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1.
Med Sci (Paris) ; 36(10): 945-948, 2020 Oct.
Artigo em Francês | MEDLINE | ID: mdl-33026341

RESUMO

More than 10 million enslaved Africans were transported to the Americas between 1500 and 1900. Recent genetic studies investigate regional African ancestry components in present-day Africa-Americans, and allow comparison with the extensive records documenting these deportations. The genetic evidence generally agrees with the historical records but brings additional insights in this dark episode of human history.


Assuntos
Afro-Americanos/genética , Pessoas Escravizadas , Escravização/história , Genética Populacional , África , Oceano Atlântico , Comércio/história , DNA Mitocondrial/análise , DNA Mitocondrial/genética , Pessoas Escravizadas/história , Fluxo Gênico/fisiologia , Variação Genética , História do Século XVI , História do Século XVII , História do Século XVIII , História do Século XIX , Humanos , Padrões de Herança/genética , Estados Unidos
2.
BMC Ecol ; 20(1): 56, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-33059667

RESUMO

BACKGROUND: Landscape genetics is an interdisciplinary field that combines tools and techniques from population genetics with the spatially explicit principles from landscape ecology. Spatial variation in genotypes is used to test hypotheses about how landscape pattern affects dispersal in a wide range of taxa. Lichens, symbiotic associations between mycobionts and photobionts, are an entity for which little is known about their dispersal mechanism. Our objective was to infer the dispersal mechanism in the semi-aquatic lichen Dermatocarpon luridum using spatial models and the spatial variation of the photobiont, Diplosphaera chodatii. We sequenced the ITS rDNA and the ß-actin gene regions of the photobiont and mapped the haplotype spatial distribution in Payuk Lake. We subdivided Payuk Lake into subpopulations and applied four spatial models based on the topography and hydrology to infer the dispersal mechanism. RESULTS: Genetic variation corresponded with the topography of the lake and the net flow of water through the waterbody. A lack of isolation-by-distance suggests high gene flow or dispersal within the lake. We infer the dispersal mechanism in D. luridum could either be by wind and/or water based on the haplotype spatial distribution of its photobiont using the ITS rDNA and ß-actin markers. CONCLUSIONS: We inferred that the dispersal mechanism could be either wind and/or water dispersed due to the conflicting interpretations of our landscape hypotheses. This is the first study to use spatial modelling to infer dispersal in semi-aquatic lichens. The results of this study may help to understand lichen dispersal within aquatic landscapes, which can have implications in the conservation of rare or threatened lichens.


Assuntos
Líquens , Fluxo Gênico , Genética Populacional , Genótipo , Líquens/genética , Simbiose
3.
PLoS One ; 15(10): e0238729, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33048933

RESUMO

The Amazonian and Atlantic Forest share several organisms that are currently isolated but were continuously distributed during the Quaternary period. As both biomes are under different climatic regimes, paleoclimatic events may have modulated species' niches due to a lack of gene flow and imposing divergent selection pressure. Here, we assessed patterns of ecological niche overlap in 37 species of birds with disjunct ranges between the Amazonian and Brazilian Atlantic Forests. We performed niche overlap analysis and ecological niche modeling using four machine-learning algorithms to evaluate whether species' ecological niches evolved or remained conserved after the past South American biogeographic events. We found a low niche overlap among the same species populations in the two biomes. However, niche similarity tests showed that, for half of the species, the overlap was higher than the ones generated by our null models. These results lead us to conclude that niche conservatism was not enough to avoid ecological differentiation among species even though detected in many species. In sum, our results support the role of climatic changes in late-Pleistocene-that isolated Amazon and the Atlantic Forest-as a driving force of ecological differences among the same species populations and potential mechanism of current diversification in both regions.


