (Alytes obstetricans). Biol J Linn Soc Lond 2020. [DOI: 10.1093/biolinnean/blaa185] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
Parental care is widespread across the animal kingdom. Parental behaviours are beneficial by increasing offspring survival but induce significant costs to the parents. Because parental care is far more common in females, the associated reproductive costs have been largely studied in this sex. Although male parental care is likely to involve significant costs, it has been markedly less well investigated. We studied the costs of egg-carrying on locomotor performance in an amphibian species (Alytes obstetricans) with male parental care. We examined complementary parameters including hopping performance, righting response, hindleg muscle response to egg burden, and homing time in males carrying or not carrying eggs. We found that carrying males showed altered locomotor performance for most traits. In addition, alteration of performance was closely related to relative clutch size. Clutch desertion occurred in smaller individuals carrying larger relative clutch mass, and performance after desertion was similar to that of non-reproductive individuals. Overall, our study demonstrates that carrying eggs significantly alters male mobility and that performance–clutch size trade-offs are relevant in understanding the evolution of paternal care.
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Affiliation(s)
- Léa Lange
- Centre d’Études Biologiques de Chizé, CNRS et Université de la Rochelle – UMR 7372, Villiers en Bois, France
| | - Lauriane Bégué
- Centre d’Études Biologiques de Chizé, CNRS et Université de la Rochelle – UMR 7372, Villiers en Bois, France
| | - François Brischoux
- Centre d’Études Biologiques de Chizé, CNRS et Université de la Rochelle – UMR 7372, Villiers en Bois, France
| | - Olivier Lourdais
- Centre d’Études Biologiques de Chizé, CNRS et Université de la Rochelle – UMR 7372, Villiers en Bois, France
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
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19
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Rosvall KA, Bentz AB, George EM. How research on female vertebrates contributes to an expanded challenge hypothesis. Horm Behav 2020; 123:104565. [PMID: 31419407 PMCID: PMC7061077 DOI: 10.1016/j.yhbeh.2019.104565] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 08/08/2019] [Accepted: 08/09/2019] [Indexed: 12/21/2022]
Abstract
The bi-directional links between hormones and behavior have been a rich area of research for decades. Theory on the evolution of testosterone (T) was greatly advanced by the challenge hypothesis, which presented a framework for understanding interspecific, seasonal, and social variation in T levels in males, and how they are shaped by the competing demands of parental care and male-male competition. Female competition is also widespread in nature, although it is less clear whether or how the challenge hypothesis applies to females. Here, we evaluate this issue in four parts: (1) We summarize and update prior analyses of seasonal plasticity and interspecific variation in T in females. (2) We evaluate experimental links between T and female aggression on shorter timescales, asking how T manipulations affect aggression and conversely, how social manipulations affect T levels in female mammals, birds, lizards, and fishes. (3) We examine alternative mechanisms that may link aggression to the social environment independently of T levels in circulation. (4) We present a case study, including new data analyses, in an aggressive female bird (the tree swallow, Tachycineta bicolor) to explore how variation in tissue-level processing of T may bridge the gap between circulating T and variation in behavior that is visible to natural selection. We close by connecting these multivariate levels of sex steroid signaling systems alongside different temporal scales (social, seasonal, and evolutionary) to generate broadly applicable insights into how animals respond to their social environment, regardless of whether they are male or female.
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Affiliation(s)
- Kimberly A Rosvall
- Department of Biology, Indiana University, Bloomington, IN 47405, USA; Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA.
| | - Alexandra B Bentz
- Department of Biology, Indiana University, Bloomington, IN 47405, USA; Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA
| | - Elizabeth M George
- Department of Biology, Indiana University, Bloomington, IN 47405, USA; Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA
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20
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Lipshutz SE, Rosvall KA. Testosterone secretion varies in a sex- and stage-specific manner: Insights on the regulation of competitive traits from a sex-role reversed species. Gen Comp Endocrinol 2020; 292:113444. [PMID: 32092297 DOI: 10.1016/j.ygcen.2020.113444] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 02/14/2020] [Accepted: 02/20/2020] [Indexed: 12/14/2022]
Abstract
Testosterone (T) mediates a variety of traits that function in competition for mates, including territorial aggression, ornaments, armaments, and gametogenesis. The link between T and mating competition has been studied mainly in males, but females also face selection pressures to compete for mates. Sex-role reversed species, in which females are the more competitive sex, provide a unique perspective on the role of T in promoting competitive traits. Here, we examine patterns of T secretion in sex-role reversed northern jacanas (Jacana spinosa) during breeding, when females are fertile and males are either seeking copulations or conducting parental care. We measured baseline levels of T in circulation along with a suite of behavioral and morphological traits putatively involved in mating competition. We evaluated hypotheses that levels of T track gonadal sex and parental role, and we begin to investigate whether T and competitive traits co-vary in a sex- and stage- specific manner. Although females had higher expression of competitive traits than males at either breeding stage, we found that females and incubating males had similar levels of T secretion, which were lower than those observed in copulating males. T was correlated with wing spur length in females and testes mass in copulating males, but was otherwise uncorrelated with other competitive traits. These findings suggest that levels of T in circulation alone do not predict variation in competitive traits across levels of analysis, including gonadal sex and parental role. Instead, our findings coupled with prior research indicate that selection for female mating competition and male care may generate different physiological regulation of competitive traits.
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Affiliation(s)
- Sara E Lipshutz
- Department of Biology, Indiana University, Bloomington, IN 47405, USA; Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN 37996, USA.
| | - Kimberly A Rosvall
- Department of Biology, Indiana University, Bloomington, IN 47405, USA; Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA
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21
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Abstract
Synopsis
Females of some species are considered sex-role reversed, meaning that they face stronger competition for mates compared to males. While much attention has been paid to behavioral and morphological patterns associated with sex-role reversal, less is known about its physiological regulation. Here, we evaluate hypotheses relating to the neuroendocrine basis of sex-role reversal. We refute the most widely tested activational hypothesis for sex differences in androgen secretion; sex-role reversed females do not have higher levels of androgens in circulation than males. However, we find some evidence that the effects of androgens may be sex-specific; circulating androgen levels correlate with some competitive phenotypes in sex-role reversed females. We also review evidence that sex-role reversed females have higher tissue-specific sensitivity to androgens than males, at least in some species and tissues. Organizational effects may explain these relationships, considering that early exposure to sex steroids can shape later sensitivity to hormones, often in sex-specific ways. Moving forward, experimental and correlative studies on the ontogeny and expression of sex-role reversal will further clarify the mechanisms that generate sex-specific behaviors and sex roles.
