Biology Letters最新文献_第4页

Pigment contribution to feather mass depends on melanin form and is restricted to approximately 25. 色素对羽毛质量的贡献取决于黑色素的形式，限制在大约25。

IF 3 2区生物学

Biology Letters Pub Date : 2025-08-01 Epub Date: 2025-08-20 DOI: 10.1098/rsbl.2025.0299

Ismael Galván, Julene Gómez-Vicioso

{"title":"Pigment contribution to feather mass depends on melanin form and is restricted to approximately 25.","authors":"Ismael Galván, Julene Gómez-Vicioso","doi":"10.1098/rsbl.2025.0299","DOIUrl":"10.1098/rsbl.2025.0299","url":null,"abstract":"Feathers are lightweight keratinous structures that have promoted the evolutionary success of birds by facilitating flight. Complex feathers, however, are believed to have evolved in response to visual functions, meaning a relevant role of pigmentation in feather evolution. The most common pigments in birds are melanins, large polymers synthesized at feather follicles, which thus have the potential to contribute significantly to the mass of feathers and compromise their lightweight nature. This contribution has never been quantified. Here, we leveraged a melanin extraction method to measure the mass contribution of different melanin forms to feathers from 19 species of birds, mainly golden eagles Aquila chrysaetos and pied flycatchers Ficedula hypoleuca. Melanin contribution to feather mass averaged 22.3%, but the contribution of eumelanin, responsible for black/grey/dark brown colour phenotypes, was higher than that of pheomelanin, responsible for lighter phenotypes. Eumelanins with a lower content of indole-carboxylated subunits also contributed more to feather mass. Melanin forms do not exert additive effects and constitute approximately 25% of feather mass regardless of whether the pigment composition is mixed or contains a single form. Our findings introduce a novel metabolic cost for flight associated with different plumage phenotypes that may help understand the evolutionary predictors of bird colour diversity.","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"21 8","pages":"20250299"},"PeriodicalIF":3.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12364563/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144882014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Prevalence and implications of sex reversal in free-living birds. 自由生活鸟类性别反转的普遍性及其意义。

IF 3 2区生物学

Biology Letters Pub Date : 2025-08-01 Epub Date: 2025-08-13 DOI: 10.1098/rsbl.2025.0182

Clancy A Hall, Gabriel Conroy, Martina Jelocnik, Vasilli Kasimov, Amber Gillet, Timothy Portas, Andrew Hill, Dominique A Potvin

{"title":"Prevalence and implications of sex reversal in free-living birds.","authors":"Clancy A Hall, Gabriel Conroy, Martina Jelocnik, Vasilli Kasimov, Amber Gillet, Timothy Portas, Andrew Hill, Dominique A Potvin","doi":"10.1098/rsbl.2025.0182","DOIUrl":"10.1098/rsbl.2025.0182","url":null,"abstract":"The ability to unequivocally identify the sex and reproductive status of individuals is crucial across many fields of study. Recent evidence indicates that avian sex determination is more flexible than once believed, with sex-reversed individuals identified in domestic bird populations-that is, individuals exhibiting gonadal and morphological traits of one sex while possessing the chromosomal make-up of the opposite sex. The presence of these individuals can challenge the reliability of traditional sexing methods that rely solely on external morphology, internal anatomy or genetic markers. These methods, when used in isolation, fail to identify sex-reversed or intersex individuals, potentially overlooking their impact on population dynamics. In this pioneering study, we investigated the prevalence of sex-reversed individuals in five common free-living avian species in Queensland, Australia. By comparing internal and external morphological characteristics with polymerase chain reaction results from sex-linked molecular markers, we identified sex-reversed individuals in all five species, with rates ranging from 3 to 6%. Our findings suggest that sex reversal is a common and potentially widespread phenomenon in avian species.","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"21 8","pages":"20250182"},"PeriodicalIF":3.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12343140/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144833913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mechanical function of the unique alveolar torus in the sabretooth Nimravus brachyops (Nimravidae, Carnivora). 剑齿虎短齿独特齿槽环的机械功能（食肉目，剑齿虎科）。

IF 3 2区生物学

Biology Letters Pub Date : 2025-08-01 Epub Date: 2025-08-27 DOI: 10.1098/rsbl.2025.0208

