scholarly journals Caribbean golden orbweaving spiders maintain gene flow with North America

2018 ◽  
Author(s):  
Klemen Čandek ◽  
Ingi Agnarsson ◽  
Greta J. Binford ◽  
Matjaž Kuntner
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
North America ◽  
Population Genetic ◽  
Single Species ◽  
Haplotype Network ◽  
Dispersal Ability ◽  
Dispersal Potential ◽  
The Caribbean ◽  
Globally Distributed

AbstractThe Caribbean archipelago offers one of the best natural arenas for testing biogeographic hypotheses. The intermediate dispersal model of biogeography (IDM) predicts variation in species richness among lineages on islands to relate to their dispersal potential. To test this model, one would need background knowledge of dispersal potential of lineages, which has been problematic as evidenced by our prior biogeographic work on the Caribbean tetragnathid spiders. In order to investigate the biogeographic imprint of an excellent disperser, we study the American Trichonephila, a nephilid genus that contains globally distributed species known to overcome long, overwater distances. Our results reveal that the American T. clavipes shows a phylogenetic and population genetic structure consistent with a single species over the Caribbean, but not over the entire Americas. Haplotype network suggests that populations maintain lively gene flow between the Caribbean and North America. Combined with prior evidence from spider genera of different dispersal ability, these patterns coming from an excellent disperser (Trichonephila) that is species poor and of a relatively homogenous genetic structure, support the IDM predictions.

scholarly journals High levels of gene flow and low population genetic structure related to high dispersal potential of a tropical marine angiosperm

2009 ◽  
Vol 390 ◽  
pp. 67-77 ◽  
Author(s):  
JK van Dijk ◽  
BI van Tussenbroek ◽  
K Jiménez-Durán ◽  
GJ Márquez-Guzmán ◽  
J Ouborg
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
High Dispersal ◽  
Dispersal Potential ◽  
Marine Angiosperm

scholarly journals The influence of gene flow and drift on genetic and phenotypic divergence in two species of Zosterops in Vanuatu

2010 ◽  
Vol 365 (1543) ◽  
pp. 1077-1092 ◽  
Author(s):  
Sonya M. Clegg ◽  
Albert B. Phillimore
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Bird Species ◽  
Dispersal Ability ◽  
Phenotypic Divergence ◽  
Genetic Patterns ◽  
Changing Patterns ◽  
Regional Population

Colonization of an archipelago sets the stage for adaptive radiation. However, some archipelagos are home to spectacular radiations, while others have much lower levels of diversification. The amount of gene flow among allopatric populations is one factor proposed to contribute to this variation. In island colonizing birds, selection for reduced dispersal ability is predicted to produce changing patterns of regional population genetic structure as gene flow-dominated systems give way to drift-mediated divergence. If this transition is important in facilitating phenotypic divergence, levels of genetic and phenotypic divergence should be associated. We consider population genetic structure and phenotypic divergence among two co-distributed, congeneric (Genus: Zosterops ) bird species inhabiting the Vanuatu archipelago. The more recent colonist, Z. lateralis , exhibits genetic patterns consistent with a strong influence of distance-mediated gene flow. However, complex patterns of asymmetrical gene flow indicate variation in dispersal ability or inclination among populations. The endemic species, Z. flavifrons , shows only a partial transition towards a drift-mediated system, despite a long evolutionary history on the archipelago. We find no strong evidence that gene flow constrains phenotypic divergence in either species, suggesting that levels of inter-island gene flow do not explain the absence of a radiation across this archipelago.

scholarly journals Global biogeography of Tetragnatha spiders reveals multiple colonization of the Caribbean

2018 ◽  
Author(s):  
Klemen Čandek ◽  
Ingi Agnarsson ◽  
Greta J. Binford ◽  
Matjaž Kuntner
Keyword(s):  
Dispersal Ability ◽  
Land Bridge ◽  
Biogeographic History ◽  
Putative Species ◽  
Dispersal Potential ◽  
The Caribbean ◽  
Low Levels ◽  
Richness Patterns ◽  
Globally Distributed ◽  
High Diversity

