Molecular EcologyPub Date : 2025-08-01Epub Date: 2025-07-25DOI: 10.1111/mec.70027
Stephen J Sabatino, M Pilar Cabezas, Paulo Pereira, Susana Garrido, António M Santos, Miguel Carneiro, Paulo T Santos, Bruno Louro, Cymon J Cox, Adelino V M Canário, Ana Veríssimo
{"title":"Inversions Dominate Evolution in the European Sardine (Sardina pilchardus) Amid Strong Gene Flow.","authors":"Stephen J Sabatino, M Pilar Cabezas, Paulo Pereira, Susana Garrido, António M Santos, Miguel Carneiro, Paulo T Santos, Bruno Louro, Cymon J Cox, Adelino V M Canário, Ana Veríssimo","doi":"10.1111/mec.70027","DOIUrl":"10.1111/mec.70027","url":null,"abstract":"<p><p>Inversions can play key roles in the genetic architecture of adaptation, but the scale of their effects across different species remains poorly understood. Here, we use whole-genome sequencing and demographic modelling to investigate the influence of inversions on the population genomics of the r-selected European sardine (Sardina pilchardus). Allele frequency differences from millions of SNPs across 34 populations spanning the species' range were analysed. Genomic scans identified several extreme outlier regions overlapping large inversions (29-52 Mbp), collectively representing over half the genome. Our findings suggest these inversions correlate with locally adapted life-history strategies. First, SNPs within outlier regions containing inversions exhibited striking allele frequency differences between Atlantic and Mediterranean sardines, which differ in key adaptive life-history traits. In the Atlantic, inversion allele frequencies varied latitudinally, while in the Mediterranean, they shifted longitudinally, aligning with temperature and oceanographic features that influence sardine life-history strategies. Moreover, adjacent populations in contrasting environments exhibited pronounced differences in inversion allele frequencies, accompanied by a marked reduction in migration between them. In contrast, spatial patterns at neutral loci showed widespread gene flow, isolation by distance within basins, and population structure between Atlantic and Mediterranean basins (except for the Canary Islands). These results suggest that the inversions studied are under selection and demonstrate the capacity of large inversions to shape genome-wide patterns of genetic diversity and population structure in species characterized by widespread gene flow. Our work also offers crucial insights for stock delimitation and management of this commercially valuable species in the face of climate change.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e70027"},"PeriodicalIF":3.9,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144705897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Molecular EcologyPub Date : 2025-08-01Epub Date: 2025-07-11DOI: 10.1111/mec.70023
Rachel Berg, Gastón Aguilera, Guillermo Goyenola, Ana C Petry, Axel Meyer, Julián Torres-Dowdall
{"title":"Peripheral Budding Following Range Expansion Explains Diversity and Distribution of One-Sided Livebearing Fish.","authors":"Rachel Berg, Gastón Aguilera, Guillermo Goyenola, Ana C Petry, Axel Meyer, Julián Torres-Dowdall","doi":"10.1111/mec.70023","DOIUrl":"10.1111/mec.70023","url":null,"abstract":"<p><p>Peripheral budding occurs when populations diverge from a widespread parental population and speciate along its periphery, facilitated by the interaction of ecological and geographic barriers. This phenomenon results in species that contrast in range size and ecological tolerance and can lead to confounding phylogenies. Here we examine patterns of peripheral budding in the Jenynsia lineata species complex using a genomic approach. The J. lineata species complex is a group of live-bearing fish in South America that shows signals of peripheral budding through asymmetric range sizes, J. lineata being widespread, and with a confounding and unresolved phylogeny. Our goal was to adequately classify the J. lineata species complex, delimit species within the complex, and identify signals of introgression to better understand the underlying evolutionary patterns. We collected 85 samples from the species complex for DNA extraction and performed RAD sequencing to generate genome-wide molecular markers for phylogenetic analyses. We found evidence of six distinct genetic groups within the complex and delimited at least five species, with a new species of Jenynsia in Northern Argentina along the periphery of J. lineata. Jenynsia lineata was recovered as the most recently diverged species in our phylogeny. This placement, along with observed patterns of introgression between species, suggests peripheral budding to have facilitated speciation in the J. lineata species complex, following a range expansion of a parental J. lineata. Our results show genomic patterns associated with peripheral budding and support the utility of using peripheral budding to better understand confounding phylogenetic patterns.