Adult sex ratios: causes of variation and implications for animal and human societies

Communications Biology, Год журнала: 2022, Номер 5(1)

Опубликована: Ноя. 19, 2022

Abstract Converging lines of inquiry from across the social and biological sciences target adult sex ratio (ASR; proportion males in population) as a fundamental population-level determinant behavior. The ASR, which indicates relative number potential mates to competitors population, frames selective arena for competition, mate choice, interactions. Here we review growing literature, focusing on methodological developments that sharpen knowledge demographic variables underlying ASR variation, experiments enhance understanding consequences imbalance societies, phylogenetic analyses provide novel insights into evolution. We additionally highlight areas where research advances are expected make accelerating contributions sciences, evolutionary biology, biodiversity conservation.

Язык: Английский

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Multivariate Models of Animal Sex: Breaking Binaries Leads to a Better Understanding of Ecology and Evolution

Integrative and Comparative Biology, Год журнала: 2023, Номер 63(4), С. 891 - 906

Опубликована: Май 8, 2023

"Sex" is often used to describe a suite of phenotypic and genotypic traits an organism related reproduction. However, these traits-gamete type, chromosomal inheritance, physiology, morphology, behavior, etc.-are not necessarily coupled, the rhetorical collapse variation into single term elides much complexity inherent in sexual phenotypes. We argue that consideration "sex" as constructed category operating at multiple biological levels opens up new avenues for inquiry our study variation. apply this framework three case studies illustrate diversity sex variation, from decoupling phenotypes evolutionary ecological consequences intrasexual polymorphisms. instead assuming binary systems, some may be better categorized multivariate nonbinary. Finally, we conduct meta-analysis terms scientific literature highlight how model can clarify, rather than cloud, within across species. such expanded equips us understand processes, biologists, it incumbent upon push back against misunderstandings biology enact harm on marginalized communities.

Язык: Английский

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Biological sex is binary, even though there is a rainbow of sex roles

BioEssays, Год журнала: 2022, Номер 45(2)

Опубликована: Дек. 21, 2022

Biomedical and social scientists are increasingly calling the biological sex into question, arguing that is a graded spectrum rather than binary trait. Leading science journals have been adopting this relativist view, thereby opposing fundamental facts. While we fully endorse efforts to create more inclusive environment for gender-diverse people, does not require denying sex. On contrary, rejection of seems be based on lack knowledge about evolution it champions species chauvinism, inasmuch as imposes human identity notions millions other species. We argue definition sexes remains central recognising diversity life. Humans with their unique combination gender different from non-human animals plants in respect. Denying concept sex, whatever cause, ultimately erodes scientific progress may open flood gates "alternative truths."

Язык: Английский

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Early‐life food stress hits females harder than males in insects: A meta‐analysis of sex differences in environmental sensitivity

Ecology Letters, Год журнала: 2023, Номер 26(8), С. 1419 - 1431

Опубликована: Май 10, 2023

Abstract Fitness consequences of early‐life environmental conditions are often sex‐specific, but corresponding evidence for invertebrates remains inconclusive. Here, we use meta‐analysis to evaluate sex‐specific sensitivity larval nutritional in insects. Using literature‐derived data 85 species with broad phylogenetic and ecological coverage, show that females generally more sensitive food stress than males. Stressful during development typically lead female‐biased mortality thus increasingly male‐biased sex ratios emerging adults. We further demonstrate the general trend higher can primarily be attributed their larger body size insects hence energy needs development. By contrast, there is no consistent sex‐biased sexually size‐monomorphic species. Drawing conclusions regarding dimorphism wait accumulation relevant data. Our results suggest leading elevated juvenile may potentially affect performance insect populations by reducing proportion among individuals reaching reproductive age. Accounting therefore essential understanding dynamics demography populations, not least importantly context ongoing declines.

Язык: Английский

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

Biology Letters, Год журнала: 2025, Номер 21(2)

Опубликована: Фев. 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

Язык: Английский

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Exploring climate-induced sex-based differences in aquatic and terrestrial ecosystems to mitigate biodiversity loss

Nature Communications, Год журнала: 2023, Номер 14(1)

Опубликована: Авг. 16, 2023

The response of aquatic and terrestrial organisms to climate change can depend on biological sex. A key challenge is unravel the interactive effects sex at individual population levels cascading communities. This new understanding essential improve adaptation mitigation strategies.

Язык: Английский

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Navigating sex and sex roles: deciphering sex-biased gene expression in a species with sex-role reversal ( Syngnathus typhle )

Royal Society Open Science, Год журнала: 2024, Номер 11(4)

Опубликована: Апрель 1, 2024

Sexual dimorphism, the divergence in morphological traits between males and females of same species, is often accompanied by sex-biased gene expression. However, majority research has focused on species with conventional sex roles, where have highest energy burden both egg production parental care, neglecting diversity reproductive roles found nature. We investigated expression

Язык: Английский

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The evolution of sex roles: The importance of ecology and social environment

Proceedings of the National Academy of Sciences, Год журнала: 2024, Номер 121(22)

Опубликована: Май 21, 2024

Males and females often have different roles in reproduction, although the origin of these differences has remained controversial. Explaining enigmatic reversed sex where males sacrifice their mating potential provide full parental care is a particularly long-standing challenge evolutionary biology. While most studies focused on ecological factors as drivers roles, recent research highlights significance social such adult ratio. To disentangle propositions, here, we investigate additive interactive effects several role variation using shorebirds (sandpipers, plovers, allies) model organisms that spectrum including some best-known examples sex-role reversal. Our results consistently show play prominent driving roles. Importantly, are associated with both male-skewed ratios high breeding densities. Furthermore, phylogenetic path analyses general support for variations rather than being consequence Together, important open future directions by showing opportunities major generating diversity system, care.

Язык: Английский

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A male-biased sex ratio increases the opportunity for precopulatory sexual selection but does not change the Bateman gradient

Evolution Letters, Год журнала: 2025, Номер unknown

Опубликована: Янв. 17, 2025

Abstract Theory predicts that the sex ratio within populations should influence strength of sexual selection, and is often used as a proxy for selection. However, recent studies challenge this relationship. We manipulated adult ratios in Drosophila melanogaster to comprehensively investigate relationship between Consistent with theory, we found stronger selection males than females an increased variance male reproductive success (the opportunity selection) male-biased ratios. In addition, faced more intense sperm competition ratios, although structure networks was largely invariant ratio. Despite this, show did not measured by Bateman gradient. leverage randomized null models reconcile these results higher may be explained random chance mating, rather competitive mechanisms. Our findings indicate caution warranted over long-standing assumption bias good

Язык: Английский

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Decoding emotional prosody: a unified brain network integrating gender and task type effect

Research Square (Research Square), Год журнала: 2025, Номер unknown

Опубликована: Март 31, 2025

Emotional prosody processing is vital for social communication. Despite numerous neuroimaging studies exploring emotional prosody, results remain inconsistent across studies, and the factors influencing these inconsistencies are unclear. Here, we identified a unified brain network using activation mapping. We evaluated how gender task type influence this network. Results showed broader networks in females compared to males, regardless of type. Moreover, comparison revealed stage mode prosody. Additionally, analyses link specific receptors/transporters (\(\:{5HT}_{1A}\), \(\:{CB}_{1}\), \(\:{mGluR}_{5}\), \(\:NET\)) physiological processes such as synapse extension, energy metabolism, active transmembrane transport, along with diseases like autistic disorder, Alzheimer's disease, general disease progression. In conclusion, findings underscore importance considering effects on research provide deeper understanding complex neural mechanisms underlying

Язык: Английский

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