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1.
Genetica ; 153(1): 7, 2024 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-39663322

RESUMO

Due to the increase in demand for food production worldwide, the cultivation of improved varieties is used as a strategy in order to maximize production. The improved Maradol papaya variety was introduced to the Yucatan Peninsula (YP), Mexico, the Mesoamerican diversity area of papaya, in the 1990s. The domesticated and wild papaya belong to the same species (Carica papaya L.), which promotes gene flow from crops to their wild relatives, threatening the genetic diversity of wild papaya populations in the region. In this study, we used a population genomic approach to evaluate the impact of domesticated-to-wild gene flow on the genetic structure and diversity of wild papaya in the YP. We used 2054 SNP markers for 227 wild individuals from 15 collection sites and 127 domesticated individuals from 13 Maradol papaya plantations. We found, (a) the presence of individuals that may be the result of a hybridization process between wild and domesticated papaya; (b) a higher genetic diversity in the wild group (HE = 0.18) in comparison to the domesticated group (HE = 0.09); and (c) low migration rates from domesticated to wild plants (m = 0.005). The domesticated-to-wild gene flow in C. papaya can have a negative effect on the genetic diversity and adaptive potential of wild populations from this region. The conservation of crop wild relatives should be a priority since they are part of various ecological processes and are considered natural reservoirs of genetic diversity for crops.


Assuntos
Carica , Domesticação , Fluxo Gênico , Polimorfismo de Nucleotídeo Único , Carica/genética , México , Variação Genética , Produtos Agrícolas/genética , Genética Populacional
2.
Neotrop Entomol ; 54(1): 4, 2024 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-39643766

RESUMO

Genetic diversity is an important attribute of populations, essential for understanding the ecological and evolutionary processes affecting them and assessing their health status. In Hymenoptera, such as eusocial bees, colony management can influence genetic diversity in both natural and managed populations. Management can impact admixture, increasing the number of alleles due to colony displacement and decreasing the number of alleles in natural populations due to colony extraction. In this study, we analyzed genetic diversity in natural and managed colonies as well as in drone congregations of Scaptotrigona mexicana (Guérin), to assess genetic diversity, patterns of genetic structure and gene flow, and the presence of diploid males. We identified three distinct genetic groups: Northern, Central, and Southern. Although genetic differentiation and limited gene flow among genetic groups were evident, we detected significant gene flow from wild to managed populations, suggesting that natural populations can be an important reservoir of genetic diversity. The highest genetic diversity was found in the Northern group, composed of managed localities. This is likely due to the introduction of new alleles through to colony translocation. Notably, some loci exhibited more than three alleles in localities where all analyzed individuals were from the same colony, indicating possible polyandry in the species. We also detected diploid males, which suggests inbreeding and/or inefficient mechanisms for their elimination from the colony. Our results provide an initial assessment of genetic diversity in both natural and managed populations, as well as in drone congregations of S. mexicana.


Assuntos
Fluxo Gênico , Variação Genética , Animais , Abelhas/genética , Abelhas/classificação , Masculino , Golfo do México , Feminino , Alelos
3.
Mol Ecol ; 33(23): e17580, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39506895

RESUMO

The processes that restrict gene flow between populations are fundamental to speciation. Here, we develop a simple framework for studying whether divergence in morphology, climatic niche, time and space contribute to reduced gene flow among populations and species. We apply this framework to a model system involving a clade of spiny lizards (Sceloporus) occurring mostly in northeastern Mexico, which show striking variation in morphology and habitat among closely related species and populations. We developed a new time-calibrated phylogeny for the group using RADseq data from 152 individuals. This phylogeny identified 12 putative species-level clades, including at least two undescribed species. We then estimated levels of gene flow among 21 geographically adjacent pairs of species and populations. We also estimated divergence in morphological and climatic niche variables among these same pairs, along with divergence times and geographic distances. Using Bayesian generalised linear models, we found that gene flow between pairs of lineages is negatively related to divergence time and morphological divergence among them (which are uncorrelated), and not to geographic distance or climatic divergence. The framework used here can be applied to study speciation in many other organisms having genomic data but lacking direct data on reproductive isolation. We also found several other intriguing patterns in this system, including the parallel evolution of a strikingly similar montane blue-red morph from more dull-coloured desert ancestors within two different, nonsister species.