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e70023"},"PeriodicalIF":3.9,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12329629/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144606955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Molecular EcologyPub Date : 2025-08-01Epub Date: 2025-07-19DOI: 10.1111/mec.70028
Léna Kläy, Léo Girardin, Vincent Calvez, Florence Débarre
{"title":"The Spatial Spread and the Persistence of Gene Drives Are Affected by Demographic Feedbacks, Density Dependence and Allee Effects.","authors":"Léna Kläy, Léo Girardin, Vincent Calvez, Florence Débarre","doi":"10.1111/mec.70028","DOIUrl":"10.1111/mec.70028","url":null,"abstract":"<p><p>Homing gene drive alleles bias their own transmission by converting wild-type alleles into drive alleles. If introduced in a natural population, they might fix within a relatively small number of generations, even if they are deleterious. No engineered homing gene drive organisms have been released in the wild so far, and modelling is essential to develop a clear understanding of the potential outcomes of such releases. We use deterministic models to investigate how different demographic features affect the spatial spread of a gene drive. Building on previous work, we first consider the effect of the intrinsic population growth rate on drive spread. We confirm that including demographic dynamics can change outcomes compared to a model ignoring changes in population sizes because changes in population density can oppose the spatial spread of a drive. Secondly, we study the consequences of including an Allee effect and find that it makes a population more prone to eradication following drive spread. Finally, we investigate the effects of the fitness component on which density dependence operates (fecundity or survival) and find that it affects the speed of drive invasion in space and can accentuate the consequences of an Allee effect. These results confirm the importance of checking the robustness of model outcomes to changes in the underlying assumptions, especially if models are to be used for gene drive risk assessment.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e70028"},"PeriodicalIF":3.9,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12329647/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144666659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Molecular EcologyPub Date : 2025-08-01Epub Date: 2025-07-01DOI: 10.1111/mec.70010
Irene de Sosa, Marta Turon, Sergi Taboada, José Lorente-Sorolla, Rosa Fernández, Natasha Tilikj, Alberto Piris, Marta Novo, Patricia Álvarez Campos, Ana Riesgo
{"title":"No Mate, No Problem: Molecular Mechanisms Involved in Parthenogenesis in the Cosmopolitan Earthworm Aporrectodea trapezoides (Annelida, Clitellata).","authors":"Irene de Sosa, Marta Turon, Sergi Taboada, José Lorente-Sorolla, Rosa Fernández, Natasha Tilikj, Alberto Piris, Marta Novo, Patricia Álvarez Campos, Ana Riesgo","doi":"10.1111/mec.70010","DOIUrl":"10.1111/mec.70010","url":null,"abstract":"<p><p>Approximately, 40% of earthworm species can reproduce by parthenogenesis. This is the case for the cosmopolitan species, Aporrectodea trapezoides, although sexual forms have been described sporadically. We analyse the genotypes and microbiomes of 30 individuals from four localities where both forms appear in order to understand the evolutionary mechanisms related to parthenogenesis. In all sites, heterozygosity values were approximately 30% higher in parthenogenetic individuals. However, we detected a stronger genomic structuring due to reproduction than to the geographical setting only in the Algerian population, underpinned by 195 loci that were related to gametogenesis, symbiont-like processes, and nitrate reduction. Similarly, statistical differences in the abundance of ZOTUs were only found between the Algerian sexual and parthenogenetic earthworms, with 754 ZOTUs that included the genus Romboutsia, which is involved in the production of nitric oxide, which enhances sperm motility. In summary, significant genomic and microbiome differences were found only between sexual and parthenogenetic lineages in a single locality. We hypothesise that obligate parthenogenesis evolved early, leaving traces at the genomic and microbiome levels in the Algerian parthenogens that were the earliest splitting lineage. Such obligate parthenogenesis was lost secondarily and individuals in the Iberian sites were facultative parthenogens, with the potential to copulate and therefore erase the genomic and microbial traces of obligate parthenogenesis. Our results indicate a hybrid origin of parthenogenesis in A. trapezoides and shed light on the complex interplay between genomic, microbiome, and reproductive mechanisms in A. trapezoides.