Assuntos
Evolução Biológica , Aves/classificação , Aves/genética , Ecossistema , Floresta Úmida , Animais , Biodiversidade , Brasil , Mudança Climática/história , Fluxo Gênico , Especiação Genética , História Antiga , Filogeografia , Dinâmica Populacional/história
4.
Zootaxa ; 4789(2): zootaxa.4789.2.10, 2020 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-33056440

RESUMO

The Changeable Hawk-Eagle Nisaetus cirrhatus complex is represented by two taxa in mainland India: N. c. cirrhatus in the northern plains and peninsula and N. c. limnaeetus in the Himalayan foothills. Traditionally these taxa have been regarded as subspecies of one species, but recently they have been proposed to be different species. Here, we use an integrative taxonomic approach based on considerations of plumage, biometrics, genetics and vocalizations. Several plumage characters are significantly different between the two taxa, but crest length was the only one of 56 characters that was diagnostically different, with no overlap. About 30% of the birds had intermediate crest lengths, suggesting that they are hybrids or backcrosses, as also supported by the microsatellite results. PCAs of adult plumage show many intermediate individuals, irrespective of whether these birds were collected near a putative contact zone. There is restricted gene flow between the two taxa, presumably as a result of their largely allopatric distributions. On current knowledge, reproductive isolation appears to be weak at best, and we therefore recommend continuing to regard limnaeetus and cirrhatus as conspecific.


Assuntos
Águias , Falcões , Animais , Fluxo Gênico , Índia , Repetições de Microssatélites
5.
Zootaxa ; 4801(1): zootaxa.4801.1.7, 2020 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-33056676

RESUMO

In this article we present a comparative study between the three subspecies of Laemostenus (Antisphodrus) cazorlensis (Mateu, 1953) (Coleoptera, Carabidae), a representative carabid of the cave fauna of Jaén and Albacete (southern Spain). The aim of this work was to examine the validity of the characters typically used to distinguish the subspecies L. (A.) c. cazorlensis (Mateu, 1953), L. (A.) c. divergens (Mateu, 1953) and L. (A.) c. seguranus (Vives Vives, 1982) and check if they support the actual subspecific classification. For this purpose, a morphometric study of the pronotum and a morphological study of the male and female genitalia were carried out on 161 individuals of the three subspecies from the different geographic territories within the known distribution range of the species. An ANOVA analysis was run to support the results of the morphometric study developed with the total of studied samples. The results suggest that none of the studied characters can be used to characterize any of the subspecific taxa. Besides, the karstic profile of the ground in where this species inhabits could facilitate the genetic flow between its populations, so it is possible that they are not completely isolated. We conclude that the observable differences between individuals of Laemostenus (Antisphodrus) cazorlensis for the studied characters reflect intraspecific variability, and do not support a subspecific classification of the species. We propose the synonymization of the two non-typical subspecies of Laemostenus (Antisphodrus) cazorlensis with the typical one and, therefore, with the specific taxa.


Assuntos
Besouros , Animais , Cavernas , Feminino , Fluxo Gênico , Masculino
6.
PLoS One ; 15(9): e0239123, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32925982

RESUMO

Cultivated diversity is considered an insurance against major climatic variability. However, since the 1980s, several studies have shown that climate variability and agricultural changes may already have locally eroded crop genetic diversity. We studied pearl millet diversity in Senegal through a comparison of pearl millet landraces collected 40 years apart. We found that more than 20% of villages visited in 1976 had stopped growing pearl millet. Despite this, its overall genetic diversity has been maintained but differentiation between early- and late-flowering accessions has been reduced. We also found stronger crop-to-wild gene flow than wild-to-crop gene flow and that wild-to-crop gene flow was weaker in 2016 than in 1976. In conclusion, our results highlight genetic homogenization in Senegal. This homogenization within cultivated pearl millet and between wild and cultivated forms is a key factor in genetic erosion and it is often overlooked. Improved assessment and conservation strategies are needed to promote and conserve both wild and cultivated pearl millet diversity.


Assuntos
Produção Agrícola/tendências , Produtos Agrícolas/genética , Evolução Molecular , Variação Genética , Pennisetum/genética , Conservação dos Recursos Naturais , Produção Agrícola/história , Produção Agrícola/estatística & dados numéricos , DNA de Plantas/genética , DNA de Plantas/isolamento & purificação , Flores/crescimento & desenvolvimento , Fluxo Gênico , História do Século XX , História do Século XXI , Senegal
7.
Nature ; 585(7825): 390-396, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32939067