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Affiliation(s)
- Sara E Lipshutz
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Kimberly A Rosvall
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
- Center for the Integrated Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA
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22
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Anderson AP, Rose E, Flanagan SP, Jones AG. The Estrogen-Responsive Transcriptome of Female Secondary Sexual Traits in the Gulf Pipefish. J Hered 2020; 111:294-306. [PMID: 32124926 DOI: 10.1093/jhered/esaa008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 02/24/2020] [Indexed: 01/01/2023] Open
Abstract
Sexual dimorphism often results from hormonally regulated trait differences between the sexes. In sex-role-reversed vertebrates, females often have ornaments used in mating competition that are expected to be under hormonal control. Males of the sex-role-reversed Gulf pipefish (Syngnathus scovelli) develop female-typical traits when they are exposed to estrogens. We aimed to identify genes whose expression levels changed during the development and maintenance of female-specific ornaments. We performed RNA-sequencing on skin and muscle tissue in male Gulf pipefish with and without exposure to estrogen to investigate the transcriptome of the sexually dimorphic ornament of vertical iridescent bands found in females and estrogen-exposed males. We further compared differential gene expression patterns between males and females to generate a list of genes putatively involved in the female secondary sex traits of bands and body depth. A detailed analysis of estrogen-receptor binding sites demonstrates that estrogen-regulated genes tend to have nearby cis-regulatory elements. Our results identified a number of genes that differed between the sexes and confirmed that many of these were estrogen-responsive. These estrogen-regulated genes may be involved in the arrangement of chromatophores for color patterning, as well as in the growth of muscles to achieve the greater body depth typical of females in this species. In addition, anaerobic respiration and adipose tissue could be involved in the rigors of female courtship and mating competition. Overall, this study generates a number of interesting hypotheses regarding the genetic basis of a female ornament in a sex-role-reversed pipefish.
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Affiliation(s)
| | - Emily Rose
- Department of Biology, University of Tampa, Tampa, FL
| | - Sarah P Flanagan
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Adam G Jones
- Department of Biological Sciences, University of Idaho, Moscow, ID
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23
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Portik DM, Bell RC, Blackburn DC, Bauer AM, Barratt CD, Branch WR, Burger M, Channing A, Colston TJ, Conradie W, Dehling JM, Drewes RC, Ernst R, Greenbaum E, Gvoždík V, Harvey J, Hillers A, Hirschfeld M, Jongsma GFM, Kielgast J, Kouete MT, Lawson LP, Leaché AD, Loader SP, Lötters S, Meijden AVD, Menegon M, Müller S, Nagy ZT, Ofori-Boateng C, Ohler A, Papenfuss TJ, Rößler D, Sinsch U, Rödel MO, Veith M, Vindum J, Zassi-Boulou AG, McGuire JA. Sexual Dichromatism Drives Diversification within a Major Radiation of African Amphibians. Syst Biol 2020; 68:859-875. [PMID: 31140573 DOI: 10.1093/sysbio/syz023] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 02/15/2019] [Accepted: 04/09/2019] [Indexed: 01/11/2023] Open
Abstract
Theory predicts that sexually dimorphic traits under strong sexual selection, particularly those involved with intersexual signaling, can accelerate speciation and produce bursts of diversification. Sexual dichromatism (sexual dimorphism in color) is widely used as a proxy for sexual selection and is associated with rapid diversification in several animal groups, yet studies using phylogenetic comparative methods to explicitly test for an association between sexual dichromatism and diversification have produced conflicting results. Sexual dichromatism is rare in frogs, but it is both striking and prevalent in African reed frogs, a major component of the diverse frog radiation termed Afrobatrachia. In contrast to most other vertebrates, reed frogs display female-biased dichromatism in which females undergo color transformation, often resulting in more ornate coloration in females than in males. We produce a robust phylogeny of Afrobatrachia to investigate the evolutionary origins of sexual dichromatism in this radiation and examine whether the presence of dichromatism is associated with increased rates of net diversification. We find that sexual dichromatism evolved once within hyperoliids and was followed by numerous independent reversals to monochromatism. We detect significant diversification rate heterogeneity in Afrobatrachia and find that sexually dichromatic lineages have double the average net diversification rate of monochromatic lineages. By conducting trait simulations on our empirical phylogeny, we demonstrate that our inference of trait-dependent diversification is robust. Although sexual dichromatism in hyperoliid frogs is linked to their rapid diversification and supports macroevolutionary predictions of speciation by sexual selection, the function of dichromatism in reed frogs remains unclear. We propose that reed frogs are a compelling system for studying the roles of natural and sexual selection on the evolution of sexual dichromatism across micro- and macroevolutionary timescales.
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Affiliation(s)
- Daniel M Portik
- Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA.,Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA
| | - Rayna C Bell
- Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA.,Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560-0162, USA
| | - David C Blackburn
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA
| | - Aaron M Bauer
- Department of Biology, Villanova University, 800 Lancaster Avenue, Villanova, PA 19085, USA
| | - Christopher D Barratt
- Department of Environmental Sciences, University of Basel, Basel 4056, Switzerland.,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig 0413, Germany.,Max Planck Institute for Evolutionary Anthropology, Leipzig 0413, Germany
| | - William R Branch
- Port Elizabeth Museum, P.O. Box 11347, Humewood 6013, South Africa.,Department of Zoology, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031, South Africa
| | - Marius Burger
- African Amphibian Conservation Research Group, Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2520, South Africa.,Flora Fauna & Man, Ecological Services Ltd. Tortola, British Virgin, Island
| | - Alan Channing
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2520, South Africa
| | - Timothy J Colston
- Department of Biological Sciences, Florida State University, Tallahassee, FL 32306, USA.,Zoological Natural History Museum, Addis Ababa University, Arat Kilo, Addis Ababa, Ethiopia
| | - Werner Conradie
- Port Elizabeth Museum, P.O. Box 11347, Humewood 6013, South Africa.,School of Natural Resource Management, Nelson Mandela University, George Campus, George 6530, South Africa
| | - J Maximilian Dehling
- Department of Biology, Institute of Sciences, University of Koblenz-Landau, Universitätsstr. 1, D-56070 Koblenz, Germany
| | - Robert C Drewes
- California Academy of Sciences, San Francisco, CA 94118, USA
| | - Raffael Ernst
- Museum of Zoology, Senckenberg Natural History Collections Dresden, Königsbrücker Landstr. 159, Dresden 01109, Germany.,Department of Ecology, Technische Universität Berlin, Rothenburgstr. 12, Berlin 12165, Germany
| | - Eli Greenbaum
- Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, USA
| | - Václav Gvoždík