Assuntos
Teorema de Bayes , Clima , Fluxo Gênico , Especiação Genética , Lagartos , Filogenia , Animais , Lagartos/genética , Lagartos/classificação , México , Ecossistema , Modelos Genéticos , Genética Populacional
4.
Sci Rep ; 14(1): 28467, 2024 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-39557973

RESUMO

Piangua, Anadara tuberculosa, is an economically important mollusk for the human population living on the Colombian Pacific Coast. In the last years, the demand and exploitation of this mollusk have increased, putting it at risk to the point of being endangered. This research aimed to identify the genetic diversity and population structure of piangua in two localities on the Pacific Coast of Colombia. We assembled a chromosome-level genome using PacBio-Hifi and Arima sequencing. We obtained 274 scaffolds with an N50 of 45.42 Mbp, a total size of 953 Mbp, and a completeness of 91% based on BUSCO scores. The transposable elements accounted for 30.29% of the genome, and 24,317 genes were annotated. Genome-guided variant calling for 89 samples using DArT sequencing data delivered 4,825 bi-allelic SNPs, which supported genetic diversity and population structure analyses. Data showed that the piangua populations in the two localities were under expansion events more than 100k years ago. However, results also showed a reduction in genetic diversity, as evidenced by the loss of heterozygosity, which may be caused by high levels of inbreeding, probably due to a recent overexploitation. Furthermore, although we evidenced gene flow between the two localities, there is also a subtle geographical population structure between the two localities and among mangroves in one of the localities. This is the first study in Colombia that provides relevant genetic information on piangua to lay the foundations for conservation strategies.


Assuntos
Variação Genética , Colômbia , Animais , Polimorfismo de Nucleotídeo Único , Genética Populacional , Fluxo Gênico , Genoma
5.
Sci Total Environ ; 954: 176772, 2024 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-39378945

RESUMO

Climate change is altering not only the mean conditions of marine environments, but also their temporal variability and predictability. As these alterations are not uniform across seascapes, their biological effects are expected to accentuate intra-specific differences in the adaptive capacity (e.g., plasticity and evolutionary potential) of natural populations. To test this theoretical framework, we assessed the phenotypic and genetic profiles of mussel from three study sites across a multi-driver heterogeneous environmental mosaic in Chilean Patagonia. Our study reveals that temporal variability, predictability, and exposure to extreme events (low pH/low salinity), collectively, can modulate the plasticity and optimal conditions of mussels. Despite these phenotypic differences, we observed low genetic differentiation, likely resulting from significant gene flow induced by aquaculture, ultimately diminishing variation among individuals from different geographic areas. Our findings underscore how variability and predictability are essential factors shaping phenotypic diversity, even at small spatial scales. Balancing these factors could enhance species resilience and ecological success, crucial for biodiversity conservation amidst climate change.


Assuntos
Mudança Climática , Fluxo Gênico , Fenótipo , Chile , Animais , Adaptação Fisiológica , Variação Genética , Aquicultura
6.
Commun Biol ; 7(1): 1283, 2024 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-39379612

RESUMO

Despite showing the greatest primate diversity on the planet, genomic studies on Amazonian primates show very little representation in the literature. With 48 geolocalized high coverage whole genomes from wild uakari monkeys, we present the first population-level study on platyrrhines using whole genome data. In a very restricted range of the Amazon rainforest, eight uakari species (Cacajao genus) have been described and categorized into the bald and black uakari groups, based on phenotypic and ecological differences. Despite a slight habitat overlap, we show that posterior to their split 0.92 Mya, bald and black uakaris have remained independent, without gene flow. Nowadays, these two groups present distinct genetic diversity and group-specific variation linked to pathogens. We propose differing hydrology patterns and effectiveness of geographic barriers have modulated the intra-group connectivity and structure of bald and black uakari populations. With this work we have explored the effects of the Amazon rainforest's dynamism on wild primates' genetics and increased the representation of platyrrhine genomes, thus opening the door to future research on the complexity and diversity of primate genomics.