RESUMO

The maritime expansion of Scandinavian populations during the Viking Age (about AD 750-1050) was a far-flung transformation in world history1,2. Here we sequenced the genomes of 442 humans from archaeological sites across Europe and Greenland (to a median depth of about 1×) to understand the global influence of this expansion. We find the Viking period involved gene flow into Scandinavia from the south and east. We observe genetic structure within Scandinavia, with diversity hotspots in the south and restricted gene flow within Scandinavia. We find evidence for a major influx of Danish ancestry into England; a Swedish influx into the Baltic; and Norwegian influx into Ireland, Iceland and Greenland. Additionally, we see substantial ancestry from elsewhere in Europe entering Scandinavia during the Viking Age. Our ancient DNA analysis also revealed that a Viking expedition included close family members. By comparing with modern populations, we find that pigmentation-associated loci have undergone strong population differentiation during the past millennium, and trace positively selected loci-including the lactase-persistence allele of LCT and alleles of ANKA that are associated with the immune response-in detail. We conclude that the Viking diaspora was characterized by substantial transregional engagement: distinct populations influenced the genomic makeup of different regions of Europe, and Scandinavia experienced increased contact with the rest of the continent.


Assuntos
Fluxo Gênico/genética , Genética Populacional , Genoma Humano/genética , Genômica , Migração Humana/história , Alelos , Conjuntos de Dados como Assunto , Inglaterra , Evolução Molecular , Groenlândia , História Medieval , Humanos , Imunidade/genética , Irlanda , Lactase/genética , Lactase/metabolismo , Masculino , Países Escandinavos e Nórdicos , Seleção Genética , Análise Espaço-Temporal , Adulto Jovem
8.
Proc Biol Sci ; 287(1934): 20200875, 2020 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-32900318

RESUMO

Recently diverged taxa with contrasting phenotypes offer opportunities for unravelling the genetic basis of phenotypic variation in nature. Horseshoe bats are a speciose group that exhibit a derived form of high-duty cycle echolocation in which the inner ear is finely tuned to echoes of the narrowband call frequency. Here, by focusing on three recently diverged subspecies of the intermediate horseshoe bat (Rhinolophus affinis) that display divergent echolocation call frequencies, we aim to identify candidate loci putatively involved in hearing frequency variation. We used de novo transcriptome sequencing of two mainland taxa (himalayanus and macrurus) and one island taxon (hainanus) to compare expression profiles of thousands of genes. By comparing taxa with divergent call frequencies (around 15 kHz difference), we identified 252 differentially expressed genes, of which six have been shown to be involved in hearing or deafness in human/mouse. To obtain further validation of these results, we applied quantitative reverse transcription-PCR to the candidate gene FBXL15 and found a broad association between the level of expression and call frequency across taxa. The genes identified here represent strong candidate loci associated with hearing frequency variation in bats.


Assuntos
Quirópteros/genética , Ecolocação/fisiologia , Transcriptoma , Animais , Fluxo Gênico , Audição , Filogenia
9.
Nat Commun ; 11(1): 4763, 2020 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-32958765

RESUMO

Many animal species remain separate not because their individuals fail to produce viable hybrids but because they "choose" not to mate. However, we still know very little of the genetic mechanisms underlying changes in these mate preference behaviours. Heliconius butterflies display bright warning patterns, which they also use to recognize conspecifics. Here, we couple QTL for divergence in visual preference behaviours with population genomic and gene expression analyses of neural tissue (central brain, optic lobes and ommatidia) across development in two sympatric Heliconius species. Within a region containing 200 genes, we identify five genes that are strongly associated with divergent visual preferences. Three of these have previously been implicated in key components of neural signalling (specifically an ionotropic glutamate receptor and two regucalcins), and overall our candidates suggest shifts in behaviour involve changes in visual integration or processing. This would allow preference evolution without altering perception of the wider environment.


Assuntos
Borboletas/fisiologia , Genes de Insetos , Especiação Genética , Preferência de Acasalamento Animal , Percepção Visual/genética , Animais , Borboletas/genética , Feminino , Regulação da Expressão Gênica , Fluxo Gênico , Genes de Insetos/genética , Genoma de Inseto/genética , Masculino , Mutação , Locos de Características Quantitativas , Especificidade da Espécie , Simpatria , Asas de Animais
10.
Nat Commun ; 11(1): 4556, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32917883

RESUMO

Previous genetic studies have identified local population structure within the Netherlands; however their resolution is limited by use of unlinked markers and absence of external reference data. Here we apply advanced haplotype sharing methods (ChromoPainter/fineSTRUCTURE) to study fine-grained population genetic structure and demographic change across the Netherlands using genome-wide single nucleotide polymorphism data (1,626 individuals) with associated geography (1,422 individuals). We identify 40 haplotypic clusters exhibiting strong north/south variation and fine-scale differentiation within provinces. Clustering is tied to country-wide ancestry gradients from neighbouring lands and to locally restricted gene flow across major Dutch rivers. North-south structure is temporally stable, with west-east differentiation more transient, potentially influenced by migrations during the middle ages. Despite superexponential population growth, regional demographic estimates reveal population crashes contemporaneous with the Black Death. Within Dutch and international data, GWAS incorporating fine-grained haplotypic covariates are less confounded than standard methods.