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e70010"},"PeriodicalIF":3.9,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12329633/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144525640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Molecular EcologyPub Date : 2025-08-01Epub Date: 2025-07-09DOI: 10.1111/mec.70022
Logan S Billet, Obed Hernández-Gómez, David K Skelly
{"title":"Ranavirus Epizootics and Gut Bacteriome Dysbiosis in Tadpoles: Evidence for the Anna Karenina Principle?","authors":"Logan S Billet, Obed Hernández-Gómez, David K Skelly","doi":"10.1111/mec.70022","DOIUrl":"10.1111/mec.70022","url":null,"abstract":"<p><p>The microbiome plays a critical role in animal health, yet its responses to pathogens under natural conditions remain poorly understood. We investigated gut bacterial community (bacteriome) dynamics in wood frog (Rana sylvatica [Lithobates sylvaticus]) tadpoles during natural ranavirus outbreaks to understand how pathogen-induced disturbances shape the bacteriome. Using 16S rRNA sequencing, we compared the bacteriomes of tadpoles in ponds experiencing ranavirus die-offs with those from unaffected ponds before, during and after die-offs. Ranavirus infection significantly altered gut bacteriome composition and increased variability (dispersion), consistent with the Anna Karenina principle. Tadpoles with high infection intensities exhibited reduced bacterial diversity and shifts in community structure, including enrichment of some genera that have been linked previously to antiviral immunity. The predicted functional pathway analyses revealed shifts toward carbohydrate metabolism pathways during die-offs, suggesting microbial adaptation to altered host physiology under infection stress. Some bacteriome changes were detectable even before die-offs occurred, highlighting potential early indicators of infection in the gut bacteriome. In a pond that recovered after an epizootic, we observed partial recovery of some of the bacteria that shifted in relative abundance during the die-off, a pattern that may reflect microbial resilience within hosts, selective survival of tadpoles that never developed severe infections, or a combination of both mechanisms. Our findings demonstrate that ranavirus epizootics disrupt gut bacteriomes in amphibians while simultaneously eliciting potentially adaptive microbial responses. These insights underscore the complex interplay between immunity, microbiome dynamics, and environmental conditions during disease outbreaks, highlighting opportunities for microbiome-based interventions to support amphibian conservation.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e70022"},"PeriodicalIF":3.9,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144590032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Molecular EcologyPub Date : 2025-08-01Epub Date: 2025-07-05DOI: 10.1111/mec.70009
Sofia L Mendes, Catarina Bernardo, Silvia Perea, João M Moreno, Ignacio Doadrio, Philine G D Feulner, Carla Sousa Santos, Vitor C Sousa
{"title":"Prevalent Hybridisation Between Highly Divergent Iberian Chub Species Produces Contrasting Outcomes Across Different Geographic and Time Scales.","authors":"Sofia L Mendes, Catarina Bernardo, Silvia Perea, João M Moreno, Ignacio Doadrio, Philine G D Feulner, Carla Sousa Santos, Vitor C Sousa","doi":"10.1111/mec.70009","DOIUrl":"10.1111/mec.70009","url":null,"abstract":"<p><p>Genomic data has revealed hybridisation is common in nature. Highly divergent allopatric species are often overlooked in our efforts to characterise the prevalence and consequences of hybridisation in natural systems, presumably because they are viewed as less likely to hybridise. Yet, such species are models to investigate later stages of the speciation continuum. Here, we study such a system-the Iberian chubs (Squalius spp.), a group of primary fish species with allopatric distributions across distinct environments and river catchments. Throughout their evolutionary history, the rivers inhabited