Assuntos
Genoma , Animais , Variação Genética , Floresta Úmida , Filogenia , Ecossistema , Brasil , Fluxo Gênico , Platirrinos/genética
7.
Proc Biol Sci ; 291(2030): 20240795, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39226930

RESUMO

Ever since Alfred Russel Wallace's nineteenth-century observation that related terrestrial species are often separated on opposing riverbanks, major Amazonian rivers have been recognized as key drivers of speciation. However, rivers are dynamic entities whose widths and courses may vary through time. It thus remains unknown how effective rivers are at reducing gene flow and promoting speciation over long timescales. We fit demographic models to genomic sequences to reconstruct the history of gene flow in three pairs of avian taxa fully separated by different Amazonian rivers, and whose geographic ranges do not make contact in headwater regions where rivers may cease to be barriers. Models with gene flow were best fit but still supported an initial period without any gene flow, which ranged from 187 000 to over 959 000 years, suggesting that rivers are capable of initiating speciation through long stretches of allopatric divergence. Allopatry was followed by either bursts or prolonged episodes of gene flow that retarded genomic differentiation but did not fully homogenize populations. Our results support Amazonian rivers as key barriers that promoted speciation and the build-up of species richness, but they also suggest that river barriers are often leaky, with genomic divergence accumulating slowly owing to episodes of substantial gene flow.


Assuntos
Aves , Florestas , Fluxo Gênico , Especiação Genética , Rios , Animais , Aves/genética , Brasil
8.
Heredity (Edinb) ; 133(5): 317-330, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39266673

RESUMO

Lizards in the genus Anolis comprise hundreds of species that display a wide range of phenotypic variation closely related to their environment. One example is the Guadeloupean anole (Anolis marmoratus ssp.) that display extreme phenotypic variation, primarily in adult male color and pattern, with twelve described subspecies on the archipelago. Here we examine the relationship between phenotypic and genetic divergence among five subspecies on the two main islands and test the role of geographic isolation and the environment in reducing gene flow. We also examined two offshore island populations to assess the impact of complete geographic isolation on gene flow. We analyzed color phenotypes by measuring spectral reflectance and genomic diversity using SNPs. Genetic divergence was correlated with dorsolateral head and body color phenotypes, and slope and geographic distance were nearly equivalent at explaining this divergence. There was minimal genome-wide divergence at neutral loci among phenotypically disparate subspecies on the two main islands and their differentiation is consistent with a model of divergence with gene flow. Our spatial visualization of gene flow showed an impact of environmental features consistent with a hypothesis of ecologically driven divergence. Nonetheless, subspecies on the two main islands remain interconnected by substantial gene flow and their phenotypic variation is likely maintained at selection-gene flow equilibrium by divergent selection at loci associated with their color phenotypes. Greater isolation, such as inhabiting a remote island, may be required for reducing gene flow. Our findings highlight the role of the environment, adaptation, and geographic isolation on gene flow.