- The Czech Academy of Sciences, Institute of Vertebrate Biology, Brno, Czech Republic.,Department of Zoology, National Museum, Prague, Czech Republic
| | | | - Annika Hillers
- Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Biodiversity Dynamics, Invalidenstr. 43, Berlin 10115, Germany.,Across the River - A Transboundary Peace Park for Sierra Leone and Liberia, The Royal Society for the Protection of Birds, 164 Dama Road, Kenema, Sierra Leone
| | - Mareike Hirschfeld
- Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Biodiversity Dynamics, Invalidenstr. 43, Berlin 10115, Germany
| | - Gregory F M Jongsma
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA
| | - Jos Kielgast
- Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, Copenhagen 2100, Denmark
| | - Marcel T Kouete
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA
| | - Lucinda P Lawson
- Department of Biological Sciences, University of Cincinnati, 614 Rieveschl Hall, Cincinnati, OH 45220, USA.,Life Sciences, Field Museum of Natural History, 1400 S. Lake Shore Dr., Chicago, IL 60605, USA
| | - Adam D Leaché
- Department of Biology, Burke Museum of Natural History and Culture, University of Washington, Seattle, WA, USA
| | - Simon P Loader
- Life Sciences Department, Natural History Museum, London SW7 5BD, UK
| | - Stefan Lötters
- Biogeography Department, Trier University, Universitätsring 15, Trier 54296, Germany
| | - Arie Van Der Meijden
- CIBIO Research Centre in Biodiversity and Genetic Resources, InBIO, Universidade do Porto, Campus Agrario de Vairão, Rua Padre Armando Quintas, No. 7, 4485-661 Vairão, Vila do Conde, Portugal
| | - Michele Menegon
- Tropical Biodiversity Section, Science Museum of Trento, Corso del lavoro e della Scienza 3, Trento 38122, Italy
| | - Susanne Müller
- Biogeography Department, Trier University, Universitätsring 15, Trier 54296, Germany
| | - Zoltán T Nagy
- Royal Belgian Institute of Natural Sciences, OD Taxonomy and Phylogeny, Rue Vautier 29, B-1000 Brussels, Belgium
| | | | - Annemarie Ohler
- Département Origines et Evolution, Muséum National d'Histoire Naturelle, UMR 7205 ISYEB, 25 rue Cuvier, Paris 75005, France
| | | | - Daniela Rößler
- Biogeography Department, Trier University, Universitätsring 15, Trier 54296, Germany
| | - Ulrich Sinsch
- Department of Biology, Institute of Sciences, University of Koblenz-Landau, Universitätsstr. 1, D-56070 Koblenz, Germany
| | - Mark-Oliver Rödel
- Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Biodiversity Dynamics, Invalidenstr. 43, Berlin 10115, Germany
| | - Michael Veith
- Biogeography Department, Trier University, Universitätsring 15, Trier 54296, Germany
| | - Jens Vindum
- California Academy of Sciences, San Francisco, CA 94118, USA
| | - Ange-Ghislain Zassi-Boulou
- Institut National de Recherche en Sciences Exactes et Naturelles, Brazzaville BP 2400, République du Congo
| | - Jimmy A McGuire
- Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
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24
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Metcalf CJE, Roth O, Graham AL. Why leveraging sex differences in immune trade-offs may illuminate the evolution of senescence. Funct Ecol 2020; 34:129-140. [PMID: 32063662 PMCID: PMC7006808 DOI: 10.1111/1365-2435.13458] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 09/10/2019] [Indexed: 12/15/2022]
Abstract
The immune system affects senescence (declines in probabilities of survival or reproduction with age), by shaping late age vulnerability to chronic inflammatory diseases and infections. It is also a dynamic interactive system that must balance competing demands across the life course. Thus, immune system function remains an important frontier in understanding the evolution of senescence.Here, we review our expanding mechanistic understanding of immune function over the life course, in the context of theoretical predictions from life-history evolution. We are especially interested in stage- and sex-dependent costs and benefits of investment in the immune system, given differential life-history priorities of the life stages and sexes.We introduce the costs likely to govern immune allocation across the life course. We then discuss theoretical expectations for differences between the sexes and their likely consequences in terms of how the immune system is both modulated by and may modulate senescence, building on information from life-history theory, experimental immunology and demography.We argue that sex differences in immune function provide a potentially powerful probe of selection pressures on the immune system across the life course. In particular, differences in 'competing' and 'caring' between the sexes have evolved across the tree of life, providing repeated instances of divergent selection pressures on immune function occurring within the same overall bauplan.We conclude by detailing an agenda for future research, including development of theoretical predictions of the differences between the sexes under an array of existing models for sex differences in immunity, and empirical tests of such predictions across the tree of life. A free http://onlinelibrary.wiley.com/doi/10.1111/1365-2435.13458/suppinfo can be found within the Supporting Information of this article.
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Affiliation(s)
| | - Olivia Roth
- GEOMAR, Marine Evolutionary EcologyHelmholtz Centre for Ocean ResearchKielGermany
| | - Andrea L. Graham
- Department of Ecology and Evolutionary BiologyPrinceton UniversityPrincetonNJUSA
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25
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Madrid JE, Parker KJ, Ophir AG. Variation, plasticity, and alternative mating tactics: Revisiting what we know about the socially monogamous prairie vole. ADVANCES IN THE STUDY OF BEHAVIOR 2020. [DOI: 10.1016/bs.asb.2020.02.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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26
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Muñoz-Arroyo S, Martínez-Rincón RO, Findley LT, Hernández-Olalde L, Balart EF. Reproductive behaviors and sex roles during a diurnal cycle of the goby, Lythrypnus pulchellus (Teleostei: Gobiidae). J ETHOL 2019. [DOI: 10.1007/s10164-019-00624-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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27
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Baker J, Humphries S, Ferguson-Gow H, Meade A, Venditti C. Rapid decreases in relative testes mass among monogamous birds but not in other vertebrates. Ecol Lett 2019; 23:283-292. [PMID: 31755210 PMCID: PMC6973093 DOI: 10.1111/ele.13431] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 07/26/2019] [Accepted: 10/16/2019] [Indexed: 01/14/2023]
Abstract
Larger testes produce more sperm and therefore improve reproductive success in the face of sperm competition. Adaptation to social mating systems with relatively high and low sperm competition are therefore likely to have driven changes in relative testes size in opposing directions. Here, we combine the largest vertebrate testes mass dataset ever collected with phylogenetic approaches for measuring rates of morphological evolution to provide the first quantitative evidence for how relative testes mass has changed over time. We detect explosive radiations of testes mass diversity distributed throughout the vertebrate tree of life: bursts of rapid change have been frequent during vertebrate evolutionary history. In socially monogamous birds, there have been repeated rapid reductions in relative testes mass. We see no such pattern in other monogamous vertebrates; the prevalence of monogamy in birds may have increased opportunities for investment in alternative behaviours and physiologies allowing reduced investment in expensive testes.