by these species suffered quite dramatic changes, potentially allowing for multiple periods of isolation and secondary contact. To investigate if such a history left traces, we generated low-coverage whole-genome resequencing data for 125 individuals from eight Iberian chub species. Our results showed high levels of inter (0.44 ≤ F<sub>ST</sub> ≤ 0.88) and intra-specific (0 ≤ F<sub>ST</sub> ≤ 0.61) genetic differentiation. We uncovered four contrasting cases of potential hybridisation, spanning different geographical and time scales. First, we found evidence of ancient hybridisation on a species now inhabiting a whole river catchment. Second, we uncover recent hybridisation restricted to a localised stream, with introgression of nuclear and mitochondrial DNA. Third, we detected, at a regional scale, a case with nuclear introgression but no detectable mitochondrial DNA introgression. Finally, we uncover a case where two very distinct mitochondrial lineages persist at balanced frequencies in a putative hybrid population, despite no detectable nuclear introgression. Our findings suggest hybridisation and introgression led to assimilation or local exclusion of one or both parental species.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e70009"},"PeriodicalIF":3.9,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144566862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Molecular EcologyPub Date : 2025-08-01Epub Date: 2023-11-14DOI: 10.1111/mec.17196
Marjana Westergren, Juliette Archambeau, Marko Bajc, Rok Damjanić, Adélaïde Theraroz, Hojka Kraigher, Sylvie Oddou-Muratorio, Santiago C González-Martínez
{"title":"Low but significant evolutionary potential for growth, phenology and reproduction traits in European beech.","authors":"Marjana Westergren, Juliette Archambeau, Marko Bajc, Rok Damjanić, Adélaïde Theraroz, Hojka Kraigher, Sylvie Oddou-Muratorio, Santiago C González-Martínez","doi":"10.1111/mec.17196","DOIUrl":"10.1111/mec.17196","url":null,"abstract":"<p><p>Local survival of forest tree populations under climate change depends on existing genetic variation and their adaptability to changing environments. Responses to selection were studied in European beech (Fagus sylvatica) under field conditions. A total of 1087 adult trees, seeds, 1-year-old seedlings and established multiyear saplings were genotyped with 16 nuSSRs. Adult trees were assessed for phenotypic traits related to growth, phenology and reproduction. Parentage and paternity analyses were used to estimate effective female and male fecundity as a proxy of fitness and showed that few parents contributed to successful regeneration. Selection gradients were estimated from the relationship between traits and fecundity, while heritability and evolvability were estimated using mixed models and the breeder's equation. Larger trees bearing more fruit and early male flowering had higher total fecundity, while trees with longer growth season had lower total fecundity (directional selection). Stabilizing selection on spring phenology was found for female fecundity, highlighting the role of late frosts as a selection driver. Selection gradients for other traits varied between measurement years and the offspring cohort used to estimate parental fecundity. Compared to other studies in natural populations, we found low to moderate heritability and evolvability for most traits. Response to selection was higher for growth than for budburst, leaf senescence or reproduction traits, reflecting more consistent selection gradients across years and sex functions, and higher phenotypic variability in the population. Our study provides empirical evidence suggesting that populations of long-lived organisms such as forest trees can adapt locally, even at short-time scales.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e17196"},"PeriodicalIF":3.9,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12329638/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"92152055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Naturally Occurring Epialleles and Their Roles in Response to Climate Change in Birch.","authors":"Bowei Chen, Tianxu Zhang, Yile Guo, Lesheng Cao, Xu Zhang, Shahid Ali, Renyi Ma, Linan Xie, Jiang Wang, Gaurav Zinta, Shanwen Sun, Guifeng Liu, Qingzhu Zhang","doi":"10.1111/mec.70031","DOIUrl":"10.1111/mec.70031","url":null,"abstract":"<p><p>Epigenetics has been proposed to be an important mechanism that enables plant species to respond and adapt to environmental and climatic fluctuations and is sometimes entirely uncoupled from genetic