Assuntos
Fluxo Gênico , Lagartos , Fenótipo , Lagartos/genética , Lagartos/classificação , Animais , Masculino , Genética Populacional , Variação Genética , Polimorfismo de Nucleotídeo Único , Meio Ambiente , Ilhas , Pigmentação/genética , Isolamento Reprodutivo , Geografia , Feminino , Guadalupe
9.
Sci Rep ; 14(1): 21081, 2024 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-39256462

RESUMO

The natural populations of the marine mussel Mytilus chilensis and the associated aquaculture industry forms a sensitive social-ecological system that relies on the released propagules for cultivation in the highly heterogeneous environment (temperature, productivity, and salinity) of northern Patagonia (42-44 °S). We assessed spatial genetic structure, signals of local adaptation, and population assignment of M. chilensis analyzing 5963 SNPs from 125 individuals across six natural populations sampled over two consecutive years along the southeast Pacific coast (39° 25' to 43° 07' S, ~ 430 km). Neutral and putatively adaptive loci revealed high genetic diversity and low genetic differentiation among populations. Of the whole dataset, less than 1% (50) of loci were identified as putatively adaptive through multiple approaches, with only 0.1% detected in by all of them, and only two loci of them were correlated with environmental variables. No evidence of Isolation by Environment (IBE) was found, albeit a slight differentiation in the southern sampling location (Yaldad). These results suggest that the genetic structure observed is primarily shaped by neutral processes with weak signals of local adaptation. Gene-flow appears to be the main evolutionary force influencing the species' population genetic structure. Because of the importance for the industry, the probability of correct assignment of individuals to their population of origin using allelic frequencies was evaluated. Analyses exhibited relatively low probabilities (< 50% for four out of six sites) of accurately assigning individuals to their geographic origin, with a limited success of SNP markers the for such purposes. Likely, species' high dispersal capacity, seed translocation, and the spill-over effect of mussel aquaculture prevents population genetic differentiation through high effective gene flow, hindering local genetic adaptation.


Assuntos
Adaptação Fisiológica , Variação Genética , Mytilus , Polimorfismo de Nucleotídeo Único , Animais , Mytilus/genética , Mytilus/fisiologia , Adaptação Fisiológica/genética , Genética Populacional , Fluxo Gênico
10.
Mol Biol Evol ; 41(9)2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39150953

RESUMO

The relative importance of genetic drift and local adaptation in facilitating speciation remains unclear. This is particularly true for seabirds, which can disperse over large geographic distances, providing opportunities for intermittent gene flow among distant colonies that span the temperature and salinity gradients of the oceans. Here, we delve into the genomic basis of adaptation and speciation of banded penguins, Galápagos (Spheniscus mendiculus), Humboldt (Spheniscus humboldti), Magellanic (Spheniscus magellanicus), and African penguins (Spheniscus demersus), by analyzing 114 genomes from the main 16 breeding colonies. We aim to identify the molecular mechanism and genomic adaptive traits that have facilitated their diversifications. Through positive selection and gene family expansion analyses, we identified candidate genes that may be related to reproductive isolation processes mediated by ecological thermal niche divergence. We recover signals of positive selection on key loci associated with spermatogenesis, especially during the recent peripatric divergence of the Galápagos penguin from the Humboldt penguin. High temperatures in tropical habitats may have favored selection on loci associated with spermatogenesis to maintain sperm viability, leading to reproductive isolation among young species. Our results suggest that genome-wide selection on loci associated with molecular pathways that underpin thermoregulation, osmoregulation, hypoxia, and social behavior appears to have been crucial in local adaptation of banded penguins. Overall, these results contribute to our understanding of how the complexity of biotic, but especially abiotic, factors, along with the high dispersal capabilities of these marine species, may promote both neutral and adaptive lineage divergence even in the presence of gene flow.