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Affiliation(s)
- Joanna Baker
- School of Biological Sciences, University of Reading, Reading, RG6 6BX, UK
| | - Stuart Humphries
- School of Life Sciences, University of Lincoln, Joseph Banks Laboratories, Green Lane, Lincoln, LN6 7DL, UK
| | - Henry Ferguson-Gow
- Department of Genetics, Evolution and Environment, Centre for Biodiversity and Environment Research, University College London, Gower Street, London, WC1E 6BT, UK
| | - Andrew Meade
- School of Biological Sciences, University of Reading, Reading, RG6 6BX, UK
| | - Chris Venditti
- School of Biological Sciences, University of Reading, Reading, RG6 6BX, UK
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28
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Grebe NM, Fitzpatrick C, Sharrock K, Starling A, Drea CM. Organizational and activational androgens, lemur social play, and the ontogeny of female dominance. Horm Behav 2019; 115:104554. [PMID: 31276664 DOI: 10.1016/j.yhbeh.2019.07.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 06/06/2019] [Accepted: 07/01/2019] [Indexed: 11/18/2022]
Abstract
The role of androgens in shaping "masculine" traits in males is a core focus in behavioral endocrinology, but relatively little is known about an androgenic role in female aggression and social dominance. In mammalian models of female dominance, including the ring-tailed lemur (Lemur catta), links to androgens in adulthood are variable. We studied the development of ring-tailed lemurs to address the behavioral basis and ontogenetic mechanisms of female dominance. We measured behavior and serum androgen concentrations in 24 lemurs (8 males, 16 females) from infancy to early adulthood, and assessed their 'prenatal' androgen milieu using serum samples obtained from their mothers during gestation. Because logistical constraints limited the frequency of infant blood sampling, we accounted for asynchrony between behavioral and postnatal hormone measurements via imputation procedures. Imputation was unnecessary for prenatal hormone measurements. The typical sex difference in androgen concentrations in young lemurs was consistent with adult conspecifics and most other mammals; however, we found no significant sex differences in rough-and-tumble play. Female (but not male) aggression increased beginning at approximately 15 months, coincident with female puberty. In our analyses relating sexually differentiated behavior to androgens, we found no relationship with activational hormones, but several significant relationships with organizational hormones. Notably, associations of prenatal androstenedione and testosterone with behavior were differentiated, both by offspring sex and by type of behavior within offspring sexes. We discuss the importance of considering (1) missing data in behavioral endocrinology research, and (2) organizational androgens other than testosterone in studies of female dominance.
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Affiliation(s)
- Nicholas M Grebe
- Department of Evolutionary Anthropology, Duke University, Durham, NC, USA.
| | | | - Katherine Sharrock
- Department of Evolutionary Anthropology, Duke University, Durham, NC, USA
| | - Anne Starling
- Department of Evolutionary Anthropology, Duke University, Durham, NC, USA
| | - Christine M Drea
- Department of Evolutionary Anthropology, Duke University, Durham, NC, USA; Department of Biology, Duke University, Durham, NC, USA; University Program in Ecology, Duke University, Durham, NC, USA
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29
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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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30
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Rico-Guevara A, Hurme KJ. Intrasexually selected weapons. Biol Rev Camb Philos Soc 2019; 94:60-101. [PMID: 29924496 DOI: 10.1111/brv.12436] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 05/14/2018] [Accepted: 05/18/2018] [Indexed: 01/24/2023]
Abstract
We propose a practical concept that distinguishes the particular kind of weaponry that has evolved to be used in combat between individuals of the same species and sex, which we term intrasexually selected weapons (ISWs). We present a treatise of ISWs in nature, aiming to understand their distinction and evolution from other secondary sex traits, including from 'sexually selected weapons', and from sexually dimorphic and monomorphic weaponry. We focus on the subset of secondary sex traits that are the result of same-sex combat, defined here as ISWs, provide not previously reported evolutionary patterns, and offer hypotheses to answer questions such as: why have only some species evolved weapons to fight for the opposite sex or breeding resources? We examined traits that seem to have evolved as ISWs in the entire animal phylogeny, restricting the classification of ISW to traits that are only present or enlarged in adults of one of the sexes, and are used as weapons during intrasexual fights. Because of the absence of behavioural data and, in many cases, lack of sexually discriminated series from juveniles to adults, we exclude the fossil record from this review. We merge morphological, ontogenetic, and behavioural information, and for the first time thoroughly review the tree of life to identify separate evolution of ISWs. We found that ISWs are only found in bilateral animals, appearing independently in nematodes, various groups of arthropods, and vertebrates. Our review sets a reference point to explore other taxa that we identify with potential ISWs for which behavioural or morphological studies are warranted. We establish that most ISWs come in pairs, are located in or near the head, are endo- or exoskeletal modifications, are overdeveloped structures compared with those found in females, are modified feeding structures and/or locomotor appendages, are most common in terrestrial taxa, are frequently used to guard females, territories, or both, and are also used in signalling displays to deter rivals and/or attract females. We also found that most taxa lack ISWs, that females of only a few species possess better-developed weapons than males, that the cases of independent evolution of ISWs are not evenly distributed across the phylogeny, and that animals possessing the most developed ISWs have non-hunting habits (e.g. herbivores) or are faunivores that prey on very small prey relative to their body size (e.g. insectivores). Bringing together perspectives from studies on a variety of taxa, we conceptualize that there are five ways in which a sexually dimorphic trait, apart from the primary sex traits, can be fixed: sexual selection, fecundity selection, parental role division, differential niche occupation between the sexes, and interference competition. We discuss these trends and the factors involved in the evolution of intrasexually selected weaponry in nature.