Assuntos
Grupos Étnicos/genética , Genética Populacional , Estudo de Associação Genômica Ampla , Estudos de Casos e Controles , Análise por Conglomerados , Emigração e Imigração , Grupo com Ancestrais do Continente Europeu/genética , Fluxo Gênico , Variação Genética/genética , Genoma , Geografia , Haplótipos , Humanos , Pessoa de Meia-Idade , Modelos Genéticos , Países Baixos , Polimorfismo de Nucleotídeo Único
11.
An Acad Bras Cienc ; 92(suppl 2): e20180532, 2020 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-32901674

RESUMO

The restinga is a threatened Brazilian ecosystem and a highly heterogeneous environment. This work aimed to evaluate demographic and genetic aspects of Varronia curassavica and whether environmental heterogeneity can influence the studied population parameters. Three annual evaluations were carried out in an area of restinga in Florianópolis-SC, Brazil. Demographic data were analyzed using descriptive statistics, and the spatial distribution pattern was calculated by Ripley's K-function and correlated with environmental characteristics. To characterize diversity and genetic structure, eight microsatellite markers were used. This work demonstrated that variations in the distribution of individuals and genotypes can be related to specific environments. Dry lowlands were environments favorable to population development, and flooded lowland and mobile dunes were unfavorable. The fixation indices were distinct between environments, evidencing a tendency toward preferential crosses in favor of heterozygotes. We found absence of spatial genetic structure, indicating that genotypes are randomly distributed and that gene flow may be related to such genetic factors as the presence of autoincompatibility mechanisms. This diversity of environments contributed to the aggregate distribution and is relevant for the maintenance of demographic and genetic processes of the species in restingas, and this aspect should be considered for in situ conservation.


Assuntos
Ecossistema , Brasil , Demografia , Fluxo Gênico , Repetições de Microssatélites
12.
Acta amaz ; 50(3): 204-212, jul. - set. 2020.
Artigo em Inglês | LILACS | ID: biblio-1118824

RESUMO

Rosewood, Aniba rosaeodora is an endangered species in Amazon forests and its natural stands have been heavily depleted due to over-exploitation for the cosmetic industry. This study aimed to investigate the genetic diversity and population structure of 90 rosewood accessions from eight localities in the Peruvian Amazon through 11 Inter Simple Sequence Repeats (ISSR) primers. The ISSR primers produced a sum of 378 bands, of which 375 (99.2%) were polymorphic, with an average polymorphism information content (PIC) value of 0.774. The mean effective number of alleles (Ne), Shannon informative index (I), gene diversity (He) and total gene diversity (Ht) were 1.485, 0.294, 0.453 and 0.252, respectively. Analysis of molecular variance (AMOVA) showed the presence of maximum variability within populations (88%). The Structure algorithm, neighbor joining and principal coordinate analysis (PCoA) grouped the 90 rosewood accessions into three main populations (A, B and C). Diversity indices at the inter-population level revealed a greater genetic diversity in population A, due to higher gene flow. The neighbor-joining analysis grouped populations A and B, while population C was found to be divergent at the inter population level. We concluded that population A reflects higher genetic diversity and should be prioritized for future management and conservation plans. (AU)


Assuntos
Variação Genética , Espécies em Perigo de Extinção , Fluxo Gênico
13.
BMC Evol Biol ; 20(1): 110, 2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-32847507