Assuntos
Seleção Genética , Spheniscidae , Animais , Spheniscidae/genética , Genômica , Especiação Genética , Fluxo Gênico , Genoma , Isolamento Reprodutivo
11.
Am J Bot ; 111(9): e16385, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39113241

RESUMO

PREMISE: Globally, barriers triggered by climatic changes have caused habitat fragmentation and population allopatric divergence. Across North America, oscillations during the Quaternary have played important roles in the distribution of wildlife. Notably, diverse plant species from the Baja California Peninsula in western North America, isolated during the Pleistocene glacial-interglacial cycles, exhibit strong genetic structure and highly concordant divergent lineages across their ranges. A representative plant genus of the peninsula is Yucca, with Y. valida having the widest range. Although a dominant species, it has an extensive distribution discontinuity between 26° N and 27° N, suggesting restricted gene flow. Moreover, historical distribution models indicate the absence of an area with suitable conditions for the species during the Last Interglacial, making it an interesting model for studying genetic divergence. METHODS: We assembled 4411 SNPs from 147 plants of Y. valida throughout its range to examine its phylogeography to identify the number of genetic lineages, quantify their genetic differentiation, reconstruct their demographic history and estimate the age of the species. RESULTS: Three allopatric lineages were identified based on the SNPs. Our analyses support that genetic drift is the driver of genetic differentiation among these lineages. We estimated an age of less than 1 million years for the common ancestor of Y. valida and its sister species. CONCLUSIONS: Habitat fragmentation caused by climatic changes, low dispersal, and an extensive geographical range gap acted as cumulative mechanisms leading to allopatric divergence in Y. valida.


Assuntos
Filogeografia , México , Polimorfismo de Nucleotídeo Único , Fluxo Gênico , Variação Genética , Filogenia , Ecossistema
12.
Ann Bot ; 134(7): 1291-1305, 2024 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-39196773

RESUMO

BACKGROUND AND AIMS: Species delimitation can be challenging when analysing recently diverged species, especially those taxonomically synonymized owing to morphological similarities. We aimed to untangle the relationships between two grassland species, Petunia guarapuavensis and Petunia scheideana, exploring the dynamics of fast divergence and addressing their species delimitation. METHODS: We used a low-coverage genome sequencing and population genomic approach to distinguish species and populations between P. guarapuavensis and P. scheideana. Our analysis focused on detecting structuration, hybridization/introgression and phylogenetic patterns. We used demographic models to support species delimitation while exploring potential phylogeographical barriers influencing gene flow. KEY RESULTS: Our findings indicated differentiation between the two species and revealed another lineage, which was phylogenetically distinct from the others and had no evidence of gene flow with them. The presence of a river acted as a phylogeographical barrier, limiting gene flow and allowing for structuration between closely related lineages. The optimal species delimitation scenario involved secondary contact between well-established lineages. CONCLUSIONS: The rapid divergence observed in these Petunia species explains the lack of significant morphological differences, because floral diagnostic traits in species sharing pollinators tend to evolve more slowly. This study highlights the complexity of species delimitation in recently diverged groups and emphasizes the importance of genomic approaches in understanding evolutionary relationships and speciation dynamics.


Assuntos
Fluxo Gênico , Especiação Genética , Pradaria , Petunia , Filogenia , Petunia/genética , Petunia/anatomia & histologia , Petunia/classificação , América do Sul , Filogeografia , Solanaceae/genética , Solanaceae/anatomia & histologia , Solanaceae/classificação
13.
Sci Rep ; 14(1): 19536, 2024 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-39174662

RESUMO

Herbicide-resistant Conyza spp. are a threat to many crops. These widespread weeds are closely related species and often cooccur. To characterize the origins of their resistance and the mechanisms underlying their spread, we assessed the genomic variation in glyphosate-resistant Conyza spp. in Brazil. Twenty populations were sampled from soybean fields across four macroregions (MRSs). A genotyping-by-sequencing study resulted in 2,998 single-nucleotide polymorphisms (SNPs) obtained for C. bonariensis (L.) and the closely related C. sumatrensis (Retz) E. Walker. Higher genomic diversity (π) and heterozygosity (HO/HE) and lower inbreeding coefficient (FIS) values were detected in populations of Conyza spp. from MRS 1 (southern) than in those from other MRSs. Strong genomic structure clustered individuals into three groups (FST = 0.22; p value = 0.000) associated with the MRSs. Thus, resistance to glyphosate originated from independent selection in different MRSs across Brazil. Our dataset supports the occurrence of intraspecific gene flow in Brazil and identified individuals of C. bonariensis that did not group within species. These findings suggest that allelic introgressions within and among species have impacted the evolution and spread of resistance to glyphosate in Conyza spp. We discuss how to mitigate new resistance cases, particularly for the released stacked traits herbicide tolerance in soybeans.