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Affiliation(s)
- Alejandro Rico-Guevara
- Department of Integrative Biology, University of California, Berkeley, 3040 Valley Life Sciences Building, Berkeley, CA, 94720, U.S.A.,Department of Ecology and Evolutionary Biology, University of Connecticut, 75 N. Eagleville Rd, Unit 3043, Storrs, CT, 06269, U.S.A.,Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Código Postal 11001, Bogotá DC, Colombia
| | - Kristiina J Hurme
- Department of Integrative Biology, University of California, Berkeley, 3040 Valley Life Sciences Building, Berkeley, CA, 94720, U.S.A.,Department of Ecology and Evolutionary Biology, University of Connecticut, 75 N. Eagleville Rd, Unit 3043, Storrs, CT, 06269, U.S.A
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31
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Hare RM, Simmons LW. Sexual selection and its evolutionary consequences in female animals. Biol Rev Camb Philos Soc 2018; 94:929-956. [DOI: 10.1111/brv.12484] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 10/31/2018] [Accepted: 11/02/2018] [Indexed: 01/01/2023]
Affiliation(s)
- Robin M. Hare
- Centre for Evolutionary Biology, School of Biological Sciences University of Western Australia 35 Stirling Highway, Perth, 6009 Australia
| | - Leigh W. Simmons
- Centre for Evolutionary Biology, School of Biological Sciences University of Western Australia 35 Stirling Highway, Perth, 6009 Australia
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32
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Amundsen T. Sex roles and sexual selection: lessons from a dynamic model system. Curr Zool 2018; 64:363-392. [PMID: 30402079 PMCID: PMC6007278 DOI: 10.1093/cz/zoy036] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 04/24/2018] [Indexed: 12/21/2022] Open
Abstract
Our understanding of sexual selection has greatly improved during the last decades. The focus is no longer solely on males, but also on how female competition and male mate choice shape ornamentation and other sexually selected traits in females. At the same time, the focus has shifted from documenting sexual selection to exploring variation and spatiotemporal dynamics of sexual selection, and their evolutionary consequences. Here, I review insights from a model system with exceptionally dynamic sexual selection, the two-spotted goby fish Gobiusculus flavescens. The species displays a complete reversal of sex roles over a 3-month breeding season. The reversal is driven by a dramatic change in the operational sex ratio, which is heavily male-biased at the start of the season and heavily female-biased late in the season. Early in the season, breeding-ready males outnumber mature females, causing males to be highly competitive, and leading to sexual selection on males. Late in the season, mating-ready females are in excess, engage more in courtship and aggression than males, and rarely reject mating opportunities. With typically many females simultaneously courting available males late in the season, males become selective and prefer more colorful females. This variable sexual selection regime likely explains why both male and female G. flavescens have ornamental colors. The G. flavescens model system reveals that sexual behavior and sexual selection can be astonishingly dynamic in response to short-term fluctuations in mating competition. Future work should explore whether sexual selection is equally dynamic on a spatial scale, and related spatiotemporal dynamics.
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Affiliation(s)
- Trond Amundsen
- Department of Biology, Norwegian University of Science and Technology, NO 7491 Trondheim, Norway
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33
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34
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Zizzari ZV, Jessen A, Koene JM. Male reproductive suppression: not a social affair. Curr Zool 2018; 63:573-579. [PMID: 29492017 PMCID: PMC5804194 DOI: 10.1093/cz/zow089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 07/27/2016] [Indexed: 12/16/2022] Open
Abstract
In the animal kingdom there are countless strategies via which males optimize their reproductive success when faced with male–male competition. These male strategies typically fall into two main categories: pre- and post-copulatory competition. Within these 2 categories, a set of behaviors, referred to as reproductive suppression, is known to cause inhibition of reproductive physiology and/or reproductive behavior in an otherwise fertile individual. What becomes evident when considering examples of reproductive suppression is that these strategies conventionally encompass reproductive interference strategies that occur between members of a hierarchical social group. However, mechanisms aimed at impairing a competitor’s reproductive output are also present in non-social animals. Yet, current thinking emphasizes the importance of sociality as the primary driving force of reproductive suppression. Therefore, the question arises as to whether there is an actual difference between reproductive suppression strategies in social animals and equivalent pre-copulatory competition strategies in non-social animals. In this perspective paper we explore a broad taxonomic range of species whose individuals do not repeatedly interact with the same individuals in networks and yet, depress the fitness of rivals. Examples like alteration of male reproductive physiology, female mimicry, rival spermatophore destruction, and cementing the rival’s genital region in non-social animals, highlight that male pre-copulatory reproductive suppression and male pre-copulatory competition overlap. Finally, we highlight that a distinction between male reproductive interference in animals with and without a social hierarchy might obscure important similarities and does not help to elucidate why different proximate mechanisms evolved. We therefore emphasize that male reproductive suppression need not be restricted to social animals.
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Affiliation(s)
- Z Valentina Zizzari
- Department of Ecological Science-Animal Ecology, VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Andrea Jessen
- Department of Ecological Science-Animal Ecology, VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Joris M Koene
- Department of Ecological Science-Animal Ecology, VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
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35
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36
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Rendon NM, Amez AC, Proffitt MR, Bauserman ER, Demas GE. Aggressive behaviours track transitions in seasonal phenotypes of female Siberian hamsters. Funct Ecol 2017; 31:1071-1081. [PMID: 28757672 PMCID: PMC5526640 DOI: 10.1111/1365-2435.12816] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Seasonally breeding animals exhibit profound physiological and behavioural responses to changes in ambient day length (photoperiod), including changes in reproductive function and territorial aggression.Species where aggression persists when gonads are regressed and circulating levels of gonadal hormones are low, such as Siberian hamsters (Phodopus sungorus) and song sparrows (Melospiza melodia), challenge the well-established framework that gonadal hormones are important mediators of aggression.A solution to this apparent paradox is that a season-specific increase in sensitivity to hormones in brain areas associated with aggression offsets low levels of gonadal hormones during periods of reproductive quiescence.To test this hypothesis, we manipulated photoperiod to induce natural fluctuations in seasonal phenotype across multiple stages of the annual reproductive cycle in female Siberian hamsters that display increased aggression during short-day reproductive quiescence, suggesting that behaviour persists independent of gonadal steroids.Females were housed in long "summer" days or short "winter" days for 10, 24 or 30 weeks to capture gonadal regression, transition back to a reproductively functional state and full gonadal recrudescence, respectively.Long-day animals maintained reproductive functionality and displayed low aggression across all time points. By week 10, short-day reproductively responsive females underwent gonadal regression and displayed increased aggression; non-responsive animals showed no such changes. At week 24, animals were in a transitional period and displayed an intermediate phenotype with respect to reproduction and aggression. By week 30, short-day females were fully recrudesced and returned to long-day-like levels of aggression.Consistent with our hypothesis, gonadally regressed females displayed decreases in 17β-oestradiol (oestradiol) levels, but site-specific increases in the abundance of brain oestrogen receptor-alpha (ERα) in regions associated with aggression, but not reproduction. Increased site-specific ERα may function as a compensatory mechanism to allow increased responsiveness to oestradiol in regulating aggression in lieu of high circulating concentrations of hormones.Collectively, these results broaden our understanding of how breeding phenology maps onto social behaviour and the mechanisms that have evolved to coordinate behaviours that occur in non-breeding contexts.