variation. Nevertheless, the extent of this uncoupling and the contribution of epigenetics to plant responses to global climate change have not been well studied, particularly in forest trees. Here, we generated a high-quality genome assembly for Betula platyphylla, a key pioneer species in temperate and boreal forest ecosystems, one of the most sensitive areas to global warming. Extensive multi-omics sequencing of naturally white birch across the 48 provenances captured their full scope of temperate/boreal forests in Northeast China. Using a genome-wide association study (GWAS), it was shown that over 55% of differentially methylated regions (DMRs) were spontaneous, independent of genetic factors. More than 30% of the spontaneous DMRs were significantly associated with gene expression, that is, potential epialleles, which are primarily involved in metabolism and responses to abiotic stresses; and 1819 of these epialleles were significantly associated with bio-climatic variables (i.e., climatic epialleles, cEpialleles). Integrating these cEpialleles into a gradient modelling framework revealed that the natural populations of Asian white birch at high altitude/latitude might be most vulnerable to future climates. Our findings highlight the importance of integrating epigenomic and climatic data sets to forecast the adaptive capacity of a key forest species to rapid climate change.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e70031"},"PeriodicalIF":3.9,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144673541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Molecular EcologyPub Date : 2025-08-01Epub Date: 2025-07-08DOI: 10.1111/mec.70017
Tiago da Silva Ribeiro, Rodrigo Cogni
{"title":"The Way to a Generalist Herbivore's Heart Is Through Its Chemosensory Receptors: Using Multiple Approaches to Map the Genetic Basis of Adaptation in a Non-Model Organism.","authors":"Tiago da Silva Ribeiro, Rodrigo Cogni","doi":"10.1111/mec.70017","DOIUrl":"10.1111/mec.70017","url":null,"abstract":"","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e70017"},"PeriodicalIF":3.9,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12329619/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144590043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Molecular EcologyPub Date : 2025-08-01Epub Date: 2025-07-07DOI: 10.1111/mec.70014
Samarth Mathur, H Lisle Gibbs
{"title":"Genomic Evaluation of Assisted Gene Flow Options in an Endangered Rattlesnake.","authors":"Samarth Mathur, H Lisle Gibbs","doi":"10.1111/mec.70014","DOIUrl":"10.1111/mec.70014","url":null,"abstract":"<p><p>Assisted gene flow is used to counteract genetic erosion in small populations of endangered species, yet an evaluation of genetic compatibility of potential donor populations and recipient populations is rare. We developed new metrics for assessing the genetic impact of genetic augmentation based on genotype identity of functional variants between donor and recipient genomes and used these metrics to evaluate options for assisted gene flow in Eastern Massasauga rattlesnake (Sistrurus catenatus) populations in Ohio, USA. We used putatively deleterious variants and genetic variants likely under positive selection (termed 'adaptive' variants) as the two components of functional variation. For potential donor and recipient populations, we estimated three key aspects of genetic compatibility: (a) introduction of novel variants, (b) masking or unmasking of existing deleterious variants and (c) potential for outbreeding depression through disruption of local adaptation. The main impact of augmentation from diverse donor populations was to introduce novel deleterious variants and to a lesser extent novel adaptive variants into each recipient population. Both donor populations had a similar minor impact in terms of masking existing deleterious variants. Finally, only ~7% of adaptive variants show evidence for local adaptation, arguing that the negative effect of outbreeding depression would be small. These results draw attention to the importance of considering the potential impact of both deleterious and adaptive genetic variants in augmentation efforts and suggest that in the case of these endangered rattlesnakes, the net effect of proposed assisted gene flow may lead to an increase in absolute levels of mutation load.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e70014"},"PeriodicalIF":3.9,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12329626/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144574567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}