RESUMO

BACKGROUND: Island systems offer excellent opportunities for studying the evolutionary histories of species by virtue of their restricted size and easily identifiable barriers to gene flow. However, most studies investigating evolutionary patterns and processes shaping biotic diversification have focused on more recent (emergent) rather than ancient oceanic archipelagos. Here, we focus on the granitic islands of the Seychelles, which are unusual among island systems because they have been isolated for a long time and are home to a monophyletic radiation of caecilian amphibians that has been separated from its extant sister lineage for ca. 65-62 Ma. We selected the most widespread Seychelles caecilian species, Hypogeophis rostratus, to investigate intraspecific morphological and genetic (mitochondrial and nuclear) variation across the archipelago (782 samples from nine islands) to identify patterns and test processes that shaped their evolutionary history within the Seychelles. RESULTS: Overall a signal of strong geographic structuring with distinct northern- and southern-island clusters were identified across all datasets. We suggest that these distinct groups have been isolated for ca. 1.26 Ma years without subsequent migration between them. Populations from the somewhat geographically isolated island of Frégate showed contrasting relationships to other islands based on genetic and morphological data, clustering alternatively with northern-island (genetic) and southern-island (morphological) populations. CONCLUSIONS: Although variation in H. rostratus across the Seychelles is explained more by isolation-by-distance than by adaptation, the genetic-morphological incongruence for affinities of Frégate H. rostratus might be caused by local adaptation over-riding the signal from their vicariant history. Our findings highlight the need of integrative approaches to investigate fine-scale geographic structuring to uncover underlying diversity and to better understand evolutionary processes on ancient, continental islands.


Assuntos
Anfíbios , Fluxo Gênico , Variação Genética , Genética Populacional , Anfíbios/genética , Animais , Evolução Biológica , Ilhas , Filogenia , Isolamento Reprodutivo , Seicheles
14.
Nat Commun ; 11(1): 3868, 2020 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-32747648

RESUMO

Archaeological research documents major technological shifts among people who have lived in the southern tip of South America (South Patagonia) during the last thirteen millennia, including the development of marine-based economies and changes in tools and raw materials. It has been proposed that movements of people spreading culture and technology propelled some of these shifts, but these hypotheses have not been tested with ancient DNA. Here we report genome-wide data from 20 ancient individuals, and co-analyze it with previously reported data. We reveal that immigration does not explain the appearance of marine adaptations in South Patagonia. We describe partial genetic continuity since ~6600 BP and two later gene flows correlated with technological changes: one between 4700-2000 BP that affected primarily marine-based groups, and a later one impacting all <2000 BP groups. From ~2200-1200 BP, mixture among neighbors resulted in a cline correlated to geographic ordering along the coast.


Assuntos
DNA Antigo/análise , Fósseis , Fluxo Gênico , Genoma Humano/genética , Migração Humana , Arqueologia/métodos , Argentina , Osso e Ossos/metabolismo , Chile , DNA Mitocondrial/classificação , DNA Mitocondrial/genética , Variação Genética , Geografia , Humanos , Filogenia , Datação Radiométrica/métodos , Análise de Sequência de DNA/métodos , Dente/metabolismo
15.
PLoS Genet ; 16(8): e1008895, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32760067

RESUMO

The sequencing of Neanderthal and Denisovan genomes has yielded many new insights about interbreeding events between extinct hominins and the ancestors of modern humans. While much attention has been paid to the relatively recent gene flow from Neanderthals and Denisovans into modern humans, other instances of introgression leave more subtle genomic evidence and have received less attention. Here, we present a major extension of the ARGweaver algorithm, called ARGweaver-D, which can infer local genetic relationships under a user-defined demographic model that includes population splits and migration events. This Bayesian algorithm probabilistically samples ancestral recombination graphs (ARGs) that specify not only tree topologies and branch lengths along the genome, but also indicate migrant lineages. The sampled ARGs can therefore be parsed to produce probabilities of introgression along the genome. We show that this method is well powered to detect the archaic migration into modern humans, even with only a few samples. We then show that the method can also detect introgressed regions stemming from older migration events, or from unsampled populations. We apply it to human, Neanderthal, and Denisovan genomes, looking for signatures of older proposed migration events, including ancient humans into Neanderthal, and unknown archaic hominins into Denisovans. We identify 3% of the Neanderthal genome that is putatively introgressed from ancient humans, and estimate that the gene flow occurred between 200-300kya. We find no convincing evidence that negative selection acted against these regions. Finally, we predict that 1% of the Denisovan genome was introgressed from an unsequenced, but highly diverged, archaic hominin ancestor. About 15% of these "super-archaic" regions-comprising at least about 4Mb-were, in turn, introgressed into modern humans and continue to exist in the genomes of people alive today.


