Emerging insights into the genetics and evolution of human same-sex sexual behavior

Trends in Genetics, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Language: Английский

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Prenatal sex determination illuminates the unusual adult sex ratio of a group-living lemur

Biology Letters, Journal Year: 2025, Volume and Issue: 21(2)

Published: Feb. 1, 2025

Most mammals, including humans, exhibit even or slightly male-biased birth sex ratios (BSRs) and female-biased adult (ASRs) much later in life due to higher male mortality rates. The group-living primates of Madagascar are unusual this respect because they lack ASRs, but it is unknown whether the result skewed BSRs sex-specific disappearance patterns. Using long-term demographic data from wild red-fronted lemurs ( Eulemur rufifrons ), we analysed their ratio dynamics across lifespan. We assessed BSR via prenatal determination using maternal faecal oestrogen metabolite measurements during late pregnancy, confirming a visually determined equal three months after birth, indicating no early mortality. Demographic analyses additionally disclosed female within first 8 years age, likely associated with reproductive effort life. Thereby, survival had greatest positive effect on ASR. Our study offers rare perspective age- primate population, whose sex-reversed patterns may also contribute more general understanding mechanisms generating sex-biased

Language: Английский

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Genetic variants underlying human bisexual behavior are reproductively advantageous

Science Advances, Journal Year: 2024, Volume and Issue: 10(1)

Published: Jan. 3, 2024

Because human same-sex sexual behavior (SSB) is heritable and leads to fewer offspring, how SSB-associated alleles have persisted whether they will remain in populations are of interest. Using the UK Biobank, we address these questions separately for bisexual (BSB) exclusive SSB (eSSB) after confirming their genetic distinction. We discover that male BSB genetically positively correlated with number offspring. This unexpected phenomenon attributable horizontal pleiotropy risk-taking behavior-associated because both offspring controlling abolishes correlation between By contrast, eSSB negatively Our results suggest BSB-associated likely reproductively advantageous, which may explain past persistence predict future maintenance, eSSB-associated being selected against at present.

Language: Английский

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Sexual selection and sexual size dimorphism in animals

Biology Letters, Journal Year: 2021, Volume and Issue: 17(9), P. 20210251 - 20210251

Published: Sept. 1, 2021

Sexual selection is often considered as a critical evolutionary force promoting sexual size dimorphism (SSD) in animals. However, empirical evidence for positive relationship between on males and male-biased SSD received mixed support depending the studied taxonomic group method used to quantify selection. Here, we present meta-analytic approach accounting phylogenetic non-independence test how standardized metrics of opportunity strength pre-copulatory relate across broad range animal taxa comprising up 95 effect sizes from 59 species. We found that based length measurements was correlated with sex difference but showed weak statistically non-significant Bateman gradient. These findings suggest plays limited role evolution context.

Language: Английский

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Strength, mating success, and immune and nutritional costs in a population sample of US women and men: A registered report

Evolution and Human Behavior, Journal Year: 2025, Volume and Issue: 46(1), P. 106647 - 106647

Published: Jan. 1, 2025

Language: Английский

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Sexual conflict underlying external female genital mutilation in spiders: assessing whether females benefit from multiple matings

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2025, Volume and Issue: 292(2039)

Published: Jan. 1, 2025

External female genital mutilation (EFGM) is a type of traumatic mating in which males damage genitalia, resulting the loss re-mating ability. This study examined whether sexual conflict underlies EFGM by examining possible reproductive costs from decreased number matings spider, Cyclosa argenteoalba . The typically receives sperm male twice during bout. We manipulated both and partners females compared their outputs. results indicated that receiving three times—equivalent to one half two males—laid more egg sacs with eggs per sac than control received male. laid fewer once. There was no significant difference output between males. These indicate benefit multiple but not males, supporting hypothesis. Our has implications for our understanding evolution harmful mating.

Language: Английский

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Temperature Drives the Evolutionary Diversification of Male Harm in Drosophila melanogaster Flies

Ecology Letters, Journal Year: 2025, Volume and Issue: 28(3)

Published: March 1, 2025

Sexual selection often leads to sexual conflict via pre-copulatory (harassment) and/or copulatory (traumatic insemination) male harm females, impacting population growth, adaptation and evolutionary rescue. Male mechanisms are diverse taxonomically widespread, but we largely ignore what ecological factors modulate their diversification. Here, conducted experimental evolution under low- (20°C ± 4°C), moderate- (24°C 4°C) high-temperature (28°C regimes in Drosophila melanogaster, a species with harassment seminal fluid proteins (SFPs), show that temperature drives the divergent of conflict. At low-temperature regime, resulted reduced less plastic (i.e., harm) while at it was characterised by responses proteome driven differential expression SFPs. Our results suggest can be key understanding past diversification future (global warming) conflict, maintenance genetic variation traits.

Language: Английский

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Sexual selection: competition for resources provided by mating partners

Behavioral Ecology, Journal Year: 2024, Volume and Issue: 35(3)

Published: March 13, 2024

Abstract Ever since Darwin’s pioneering work, the definition of sexual selection has been subject to recurrent controversies. The main focus a more recent debate centers on whether or not encompasses intra-sexual competition for resources other than gametes. Specifically, it proposed define as access gametes and consider any provided by mates forms natural selection. In this review, I elaborate several drawbacks gamete-centered approach arguing that (1) implies an artificial split pre-copulatory into two indistinguishable processes, (2) hinders identification quantification and, therefore, its distinction from selection, (3) gives rise overly male-biased perception (4) does conform original conception. attempt provide definition, which is explicit regarding ultimate target competition, propose reproductive potential mating partners. specify characteristics alternative in context previous ones discuss limitations.

Language: Английский

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Extra‐pair paternity and sexual dimorphism in birds

Journal of Evolutionary Biology, Journal Year: 2023, Volume and Issue: 36(5), P. 764 - 779

Published: March 27, 2023

Abstract Differences in the strength of sexual selection between males and females can lead to dimorphism. Extra‐pair paternity (EPP) increase variance male reproductive success hence opportunity for selection. Previous research on birds suggests that EPP drives evolution dimorphism plumage colour body size. Because increases intensity males, it should increased species with larger or more colourful but decreased females. We explored covariation wing length colouration 401 bird species, while controlling other, potentially confounding variables. Wing was associated positively frequency EPP, also social polygamy, sex bias parental behaviour size negatively migration distance. The only predictor In support our prediction, high levels were dichromatism, which are those colourful. Contrary rates both male‐ female‐biased results a role two forms weakly correlated predicted by different reproductive, life‐history traits, suggesting an independent evolution.

Language: Английский

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Population density affects sexual selection in an insect model

Functional Ecology, Journal Year: 2023, Volume and Issue: 37(10), P. 2734 - 2747

Published: July 31, 2023

Abstract Understanding the impact of demographic and ecological factors on strength sexual selection is pivotal to predict eco‐evolutionary dynamics in populations facing environmental change. Density expected show pervasive intra‐ interspecific variation natural populations, but its effect remains largely unexplored. We tested experimentally density standardized metrics male female red flour beetles. Specifically, we explored effects during mating by manipulating size groups arena. found that higher densities imposed a larger group amplified opportunity for pre‐copulatory females and, smaller extent, also males. Moreover, males, detected post‐copulatory groups. By contrast, differences arena resulted steeper gradient. Overall, these data suggest an important factor contributing tremendous within among species. Read free Plain Language Summary this article Journal blog.

Language: Английский

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