Assuntos
Conyza , Fluxo Gênico , Glycine max , Glifosato , Resistência a Herbicidas , Polimorfismo de Nucleotídeo Único , Glycine max/genética , Glycine max/efeitos dos fármacos , Resistência a Herbicidas/genética , Conyza/genética , Conyza/efeitos dos fármacos , Brasil , Herbicidas/farmacologia , Glicina/análogos & derivados , Glicina/farmacologia , Genômica/métodos
14.
Naturwissenschaften ; 111(4): 39, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39008082

RESUMO

Coastal dunes are unique habitats, threatened by human activities. In biogeographical terms, coastal dunes are habitat islands, being discrete and distinct patches of similar habitat among themselves, separated from each other by a different type of habitat. Furthermore, coastal dunes harbor endemic species, adapted to living solely in the habitats found on specific dune systems. For example, the honeypot ant Myrmecocystus baja is endemic and restricted to coastal dunes of Mexico's Baja California Pacific coast. This ecological and biogeographical scenario led to the questions whether their geographical isolation is reflected in their genetic diversity and structuring, and how their demographic history is related with the formation of the dune system habitats. To answer these questions, population genetic, isolation-with-migration, and phylogeographical analyses were carried out, based on mitochondrial and five nuclear intronic markers. Minimal gene flow was detected only between two of the dune systems sampled; otherwise, the M. baja populations were found to be isolated and genetically structured, and their divergence generally pre-dated the modern-day dune systems. It is therefore highly likely that these ants were already present in paleodunes and that each of the populations was established from founder populations as the dunes formed. These findings highlight the importance of coastal dunes for species such as the honeypot ant from Baja California, in promoting genetic differentiation.


Assuntos
Formigas , Ecossistema , Variação Genética , Animais , Formigas/genética , Formigas/classificação , México , DNA Mitocondrial/genética , Fluxo Gênico , Filogeografia
15.
Sci Rep ; 14(1): 16169, 2024 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-39003391

RESUMO

Populations in isolated and small fragments lose genetic variability very fast and are usually of conservation concern because they are at greater risk of local extinction. The largest native deer in South America, Blastocerus dichotomus (Illiger, 1815), is a Vulnerable species according to the IUCN categorization, which inhabits tropical and subtropical swampy areas. In Argentina, its presence has been restricted to four isolated fragments. Here we examine the genetic diversity and differentiation among three of them, including the three different patches that form the southernmost population, using 18 microsatellite markers genotyped by Amplicon Sequencing of DNA extracted from fecal samples. Genetic diversity was low (HE < 0.45) in all three populations studied. We found three genetic clusters compatible with the geographic location of the samples. We also found a metapopulation dynamics that involves the patches that make up the southernmost population, with evidence of a barrier to gene flow between two of them. Our results point to the creation of a corridor as a necessary and urgent management action. This is the first study, at the population level, employing microsatellite genotyping by Amplicon Sequencing with non-invasive samples in an endangered species.