Assuntos
Fluxo Gênico , Modelos Genéticos , Homem de Neandertal/genética , População/genética , Recombinação Genética , Animais , Evolução Molecular , Migração Humana , Humanos
16.
Proc Biol Sci ; 287(1932): 20201459, 2020 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-32752983

RESUMO

Hybridization events are not uncommon in marine environments where physical barriers are attenuated. Studies of coral reef taxa have suggested that hybridization predominantly occurs between parapatric species distributed along biogeographic suture zones. By contrast, little is known about the extent of sympatric hybridization on coral reefs, despite the large amount of biogeographic overlap shared by many coral reef species. Here, we investigate if the propensity for hybridization along suture zones represents a general phenomenon among coral reef fishes, by focusing on the marine angelfishes (family Pomacanthidae). Although hybridization has been reported for this family, it has not been thoroughly surveyed, with more recent hybridization studies focusing instead on closely related species from a population genetics perspective. We provide a comprehensive survey of hybridization among the Pomacanthidae, characterize the upper limits of genetic divergences between hybridizing species and investigate the occurrence of sympatric hybridization within this group. We report the occurrence of hybridization involving 42 species (48% of the family) from all but one genus of the Pomacanthidae. Our results indicate that the marine angelfishes are among the groups of coral reef fishes with the highest incidences of hybridization, not only between sympatric species, but also between deeply divergent lineages.


Assuntos
Peixes/fisiologia , Hibridização Genética , Simpatria , Animais , Recifes de Corais , Fluxo Gênico , Genética Populacional
17.
PLoS One ; 15(8): e0236509, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785243

RESUMO

Knowledge about population genetic structure and dispersal capabilities is important for the development of targeted management strategies for agricultural pest species. The apple fruit moth, Argyresthia conjugella (Lepidoptera, Yponomeutidae), is a pre-dispersal seed predator. Larvae feed on rowanberries (Sorbus aucuparia), and when rowanberry seed production is low (i.e., inter-masting), the moth switches from laying eggs in rowanberries to apples (Malus domestica), resulting in devastating losses in apple crops. Using genetic methods, we investigated if this small moth expresses any local genetic structure, or alternatively if gene flow may be high within the Scandinavian Peninsula (~850.000 km2, 55o - 69o N). Genetic diversity was found to be high (n = 669, mean He = 0.71). For three out of ten tetranucleotide STRs, we detected heterozygote deficiency caused by null alleles, but tests showed little impact on the overall results. Genetic differentiation between the 28 sampling locations was very low (average FST = 0.016, P < 0.000). Surprisingly, we found that all individuals could be assigned to one of two non-geographic genetic clusters, and that a third, geographic cluster was found to be associated with 30% of the sampling locations, with weak but significant signals of isolation-by-distance. Conclusively, our findings suggest wind-aided dispersal and spatial synchrony of both sexes of the apple fruit moth over large areas and across very different climatic zones. We speculate that the species may recently have had two separate genetic origins caused by a genetic bottleneck after inter-masting, followed by rapid dispersal and homogenization of the gene pool across the landscape. We suggest further investigations of spatial genetic similarities and differences of the apple fruit moth at larger geographical scales, through life-stages, across inter-masting, and during attacks by the parasitoid wasp (Microgaster politus).


Assuntos
Genética Populacional , Repetições de Microssatélites/genética , Mariposas/genética , Oviposição/fisiologia , Animais , Frutas/genética , Fluxo Gênico , Variação Genética , Larva/genética , Larva/crescimento & desenvolvimento , Malus/crescimento & desenvolvimento , Malus/parasitologia , Mariposas/patogenicidade , Mariposas/fisiologia , Oviposição/genética , Dispersão de Sementes/genética , Sorbus/genética , Sorbus/parasitologia
18.
PLoS One ; 15(8): e0237546, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32790795

RESUMO

Due to substantial population decline, the Korean orchid P. scolopendrifolia is considered endangered and highly threatened. Like many endangered species, it is vulnerable to biological and anthropogenic threats that can lead to the loss of genetic diversity and, ultimately, extinction. Therefore, the assessment of genetic diversity and population genetic structure is imperative for conservation. In this study, we newly developed 15 polymorphic microsatellite markers. Analyses of genetic diversity and population genetic structure that included 182 samples from 11 populations were conducted using microsatellite markers and four noncoding regions of chloroplast DNA. Our study revealed a relatively low level of genetic diversity (Ho = 0.529, He = 0.356), albeit harboring with private alleles based on microsatellite genotyping data, and high haplotype diversities based on chloroplast DNA sequences data. The results of STRUCTURE and PCoA based on microsatellite genotyping data showed population differentiations. An AMOVA based on chloroplast DNA sequence data further corroborated these conclusions, indicating about 70% of variations found among populations. Low genetic diversity and divergence among the population might have been caused by factors, such as asexual reproduction, demographic events (bottleneck and population expansion), geographic isolation, and low gene flow. The development and implication of conservation strategies and management of P. scolopendrifolia are proposed based on these results.