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Affiliation(s)
- Nikki M Rendon
- Department of Biology, Center for the Integrative Study of Animal Behavior, Program in Neuroscience, Indiana University, Bloomington, IN 47405, USA
| | - Andrea C Amez
- Department of Biology, Center for the Integrative Study of Animal Behavior, Program in Neuroscience, Indiana University, Bloomington, IN 47405, USA
| | - Melissa R Proffitt
- Department of Biology, Center for the Integrative Study of Animal Behavior, Program in Neuroscience, Indiana University, Bloomington, IN 47405, USA
| | - Elizabeth R Bauserman
- Department of Biology, Center for the Integrative Study of Animal Behavior, Program in Neuroscience, Indiana University, Bloomington, IN 47405, USA
| | - Gregory E Demas
- Department of Biology, Center for the Integrative Study of Animal Behavior, Program in Neuroscience, Indiana University, Bloomington, IN 47405, USA
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37
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Geary DC. Evolution of Sex Differences in Trait- and Age-Specific Vulnerabilities. PERSPECTIVES ON PSYCHOLOGICAL SCIENCE 2016; 11:855-876. [DOI: 10.1177/1745691616650677] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Traits that facilitate competition for reproductive resources or that influence mate choice generally have a heightened sensitivity to stressors. They have evolved to signal resilience to infectious disease and nutritional and social stressors, and they are compromised by exposure to man-made toxins. Although these traits can differ from one species or sex to the next, an understanding of the dynamics of competition and choice can in theory be used to generate a priori predictions about sex-, age-, and trait-specific vulnerabilities for any sexually reproducing species. I provide a review of these dynamics and illustrate associated vulnerabilities in nonhuman species. The age- and sex-specific vulnerability of such traits is then illustrated for stressor-related disruptions of boys’ and girls’ physical growth and play behavior, as well as for aspects of boys’ and girls’ and men’s and women’s personality, language, and spatial abilities. There is much that remains to be determined, but enough is now known to reframe trait sensitivity in ways that will allow scientists and practitioners to better identify and understand vulnerable human traits, and eventually ameliorate or prevent their expression.
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38
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Davies CS, Smyth KN, Greene LK, Walsh DA, Mitchell J, Clutton-Brock T, Drea CM. Exceptional endocrine profiles characterise the meerkat: sex, status, and reproductive patterns. Sci Rep 2016; 6:35492. [PMID: 27752129 PMCID: PMC5067592 DOI: 10.1038/srep35492] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 09/30/2016] [Indexed: 11/17/2022] Open
Abstract
In vertebrates, reproductive endocrine concentrations are strongly differentiated by sex, with androgen biases typifying males and estrogen biases typifying females. These sex differences can be reduced in female-dominant species; however, even the most masculinised of females have less testosterone (T) than do conspecific males. To test if aggressively dominant, female meerkats (Suricata suricatta) may be hormonally masculinised, we measured serum androstenedione (A4), T and estradiol (E2) in both sexes and social classes, during both ‘baseline’ and reproductive events. Relative to resident males, dominant females had greater A4, equivalent T and greater E2 concentrations. Males, whose endocrine values did not vary by social status, experienced increased T during reproductive forays, linking T to sexual behaviour, but not social status. Moreover, substantial E2 concentrations in male meerkats may facilitate their role as helpers. In females, dominance status and pregnancy magnified the unusual concentrations of measured sex steroids. Lastly, faecal androgen metabolites replicated the findings derived from serum, highlighting the female bias in total androgens. Female meerkats are thus strongly hormonally masculinised, possibly via A4’s bioavailability for conversion to T. These raised androgen concentrations may explain female aggressiveness in this species and give dominant breeders a heritable mechanism for their daughters’ competitive edge.
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Affiliation(s)
- Charli S Davies
- Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa.,Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA
| | - Kendra N Smyth
- Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa.,Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA.,University Program in Ecology, Duke University, Durham, NC 27708, USA
| | - Lydia K Greene
- Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa.,Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA.,University Program in Ecology, Duke University, Durham, NC 27708, USA
| | - Debbie A Walsh
- Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa.,Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA
| | - Jessica Mitchell
- Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa.,Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA
| | - Tim Clutton-Brock
- Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa.,Mammal Research Institute, University of Pretoria, Pretoria, South Africa.,Department of Zoology, University of Cambridge, Cambridge, UK
| | - Christine M Drea
- Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa.,Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA.,University Program in Ecology, Duke University, Durham, NC 27708, USA.,Department of Biology, Duke University, Durham, USA
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39
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Fritzsche K, Booksmythe I, Arnqvist G. Sex Ratio Bias Leads to the Evolution of Sex Role Reversal in Honey Locust Beetles. Curr Biol 2016; 26:2522-2526. [PMID: 27593373 DOI: 10.1016/j.cub.2016.07.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 07/05/2016] [Accepted: 07/08/2016] [Indexed: 11/29/2022]
Abstract
The reversal of conventional sex roles was enigmatic to Darwin, who suggested that it may evolve when sex ratios are female biased [1]. Here we present direct evidence confirming Darwin's hypothesis. We investigated mating system evolution in a sex-role-reversed beetle (Megabruchidius dorsalis) using experimental evolution under manipulated sex ratios and food regimes. In female-biased populations, where reproductive competition among females was intensified, females evolved to be more attractive and the sex roles became more reversed. Interestingly, female-specific mating behavior evolved more rapidly than male-specific mating behavior. We show that sexual selection due to reproductive competition can be strong in females and can target much the same traits as in males of species with conventional mating systems. Our study highlights two central points: the role of ecology in directing sexual selection and the role that females play in mating system evolution.
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Affiliation(s)
- Karoline Fritzsche
- Department of Zoology, University of Graz, Universitätsplatz 2, 8010 Graz, Austria.
| | - Isobel Booksmythe
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Göran Arnqvist
- Animal Ecology, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, 752 36 Uppsala, Sweden
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40
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Giroux MA, Ditlecadet D, Martin LJ, Lanctot RB, Lecomte N. Sexing a sex-role-reversed species based on plumage: potential challenges in the red phalarope. PeerJ 2016; 4:e1989. [PMID: 27168992 PMCID: PMC4860308 DOI: 10.7717/peerj.1989] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 04/08/2016] [Indexed: 12/04/2022] Open
Abstract
Sex-role reversal, in which males care for offspring, can occur when mate competition is stronger between females than males. Secondary sex traits and mate attracting displays in sex-role-reversed species are usually more pronounced in females than in males. The red phalarope (Phalaropus fulicarius) is a textbook example of a sex-role-reversed species. It is generally agreed that males are responsible for all incubation and parental care duties, whereas females typically desert males after having completed a clutch and may pair with new males to lay additional clutches. The breeding plumage of female red phalaropes is usually more brightly colored than male plumage, a reversed sexual dichromatism usually associated with sex-role reversal. Here, we confirm with PCR-based sexing that male red phalaropes can exhibit both the red body plumage typical of a female and the incubation behavior typical of a male. Our result, combined with previous observations of brightly colored red phalaropes incubating nests at the same arctic location (Igloolik Island, Nunavut, Canada), suggests that plumage dichromatism alone may not be sufficient to distinguish males from females in this breeding population of red phalaropes. This stresses the need for more systematic genetic sexing combined with standardized description of intersexual differences in red phalarope plumages. Determining whether such female-like plumage on males is a result of phenotypic plasticity or genetic variation could contribute to further understanding sex-role reversal strategies in the short Arctic summer.