AbstractOrganismal variation in dispersal ability can directly affect levels of gene flow amongst populations, therefore importantly shaping species distributions and species richness patterns. The intermediate dispersal model of biogeography (IDM) predicts that in island systems, species diversity of those lineages with an intermediate dispersal potential is the highest. We broadly test this prediction, focusing on ‘four-jawed spiders’ (genus Tetragnatha) of the Caribbean archipelago. First, we report on original sampling of this globally distributed genus with numerous widespread as well as endemic species. We then reconstruct multiple Tetragnatha phylogenies from roughly 300 individuals delineated into 54 putative species. Our results support the monophyly of the four-jawed spiders but reject the monophyly of those lineages that reach the Caribbean, where we find low levels of endemism yet high diversity within Tetragnatha. The chronogram detects a potential early overwater colonization of the Caribbean, and in combination with reconstructed biogeographic history, refutes the possibility of ancient vicariant origins of Caribbean Tetragnatha as well as the GAARlandia land-bridge scenario. Instead, biogeographic results hypothesize multiple colonization events to, and from the Caribbean since mid-Eocene to late-Miocene. Tetragnatha seems unique among the arachnids explored so far in comprising some species that are excellent dispersers, and others that are not, perhaps having secondarily lost this dispersal propensity. A direct test of the IDM would require consideration of three categories of dispersers. However, four-jawed spiders do not fit one of these three a priori definitions, but rather represent a more complex combination of attributes of a ‘dynamic disperser’.

Genetic variation in Trillium erectum (Melanthiaceae), a widespread forest herb in eastern North America

2004 ◽  
Vol 82 (3) ◽  
pp. 316-321 ◽  
Author(s):  
Steven R Griffin ◽  
Spencer CH Barrett
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Gene Flow ◽  
Genetic Structure ◽  
North America ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Eastern North America ◽  
Mixed Mating ◽  
Allozyme Loci

Trillium erectum L. is an insect-pollinated understory herb widespread in forests of eastern North America. Marker gene studies indicate that the species has a mixed mating system, but aspects of population genetic structure have not been investigated. Using 10 allozyme loci, we measured genetic variation within and among 23 populations sampled from throughout the species' range. Overall, T. erectum displayed moderate levels of genetic diversity in comparison with other herbaceous plants. The percentage of loci that were polymorphic was 52%, with average values (±SE) of 1.20 ± 0.02, 0.08 ± 0.01, and 0.13 ± 0.01 for the number of alleles per locus (A), observed heterozygosity (Ho), and expected heterozygosity (He), respectively. There was evidence of inbreeding within populations (Fis = 0.39, 95% CI 0.26–0.55) and significant population differentiation (Fst = 0.16, 0.05–0.24). Analysis of genetic data provided no evidence of isolation by distance, and together with the occurrence of population subdivision, this suggests that there is relatively limited contemporary gene flow among populations. Northern populations of T. erectum tended to have less genetic variability than southern populations, probably as a result of historical factors associated with post glacial migration. Limited opportunities for gene dispersal as a result of low plant densities, the capacity for self-fertilization, and local seed dispersal by ants are likely to be the main factors maintaining contemporary patterns of genetic variation in T. erectum. Key words: allozymes, genetic diversity, gene flow, population genetic structure, Trillium.

Population genetic structure and gene flow in the Japanese sea cucumber Apostichopus japonicus across Toyama Bay, Japan

2012 ◽  
Vol 78 (4) ◽  
pp. 775-783 ◽  
Author(s):  
Taha Soliman ◽  
Manami Kanno ◽  
Akihiro Kijima ◽  
Yuji Yamazaki
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Sea Cucumber ◽  
Apostichopus Japonicus ◽  
Toyama Bay ◽  
Japanese Sea Cucumber

scholarly journals The influence of roads on the fine-scale population genetic structure of the dengue vector Aedes aegypti (Linnaeus)

2021 ◽  
Vol 15 (2) ◽  
pp. e0009139
Author(s):  
Maria Angenica F. Regilme ◽  
Thaddeus M. Carvajal ◽  
Ann–Christin Honnen ◽  
Divina M. Amalin ◽  
Kozo Watanabe
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Aedes Aegypti ◽  
Spatial Scale ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Mosquito Control ◽  
Genetic Admixture ◽  
Fine Spatial Scale ◽  
The Road

Dengue is endemic in tropical and subtropical countries and is transmitted mainly by Aedes aegypti. Mosquito movement can be affected by human-made structures such as roads that can act as a barrier. Roads can influence the population genetic structure of Ae. aegypti. We investigated the genetic structure and gene flow of Ae. aegypti as influenced by a primary road, España Boulevard (EB) with 2000-meter-long stretch and 24-meters-wide in a very fine spatial scale. We hypothesized that Ae. aegypti populations separated by EB will be different due to the limited gene flow as caused by the barrier effect of the road. A total of 359 adults and 17 larvae Ae. aegypti were collected from June to September 2017 in 13 sites across EB. North (N1-N8) and South (S1-S5) comprised of 211 and 165 individuals, respectively. All mosquitoes were genotyped at 11 microsatellite loci. AMOVA FST indicated significant genetic differentiation across the road. The constructed UPGMA dendrogram found 3 genetic groups revealing the clear separation between North and South sites across the road. On the other hand, Bayesian cluster analysis showed four genetic clusters (K = 4) wherein each individual samples have no distinct genetic cluster thus genetic admixture. Our results suggest that human-made landscape features such as primary roads are potential barriers to mosquito movement thereby limiting its gene flow across the road. This information is valuable in designing an effective mosquito control program in a very fine spatial scale.