Z Jack Tseng, Narimane Chatar

{"title":"Mechanical function of the unique alveolar torus in the sabretooth Nimravus brachyops (Nimravidae, Carnivora).","authors":"Z Jack Tseng, Narimane Chatar","doi":"10.1098/rsbl.2025.0208","DOIUrl":"https://doi.org/10.1098/rsbl.2025.0208","url":null,"abstract":"Sabretoothed mammals exemplify some of the most extreme craniodental morphological specializations in vertebrates. Much attention has been devoted to their elongated upper canines; however, not all sabretooths possess the same complex of morphological characteristics associated with sabres, making generalization of the requirements for specialized jaw function difficult. Here, we test the approximately 150-year-old hypothesis that a unique jaw torus seen in a single sabretooth genus, Nimravus, is an adaptation to resist biting forces. We tested a suite of biting scenarios using finite element analysis and found that the inclusion of a torus structure decreased the performance of the mandible in its stiffness and strain resistance but increased simulated bite force as well as efficiency. The presence of a torus also preferentially improved the overall performance of the mandible at higher gape angles, configurations often inferred for sabretooths. Lastly, a potential novel torus-associated portion of the masseter muscle would have further increased bite performance. The strong association between morphology and performance suggests that the torus may have played a mechanical role in mastication, and its apparent unique evolution is another prime example of mosaic evolution in the sabretooth functional morphology.","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"21 8","pages":"20250208"},"PeriodicalIF":3.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12380494/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144941618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Divergence in cuticular wax profiles generates partial behavioural isolation between leaf beetle populations with different dispersal traits. 表皮蜡质分布的差异导致不同传播性状的叶甲虫种群之间的部分行为隔离。

IF 3 2区生物学

Biology Letters Pub Date : 2025-08-01 Epub Date: 2025-08-06 DOI: 10.1098/rsbl.2025.0105

Yuki Chiba, Yoshiki Nomura, Masatoshi Hori

{"title":"Divergence in cuticular wax profiles generates partial behavioural isolation between leaf beetle populations with different dispersal traits.","authors":"Yuki Chiba, Yoshiki Nomura, Masatoshi Hori","doi":"10.1098/rsbl.2025.0105","DOIUrl":"10.1098/rsbl.2025.0105","url":null,"abstract":"Sex pheromones are among the most studied insect mating signals, with their extensive diversity underscoring their crucial role in promoting behavioural isolation during speciation. In Chrysomelidae, cuticular wax (CW), a hydrophobic layer covering the insect cuticle, functions as a mating signal and potentially facilitates behavioural isolation. Male leaf beetles use female CW as a mating signal, and their species-specific profiles prevent heterospecific matings, indicating that divergence in CW profiles may promote reproductive isolation and, hence, contribute to speciation. However, the role of CW as an isolating barrier remains unclear owing to limited knowledge regarding intraspecific divergence in female CW and its coevolution with male preferences. Through chemical analysis and behavioural experiments, we demonstrated that intraspecific divergence in female CW contributes to partial behavioural isolation between leaf beetle populations with different dispersal traits: the flight-capable macropterous and flightless brachypterous forms of Galerucella grisescens (Coleoptera: Chrysomelidae). Our results demonstrated a divergence in female CW and male preferences at the intraspecific level, indicating the potential role of CW as an isolating barrier in Chrysomelidae. Additionally, our findings suggest that diverging dispersal ability can enhance divergence in pheromone communication channels, consistent with previous findings that loss of flight enhances beetle diversification.","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"21 8","pages":"20250105"},"PeriodicalIF":3.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12326271/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144788204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Linking performance to powerhouse: mitochondrial aerobic metabolism in blood cells reflects flight endurance of house sparrows (Passer domesticus). 将性能与动力联系起来：血细胞中的线粒体有氧代谢反映了家雀（Passer domesticus）的飞行耐力。

IF 3 2区生物学

Biology Letters Pub Date : 2025-08-01 Epub Date: 2025-08-06 DOI: 10.1098/rsbl.2025.0199

Riccardo Ton, Max M Gillings, Hector Pacheco-Fuentes, Antoine Stier, Simon C Griffith