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Affiliation(s)
- Marie-Andrée Giroux
- Canada Research Chair in Polar and Boreal Ecology, Université de Moncton, Moncton, Canada; Centre d'Études Nordiques, Université du Québec à Rimouski, Rimouski, Canada; Canada Research Chair on Northern Biodiversity, Université du Québec à Rimouski, Rimouski, Canada
| | | | - Luc J Martin
- Département de Biologie, Université de Moncton , Moncton , Canada
| | - Richard B Lanctot
- Migratory Bird Management, US Fish and Wildlife Service , Anchorage, AK , USA
| | - Nicolas Lecomte
- Canada Research Chair in Polar and Boreal Ecology, Université de Moncton, Moncton, Canada; Centre d'Études Nordiques, Université du Québec à Rimouski, Rimouski, Canada; Département de Biologie, Université de Moncton, Moncton, Canada; Québec Center for Biodiversity Science, Université du Québec à Rimouski, Rimouski, Canada
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41
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Chan YC. Neural Correlates of Sex/Gender Differences in Humor Processing for Different Joke Types. Front Psychol 2016; 7:536. [PMID: 27199791 PMCID: PMC4844976 DOI: 10.3389/fpsyg.2016.00536] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 03/31/2016] [Indexed: 11/25/2022] Open
Abstract
Humor operates through a variety of techniques, which first generate surprise and then amusement and laughter once the unexpected incongruity is resolved. As different types of jokes use different techniques, the corresponding humor processes also differ. The present study builds on the framework of the 'tri-component theory of humor,' which details the mechanisms involved in cognition (comprehension), affect (appreciation), and laughter (expression). This study seeks to identify differences among joke types and between sexes/genders in the neural mechanisms underlying humor processing. Three types of verbal jokes, bridging-inference jokes (BJs), exaggeration jokes (EJs), and ambiguity jokes (AJs), were used as stimuli. The findings revealed differences in brain activity for an interaction between sex/gender and joke type. For BJs, women displayed greater activation in the temporoparietal-mesocortical-motor network than men, demonstrating the importance of the temporoparietal junction (TPJ) presumably for 'theory of mind' processing, the orbitofrontal cortex for motivational functions and reward coding, and the supplementary motor area for laughter. Women also showed greater activation than men in the frontal-mesolimbic network associated with EJs, including the anterior (frontopolar) prefrontal cortex (aPFC, BA 10) for executive control processes, and the amygdala and midbrain for reward anticipation and salience processes. Conversely, AJs elicited greater activation in men than women in the frontal-paralimbic network, including the dorsal prefrontal cortex (dPFC) and parahippocampal gyrus. All joke types elicited greater activation in the aPFC of women than of men, whereas men showed greater activation than women in the dPFC. To confirm the findings related to sex/gender differences, random group analysis and within group variance analysis were also performed. These findings help further establish the mechanisms underlying the processing of different joke types for the sexes/genders and provide a neural foundation for a theory of sex/gender differences in humor.
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Affiliation(s)
- Yu-Chen Chan
- Institute of Learning Sciences, National Tsing Hua UniversityHsinchu, Taiwan
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42
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Valentova JV, Varella MAC. Further Steps Toward a Truly Integrative Theory of Sexuality. ARCHIVES OF SEXUAL BEHAVIOR 2016; 45:517-520. [PMID: 26395464 DOI: 10.1007/s10508-015-0630-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Affiliation(s)
- Jaroslava Varella Valentova
- Department of Experimental Psychology, Institute of Psychology, University of São Paulo (USP), São Paulo, 05508-030, Brazil.
| | - Marco Antonio Corrêa Varella
- Department of Experimental Psychology, Institute of Psychology, University of São Paulo (USP), São Paulo, 05508-030, Brazil
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43
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Geary DC. Can Neglected Tropical Diseases Compromise Human Wellbeing in Sex-, Age-, and Trait-Specific Ways? PLoS Negl Trop Dis 2016; 10:e0004489. [PMID: 27077746 PMCID: PMC4831682 DOI: 10.1371/journal.pntd.0004489] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Traits that facilitate competition for reproductive resources or that influence mate choice have evolved to signal resilience to infectious disease and other stressors. As a result, the dynamics of competition and choice can, in theory, be used to generate predictions about sex-, age-, and trait-specific vulnerabilities for any sexually reproducing species, including humans. These dynamics and associated vulnerabilities are reviewed for nonhuman species, focusing on traits that are compromised by exposure to parasites. Using the same approach, sex-, age-, and trait-specific vulnerabilities to parasitic disease are illustrated for children's and adolescent's physical growth and fitness. Suggestions are then provided for widening the assessment of human vulnerabilities to include age-appropriate measures of behavioral (e.g., children's play) and cognitive (e.g., language fluency) traits. These are traits that are likely to be compromised by infection in age- and sex-specific ways. Inclusion of these types of measures in studies of neglected tropic diseases has the potential to provide a more nuanced understanding of how these diseases undermine human wellbeing and may provide a useful means to study the efficacy of associated treatments.
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Affiliation(s)
- David C. Geary
- Department of Psychological Sciences, Interdisciplinary Neuroscience, University of Missouri, Columbia, Missouri, United States of America
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Rose E, Flanagan SP, Jones AG. The Effects of Synthetic Estrogen Exposure on the Sexually Dimorphic Liver Transcriptome of the Sex-Role-Reversed Gulf Pipefish. PLoS One 2015; 10:e0139401. [PMID: 26448558 PMCID: PMC4598134 DOI: 10.1371/journal.pone.0139401] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 09/12/2015] [Indexed: 01/22/2023] Open
Abstract
Species exhibiting sex-role reversal provide an unusual perspective on the evolution of sex roles and sex differences. However, the proximate effects of sex-role reversal are largely unknown. Endocrine disruptors provide an experimental mechanism to address hormonal regulation of sexually dimorphic gene expression in sex-role-reversed taxa. Here, we investigate gene expression patterns in the liver of the sex-role-reversed Gulf pipefish, because the liver is known to be sexually dimorphic and estrogen-regulated in species with conventional sex roles. Using next-generation RNA-sequencing technology (RNA-seq), we detected sexually dimorphic hepatic gene expression patterns, with a total of 482 differentially expressed genes between the sexes in Gulf pipefish. Two-thirds of these genes were over-expressed in females, and the sex-specific transcriptomes of this sex-role-reversed pipefish’s liver were superficially similar to those of fishes with conventional sex-roles. We exposed females, pregnant males, and non-pregnant males to 17α-ethinylestradiol (EE2) at ecologically relevant concentrations of 5ng/L and compared gene expression patterns in the livers of exposed fish to control fish. Several genes that were up-regulated in EE2-exposed males relative to control males were also found to be female-biased in control animals. These genes included several of the classic estrogen biomarkers, such as vitellogenin, choriogenin, and zona pellucida. Thus, estrogen exposure induced feminization of the male liver transcriptome in a sex-role-reversed pipefish. These results suggest that the ancestral state of estrogen-regulated female reproductive physiology has been retained in all sex-role-reversed vertebrates thus far studied, despite substantial evolution of the hormonal regulation of ornamentation and mating behavior in these interesting taxa.