Assuntos
Cervos , Fezes , Variação Genética , Repetições de Microssatélites , Animais , Cervos/genética , Repetições de Microssatélites/genética , Argentina , Genótipo , Espécies em Perigo de Extinção , Genética Populacional , Fluxo Gênico
16.
Mol Ecol ; 33(16): e17469, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39016177

RESUMO

Functional connectivity, the extent to which a landscape facilitates or impedes the dispersal of individuals across the landscape, is a key factor for the survival of species. Anthropogenic activities, such as urbanization, agriculture and roads, negatively impact functional connectivity of most species, particularly low-vagility species like lizards. Here, we examine how a landscape modified by anthropogenic activities affects the functional connectivity, at both broad and fine scales, of a widely distributed generalist lizard Sceloporus grammicus in the eastern Trans-Mexican Volcanic Belt, Mexico. We estimated for the first time the species' genetic structure, gene flow and functional connectivity in agricultural and forest zones using genomic data, a comprehensive landscape characterization and novel methods including gravity models. Our results showed not only marked genetic differentiation across the study region but also that functional connectivity is maintained for tens of kilometres despite S. grammicus low vagility. Specifically, we found that substrate and air temperature facilitated connectivity over broad and fine scales, respectively, while agricultural cover, relative humidity and slope were important for connectivity and gene flow. Contrastingly, forest cover and roads favoured (broad-scale) and limited (fine-scale) connectivity, likely associated with movement facilitated by small forest patches and with thermoregulation. Altogether, these results support that S. grammicus alternates its thermoregulatory behaviour depending on the distance travelled and the habitat environmental conditions, and that it can disperse through relatively modified landscapes, mainly using agricultural zones. The information obtained is crucial to understanding the response of lizards to current anthropogenic pressures and their potential to adapt.


Assuntos
Efeitos Antropogênicos , Fluxo Gênico , Lagartos , México , Animais , Fenômenos Geológicos , Lagartos/genética , Lagartos/fisiologia , Migração Animal , Agricultura , Genética Populacional
17.
Syst Biol ; 73(5): 758-768, 2024 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-39041315

RESUMO

Recent genomic analyses have highlighted the prevalence of speciation with gene flow in many taxa and have underscored the importance of accounting for these reticulate evolutionary processes when constructing species trees and generating parameter estimates. This is especially important for deepening our understanding of speciation in the sea where fast-moving ocean currents, expanses of deep water, and periodic episodes of sea level rise and fall act as soft and temporary allopatric barriers that facilitate both divergence and secondary contact. Under these conditions, gene flow is not expected to cease completely while contemporary distributions are expected to differ from historical ones. Here, we conduct range-wide sampling for Pederson's cleaner shrimp (Ancylomenes pedersoni), a species complex from the Greater Caribbean that contains three clearly delimited mitochondrial lineages with both allopatric and sympatric distributions. Using mtDNA barcodes and a genomic ddRADseq approach, we combine classic phylogenetic analyses with extensive topology testing and demographic modeling (10 site frequency replicates × 45 evolutionary models × 50 model simulations/replicate = 22,500 simulations) to test species boundaries and reconstruct the evolutionary history of what was expected to be a simple case study. Instead, our results indicate a history of allopatric divergence, secondary contact, introgression, and endemic hybrid speciation that we hypothesize was driven by the final closure of the Isthmus of Panama and the strengthening of the Gulf Stream Current ~3.5 Ma. The history of this species complex recovered by model-based methods that allow reticulation differs from that recovered by standard phylogenetic analyses and is unexpected given contemporary distributions. The geologically and biologically meaningful insights gained by our model selection analyses illuminate what is likely a novel pathway of species formation not previously documented that resulted from one of the most biogeographically significant events in Earth's history.


Assuntos
Especiação Genética , Filogenia , Animais , Região do Caribe , Panamá , Fluxo Gênico , Decápodes/classificação , Decápodes/genética
18.
Sci Rep ; 14(1): 15653, 2024 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-38977763