{"title":"Linking performance to powerhouse: mitochondrial aerobic metabolism in blood cells reflects flight endurance of house sparrows (Passer domesticus).","authors":"Riccardo Ton, Max M Gillings, Hector Pacheco-Fuentes, Antoine Stier, Simon C Griffith","doi":"10.1098/rsbl.2025.0199","DOIUrl":"10.1098/rsbl.2025.0199","url":null,"abstract":"Identifying the physiological mechanisms underpinning inter-individual differences in performance and fitness remains a key challenge in organismal biology. Variation in mitochondrial aerobic metabolism has been suggested to underlie inter-individual variation in performance, but this remains seldom tested, partly because of the need to use terminal sampling for assessing mitochondrial parameters. To fill this knowledge gap, we investigated whether inter-individual variation in mitochondrial aerobic parameters measured from less-invasively taken samples (i.e. blood cells) would correlate with both anaerobic and aerobic metrics of flight performance in house sparrows (Passer domesticus). We predicted that mitochondrial aerobic metabolism should correlate with aerobic but not anaerobic metrics of flight performance. As expected, we found no evidence for a relationship between mitochondrial metabolism and the energy required to take-off (i.e. anaerobic), but flight duration to exhaustion (i.e. aerobic) correlated positively with both cellular mitochondrial respiration rates and oxidative phosphorylation efficiency, a proxy of mitochondrial efficiency to convert nutrients into ATP. Our results, therefore, support the idea that inter-individual variation in mitochondrial aerobic metabolism could underlie variation in aerobic performance and suggest that the nucleated blood cells of birds (and potentially other non-mammalian vertebrates) may be a relevant biological sample to test those links.","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"21 8","pages":"20250199"},"PeriodicalIF":3.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12326270/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144788207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Temporal trends in allometry of shell calcification in northeastern Pacific venerid bivalves: implications for predicting responses to climate change. 东北太平洋软壳类双壳类异速钙化的时间趋势：对气候变化响应的预测意义。

IF 3 2区生物学

Biology Letters Pub Date : 2025-08-01 Epub Date: 2025-08-20 DOI: 10.1098/rsbl.2025.0181

Elizabeth Bullard, Kaustuv Roy

{"title":"Temporal trends in allometry of shell calcification in northeastern Pacific venerid bivalves: implications for predicting responses to climate change.","authors":"Elizabeth Bullard, Kaustuv Roy","doi":"10.1098/rsbl.2025.0181","DOIUrl":"10.1098/rsbl.2025.0181","url":null,"abstract":"Despite literature spanning almost a century, how allometric relationships of phenotypic traits behave over evolutionary time remains poorly known for most marine species. In particular, the fossil record is seriously underutilized in this context despite harbouring a rich archive of traits. Here we use the late Pleistocene fossil record in San Diego, California, in conjunction with archival and field collected specimens, to quantify temporal changes in allometric relationships between shell size and calcification, two important functional traits, in five different species of marine bivalves. Our results reject the traditional hypothesis that allometric relationships are invariant over time. They also show that temporal changes in allometric relationships are species-specific, with closely related species showing divergent trends. Finally, we argue that information about the nature of long-term changes in allometric relationships of functionally important traits can provide a powerful yet underappreciated tool for understanding species and population responses to climate change.","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"21 8","pages":"20250181"},"PeriodicalIF":3.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12364568/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144882016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Flap-necked chameleons change colour to match their background. 翻领变色龙会根据背景改变颜色。

IF 3 2区生物学

Biology Letters Pub Date : 2025-08-01 Epub Date: 2025-08-06 DOI: 10.1098/rsbl.2025.0134

Tom Major, Alexia C M Hesten, Jan Stipala, Michael A Cant, Martin Stevens, Jolyon Troscianko

引用次数: 0

Late Pleistocene faunal community patterns disrupted by Holocene human impacts. 全新世人类活动破坏了晚更新世动物群落格局。

IF 3 2区生物学

Biology Letters Pub Date : 2025-08-01 Epub Date: 2025-08-13 DOI: 10.1098/rsbl.2025.0151

Barry W Brook, S Kathleen Lyons, Benjamin E Carter, William Gearty, Orlin S Todorov, Zach Aandahl, John Alroy

{"title":"Late Pleistocene faunal community patterns disrupted by Holocene human impacts.","authors":"Barry W Brook, S Kathleen Lyons, Benjamin E Carter, William Gearty, Orlin S Todorov, Zach Aandahl, John Alroy","doi":"10.1098/rsbl.2025.0151","DOIUrl":"10.1098/rsbl.2025.0151","url":null,"abstract":"We analysed fossil mammal assemblages from over 350 Late Pleistocene and Holocene sites worldwide to test whether human activities, such as agriculture, domestication and intensified land use, restructured global patterns of mammal co-occurrence. Using presence-absence data, we contrasted a novel iterative 'chase clustering' method, which is compositionally driven, against a traditional spatially constrained Ward's clustering approach. Both methods recovered continental-scale groupings in the Pleistocene, consistent with known biogeographic boundaries. Holocene land use and domestication reconfigured these historical patterns, creating novel assemblages independent of previous biogeographic constraints. Faunal turnover at the local scale varied substantially across regions, being especially pronounced in the Americas, whereas other areas showed relative stability. Even moderate expansion of domesticates altered how communities grouped, highlighting their disproportionate ecological influence. Our findings demonstrate that human-driven niche modification, beyond earlier megafaunal extinctions, profoundly reshaped mammal communities on a global scale. Recognizing these anthropogenic legacies provides essential context for anticipating how current and future human pressures might further transform biodiversity.","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"21 8","pages":"20250151"},"PeriodicalIF":3.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12343122/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144833912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Exceptional fossils from Peru and an integrative phylogeny reconcile the evolutionary timing and mode of Gavialis and its kin. 来自秘鲁的特殊化石和一个完整的系统发育调和了Gavialis及其近亲的进化时间和模式。