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Affiliation(s)
- Emily Rose
- Department of Biology, Texas A&M University, 3258 TAMU, College Station, Texas, 77845, United States of America
- * E-mail:
| | - Sarah P. Flanagan
- Department of Biology, Texas A&M University, 3258 TAMU, College Station, Texas, 77845, United States of America
| | - Adam G. Jones
- Department of Biology, Texas A&M University, 3258 TAMU, College Station, Texas, 77845, United States of America
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45
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Vasilieva N, Tchabovsky A. A shortage of males causes female reproductive failure in yellow ground squirrels. SCIENCE ADVANCES 2015; 1:e1500401. [PMID: 26601284 PMCID: PMC4646798 DOI: 10.1126/sciadv.1500401] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 08/24/2015] [Indexed: 06/05/2023]
Abstract
Sexual conflict theory suggests that female breeding success is strongly influenced by individual life history and environmental conditions and is much less affected by mate availability. Female mating failure due to a shortage of males remains poorly studied and understood. We present data on the effects of male availability on female breeding success in a wild colony of yellow ground squirrels (Spermophilus fulvus). A female's probability of breeding increased with the local density of males and was higher with higher male-biased operational sex ratio (OSR) but was independent of local female density, female age, and body condition, which are factors commonly assumed to influence female reproduction. The positive effect of male availability (as measured by OSR) on female breeding success was consistent across the years, and we conclude that male limitation contributes to female mating failure. This pattern, which is not commonly recorded in species with conventional sex roles, can be explained by a combination of sociodemographic and life history traits (sex differences in age of maturation, female-skewed adult sex ratio and seasonally varying OSR, solitary living at low population density, and low mobility of females combined with mate-searching tactics of males) that are not confined to S. fulvus. Our findings indicate that the role of female mating failure (due to a shortage of males) in shaping mammalian life history may be underestimated.
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46
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Dittmer DE, Johnson JB, Hibbitts TJ. Sexual Dimorphism and Patch Size Variation in Three Lizard Species Suggests Potential for Sexual Confusion. COPEIA 2015. [DOI: 10.1643/ch-14-108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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47
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Kalinka AT. How did viviparity originate and evolve? Of conflict, co-option, and cryptic choice. Bioessays 2015; 37:721-31. [PMID: 25904118 DOI: 10.1002/bies.201400200] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
I propose that the underlying adaptation enabling the reproductive strategy of birthing live young (viviparity) is retraction of the site of fertilization within the female reproductive tract, and that this evolved as a means of postcopulatory sexual selection. There are three conspicuous aspects associated with viviparity: (i) internal development is a complex trait often accompanied by a suite of secondary adaptations, yet it is unclear how the intermediate state of this trait - egg retention - could have evolved; (ii) viviparity often results in a reduction in fecundity; (iii) viviparity has evolved independently many times across a diverse array of animal groups. Focusing on the Diptera (true flies), I provide explanations for these observations. I further propose that fecundity is not traded-off to enable potential benefits of viviparity, but rather that loss of fecundity is directly selected and egg retention is an indirect consequence - a model that provides a unifying common basis for the ubiquity of viviparity.
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Affiliation(s)
- Alex T Kalinka
- Institute of Population genetics, Vetmeduni, Vienna, Austria
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48
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Valenzuela-Sánchez A, Harding G, Cunningham AA, Chirgwin C, Soto-Azat C. Home range and social analyses in a mouth brooding frog: testing the coexistence of paternal care and male territoriality. J Zool (1987) 2014. [DOI: 10.1111/jzo.12165] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - G. Harding
- The Durrell Institute of Conservation and Ecology; University of Kent; Canterbury UK
| | | | - C. Chirgwin
- Departamento de Investigación; Parque Tantauco; Chiloé Chile
| | - C. Soto-Azat
- Facultad de Ecología y Recursos Naturales; Universidad Andres Bello; Santiago Chile
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49
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Winegard BM, Winegard BM, Deaner RO. Misrepresentations of Evolutionary Psychology in Sex and Gender Textbooks. EVOLUTIONARY PSYCHOLOGY 2014. [DOI: 10.1177/147470491401200301] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Evolutionary psychology has provoked controversy, especially when applied to human sex differences. We hypothesize that this is partly due to misunderstandings of evolutionary psychology that are perpetuated by undergraduate sex and gender textbooks. As an initial test of this hypothesis, we develop a catalog of eight types of errors and document their occurrence in 15 widely used sex and gender textbooks. Consistent with our hypothesis, of the 12 textbooks that discussed evolutionary psychology, all contained at least one error, and the median number of errors was five. The most common types of errors were “Straw Man,” “Biological Determinism,” and “Species Selection.” We conclude by suggesting improvements to undergraduate sex and gender textbooks.
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Affiliation(s)
- Benjamin M. Winegard
- Department of Psychological Science, the University of Missouri, Columbia, MO, USA
| | - Bo M. Winegard
- Department of Psychology, Florida State University, Tallahassee, FL, USA
| | - Robert O. Deaner
- Department of Psychology, Grand Valley State University, Allendale, MI, USA
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50
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Zanollo V, Griggio M, Robertson J, Kleindorfer S. Assortative Pairings in Diamond Firetails (Stagonopleura guttata) are not the Result of Mutual Mate Choice for an Ornament. Ethology 2014. [DOI: 10.1111/eth.12268] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Valeria Zanollo
- School of Biological Sciences; Flinders University of South Australia; Adelaide South Australia
| | - Matteo Griggio
- Konrad Lorenz Institute of Ethology; Department of Integrative Biology and Evolution; University of Veterinary Medicine of Vienna; Vienna Austria
- Department of Biology; University of Padova; Padova Italy
| | - Jeremy Robertson
- School of Biological Sciences; Flinders University of South Australia; Adelaide South Australia
| | - Sonia Kleindorfer
- School of Biological Sciences; Flinders University of South Australia; Adelaide South Australia
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