scholarly journals Microgeographic Population Genetic Structure of Baylisascaris procyonis (Nematoda: Ascaroidae) in Western Michigan Indicates the Grand River Is a Barrier to Gene Flow

2015 ◽  
Vol 101 (6) ◽  
pp. 671 ◽  
Author(s):  
Christina A. Sarkissian ◽  
Sara K. Campbell ◽  
Guha Dharmarajan ◽  
Joseph Jacquot ◽  
L. Kristen Page ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Baylisascaris Procyonis ◽  
Grand River

Population genetic structure in duckweed (Lemna minor, Lemnaceae)

1996 ◽  
Vol 74 (2) ◽  
pp. 222-230 ◽  
Author(s):  
Christopher T. Cole ◽  
Martin I. Voskuil
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Population Genetic ◽  
Lemna Minor ◽  
Vegetative Reproduction ◽  
Low Frequency ◽  
Morphological Differentiation ◽  
Genotypic Diversity ◽  
Allozyme Variation ◽  
Low Levels

Allozyme variation in 11 Minnesota populations of Lemna minor L. was studied, using 11 enzyme systems, resolving 16 putative loci from 285 plants. Significant deviations from Hardy–Weinberg frequencies occurred in several populations that had excesses of heterozygotes at several loci. While genotypic diversity and evenness measures are similar to other vegetatively reproducing plants (D = 0.541, E = 0.607), very few multilocus genotypes per population were found (mean = 4.0). Substantial population structure was evident (FST = 0.407), apparently reflecting low levels of gene flow (Nm = 0.30) despite the capacity of this species for dispersal of plantlets. This low level of gene flow and apparent low frequency of sexual reproduction has produced substantial levels of genetic divergence among populations, despite an absence of morphological differentiation. Keywords: allozymes, genetic structure, hydrophily, Lemna, vegetative dispersal, vegetative reproduction.

scholarly journals Population Genetic Structure of Rhizoctonia oryzae-sativae from Rice in Latin America and Its Adaptive Potential to Emerge as a Pathogen on Urochloa Pastures

2017 ◽  
Vol 107 (1) ◽  
pp. 121-131 ◽  
Author(s):  
Danilo A. dos Santos Pereira ◽  
Paulo C. Ceresini ◽  
Vanina L. Castroagudín ◽  
Lina M. Ramos-Molina ◽  
Edisson Chavarro-Mesa ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Reproductive System ◽  
Population Genetic ◽  
Upland Rice ◽  
Adaptive Potential ◽  
Rhizoctonia Oryzae ◽  
Hardy Weinberg Equilibrium ◽  
Two Populations ◽  
Brazilian Populations

The fungus Rhizoctonia oryzae-sativae is an important pathogen that causes the aggregated sheath spot disease on rice. In this study, we investigated the genetic structure of rice-adapted populations of R. oryzae-sativae sampled from traditional rice-cropping areas from the Paraíba Valley, São Paulo, Brazil, and from Meta, in the Colombian Llanos, in South America. We used five microsatellite loci to measure population differentiation and infer the pathogen’s reproductive system. Gene flow was detected among the three populations of R. oryzae-sativae from lowland rice in Brazil and Colombia. In contrast, a lack of gene flow was observed between the lowland and the upland rice populations of the pathogen. Evidence of sexual reproduction including low clonality, Hardy-Weinberg equilibrium within loci and gametic equilibrium between loci, indicated the predominance of a mixed reproductive system in all populations. In addition, we assessed the adaptive potential of the Brazilian populations of R. oryzae-sativae to emerge as a pathogen to Urochloa spp. (signalgrass) based on greenhouse aggressiveness assays. The Brazilian populations of R. oryzae-sativae were probably only incipiently adapted as a pathogen to Urochloa spp. Comparison between RST and QST showed the predominance of diversifying selection in the divergence between the two populations of R. oryzae-sativae from Brazil.

Sign in / Sign up

Export Citation Format

Share Document