IF 3 2区生物学

Biology Letters Pub Date : 2025-08-01 Epub Date: 2025-08-06 DOI: 10.1098/rsbl.2025.0238

Camila Zamora-Vega, Pedro E Romero, Mario Urbina, Matthieu Carré, Diana Ochoa, Rodolfo Salas-Gismondi

{"title":"Exceptional fossils from Peru and an integrative phylogeny reconcile the evolutionary timing and mode of Gavialis and its kin.","authors":"Camila Zamora-Vega, Pedro E Romero, Mario Urbina, Matthieu Carré, Diana Ochoa, Rodolfo Salas-Gismondi","doi":"10.1098/rsbl.2025.0238","DOIUrl":"10.1098/rsbl.2025.0238","url":null,"abstract":"The acquisition of a long and slender snout (longirostry) resulted in extremely similar morphology across crocodylians and, therefore, raised a conflict between morphological and molecular phylogenetic hypotheses involving the longirostrine living gharials, Gavialis gangeticus and Tomistoma schlegelii. This discrepancy is not only topological but also concerns divergence time estimates for the crown clade Gavialidae, especially due to the inclusion of other longirostrine forms, ancient 'thoracosaurs'-which introduces significant chronostratigraphic inconsistencies. To contribute to reconciling these contrasting lines of evidence, exceptionally preserved fossils of a new Miocene gavialid from Peru were included in a total-evidence Bayesian analysis. Our analysis integrates morphological, molecular and chronostratigraphic data and incorporates most taxa of the largest adaptive radiation of gavialids, which occurred in the Cenozoic of South America and the Caribbean (SAC). Our results demonstrate that including SAC taxa substantially increase divergence estimates for Gavialidae, surpassing those inferred from molecular data alone. The exceptional preservation of the new Peruvian fossils enabled character re-evaluation for gavialids and 'thoracosaurs', the latter recovered even outside Crocodylia and suggesting that longirostry resulted from independent evolution. These findings underscore the crucial role of SAC gavialids in understanding the morphological trajectory and phylogenetics of longirostrine crocodylians.","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"21 8","pages":"20250238"},"PeriodicalIF":3.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12327081/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144788205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Caterpillars suppress nocifensive behaviours during the quiescent 'sphinx' state. 毛毛虫在静止的“狮身人面像”状态下会抑制攻击性行为。

IF 3 2区生物学

Biology Letters Pub Date : 2025-08-01 Epub Date: 2025-08-20 DOI: 10.1098/rsbl.2025.0124

Gayathri Kondakath, Isabel M Messinger, Annushka Veliko-Shapko, Barry Trimmer

{"title":"Caterpillars suppress nocifensive behaviours during the quiescent 'sphinx' state.","authors":"Gayathri Kondakath, Isabel M Messinger, Annushka Veliko-Shapko, Barry Trimmer","doi":"10.1098/rsbl.2025.0124","DOIUrl":"10.1098/rsbl.2025.0124","url":null,"abstract":"Noxious (harmful) stimuli are detected by a specialized sensory process known as nociception, which typically evokes defensive behaviours to minimize tissue damage. While sensitization of nocifensive responses by intense or repetitive stimuli is well-documented in insects, instances of deliberate nociceptive suppression are relatively unexplored, particularly within natural behavioural contexts. Here, we describe a behavioural state in the tobacco hornworm (Manduca sexta), termed the 'sphinx' state, characterized by a distinct ventrally curled posture of the head and thorax following gentle disturbance. One of the striking characteristics of this state is that the larvae exhibit reduced responsiveness to noxious stimuli, indicating nociceptive downregulation. We also observe an overall reduced behavioural responsiveness to innocuous stimuli. Our surgical experiments show that the cerebral ganglion is essential to initiate the sphinx state. Overall, this discovery reveals a novel instance of active behavioural modulation in insects and highlights the flexibility of nociceptive responses, challenging the notion of nociception as strictly hard-wired and stereotyped.","PeriodicalId":9005,"journal":{"name":"Biology Letters","volume":"21 8","pages":"20250124"},"PeriodicalIF":3.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12364565/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144882011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0