Assuntos
DNA de Cloroplastos/análise , Espécies em Perigo de Extinção/estatística & dados numéricos , Variação Genética , Genética Populacional , Repetições de Microssatélites , Orchidaceae/genética , Fluxo Gênico , Haplótipos , República da Coreia
19.
BMC Evol Biol ; 20(1): 100, 2020 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-32778052

RESUMO

BACKGROUND: Under the threat of climate change populations can disperse, acclimatise or evolve in order to avoid fitness loss. In light of this, it is important to understand neutral gene flow patterns as a measure of dispersal potential, but also adaptive genetic variation as a measure of evolutionary potential. In order to assess genetic variation and how this relates to environment in the honeycomb worm (Sabellaria alveolata (L.)), a reef-building polychaete that supports high biodiversity, we carried out RAD sequencing using individuals from along its complete latitudinal range. Patterns of neutral population genetic structure were compared to larval dispersal as predicted by ocean circulation modelling, and outlier analyses and genotype-environment association tests were used to attempt to identify loci under selection in relation to local temperature data. RESULTS: We genotyped 482 filtered SNPs, from 68 individuals across nine sites, 27 of which were identified as outliers using BAYESCAN and ARLEQUIN. All outlier loci were potentially under balancing selection, despite previous evidence of local adaptation in the system. Limited gene flow was observed among reef-sites (FST = 0.28 ± 0.10), in line with the low dispersal potential identified by the larval dispersal models. The North Atlantic reef emerged as a distinct population and this was linked to high local larval retention and the effect of the North Atlantic Current on dispersal. CONCLUSIONS: As an isolated population, with limited potential for natural genetic or demographic augmentation from other reefs, the North Atlantic site warrants conservation attention in order to preserve not only this species, but above all the crucial functional ecological roles that are associated with their bioconstructions. Our study highlights the utility of using seascape genomics to identify populations of conservation concern.


Assuntos
Alveolados/genética , Genética Populacional , Genômica , Adaptação Biológica , Animais , Recifes de Corais , Fluxo Gênico
20.
Nature ; 583(7817): 572-577, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32641827

RESUMO

The possibility of voyaging contact between prehistoric Polynesian and Native American populations has long intrigued researchers. Proponents have pointed to the existence of New World crops, such as the sweet potato and bottle gourd, in the Polynesian archaeological record, but nowhere else outside the pre-Columbian Americas1-6, while critics have argued that these botanical dispersals need not have been human mediated7. The Norwegian explorer Thor Heyerdahl controversially suggested that prehistoric South American populations had an important role in the settlement of east Polynesia and particularly of Easter Island (Rapa Nui)2. Several limited molecular genetic studies have reached opposing conclusions, and the possibility continues to be as hotly contested today as it was when first suggested8-12. Here we analyse genome-wide variation in individuals from islands across Polynesia for signs of Native American admixture, analysing 807 individuals from 17 island populations and 15 Pacific coast Native American groups. We find conclusive evidence for prehistoric contact of Polynesian individuals with Native American individuals (around AD 1200) contemporaneous with the settlement of remote Oceania13-15. Our analyses suggest strongly that a single contact event occurred in eastern Polynesia, before the settlement of Rapa Nui, between Polynesian individuals and a Native American group most closely related to the indigenous inhabitants of present-day Colombia.


Assuntos
Fluxo Gênico/genética , Genoma Humano/genética , Migração Humana/história , Índios Centro-Americanos/genética , Índios Sul-Americanos/genética , Ilhas , Grupo com Ancestrais Oceânicos/genética , América Central/etnologia , Colômbia/etnologia , Europa (Continente)/etnologia , Genética Populacional , História Medieval , Humanos , Polimorfismo de Nucleotídeo Único/genética , Polinésia , América do Sul/etnologia , Fatores de Tempo
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