RESUMO

Despite their ancient past and high diversity, African populations are the least represented in human population genetic studies. In this study, uniparental markers (mtDNA and Y chromosome) were used to investigate the impact of sociocultural factors on the genetic diversity and inter-ethnolinguistic gene flow in the three major Nigerian groups: Hausa (n = 89), Yoruba (n = 135) and Igbo (n = 134). The results show a distinct history from the maternal and paternal perspectives. The three Nigerian groups present a similar substrate for mtDNA, but not for the Y chromosome. The two Niger-Congo groups, Yoruba and Igbo, are paternally genetically correlated with populations from the same ethnolinguistic affiliation. Meanwhile, the Hausa is paternally closer to other Afro-Asiatic populations and presented a high diversity of lineages from across Africa. When expanding the analyses to other African populations, it is observed that language did not act as a major barrier to female-mediated gene flow and that the differentiation of paternal lineages is better correlated with linguistic than geographic distances. The results obtained demonstrate the impact of patrilocality, a common and well-established practice in populations from Central-West Africa, in the preservation of the patrilineage gene pool and in the affirmation of identity between groups.


Assuntos
Cromossomos Humanos Y , DNA Mitocondrial , Fluxo Gênico , Variação Genética , Feminino , Humanos , Masculino , África Ocidental , População Negra/genética , Cromossomos Humanos Y/genética , DNA Mitocondrial/genética , Genética Populacional , Haplótipos , Herança Paterna , População Africana/genética
19.
Sci Rep ; 14(1): 15755, 2024 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-38977809

RESUMO

Guava (Psidium guajava L.) is a semi-domesticated fruit tree of moderate importance in the Neotropics, utilized for millennia due to its nutritional and medicinal benefits, but its origin of domestication remains unknown. In this study, we examine genetic diversity and population structure in 215 plants from 11 countries in Mesoamerica, the Andes, and Amazonia using 25 nuclear microsatellite loci to propose an origin of domestication. Genetic analyses reveal one gene pool in Mesoamerica (Mexico) and four in South America (Brazilian Amazonia, Peruvian Amazonia and Andes, and Colombia), indicating greater differentiation among localities, possibly due to isolation between guava populations, particularly in the Amazonian and Andean regions. Moreover, Mesoamerican populations show high genetic diversity, with moderate genetic structure due to gene flow from northern South American populations. Dispersal scenarios suggest that Brazilian Amazonia is the probable origin of guava domestication, spreading from there to the Peruvian Andes, northern South America, Central America, and Mexico. These findings present the first evidence of guava domestication in the Americas, contributing to a deeper understanding of its evolutionary history.


Assuntos
Domesticação , Variação Genética , Repetições de Microssatélites , Psidium , Psidium/genética , Repetições de Microssatélites/genética , América do Sul , Fluxo Gênico , Genética Populacional , Brasil
20.
J Med Entomol ; 61(6): 1309-1321, 2024 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-38970363

RESUMO

Population genetic structure of arthropod disease vectors provides important information on vector movement and climate or other environmental variables that influence their distribution. This information is critical for data-driven vector control. In the first comprehensive study of the genetic structure of T. dimidiata s.l. (Latreille, 1811) we focus on an area of active transmission designated as a top priority for control. We examined a high number of specimens across a broad geographic area along the border of Guatemala and El Salvador including multiple spatial scales using a high number of genome-wide markers. Measuring admixture, pairwise genetic differentiation, and relatedness, we estimated the specimens represented three genetic clusters. We found evidence of movement (migration/gene flow) across all spatial scales with more admixture among locations in El Salvador than in Guatemala. Although there was significant isolation by distance, the 2 close villages in Guatemala showed either the most or least genetic variation indicating an additional role of environmental variables. Further, we found that social factors may be influencing the genetic structure. We demonstrated the power of genomic studies with a large number of specimens across a broad geographic area. The results suggest that for effective vector control movement must be considered on multiple spatial scales along with its contributing factors.


Assuntos
Doença de Chagas , Variação Genética , Insetos Vetores , Triatoma , Animais , Triatoma/genética , Guatemala , Insetos Vetores/genética , Doença de Chagas/transmissão , El Salvador , Controle de Insetos , Distribuição Animal , Fluxo Gênico
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