scholarly journals Habitat discontinuities form strong barriers to gene flow among mangrove populations, despite the capacity for long-distance dispersal

2018 ◽  
Vol 25 (2) ◽  
pp. 298-309 ◽  
Author(s):  
Rachel M. Binks ◽  
Margaret Byrne ◽  
Kathryn McMahon ◽  
Georgina Pitt ◽  
Kathy Murray ◽  
...  
2019 ◽  
Vol 104 (3) ◽  
pp. 495-511 ◽  
Author(s):  
Krissa A. Skogen ◽  
Rick P. Overson ◽  
Evan T. Hilpman ◽  
Jeremie B. Fant

Land-use change is among the top drivers of global biodiversity loss, which impacts the arrangement and distribution of suitable habitat for species. Population-level effects include increased isolation, decreased population size, and changes to mutualistic and antagonistic interactions. However, the extent to which species are impacted is determined by life history characteristics including dispersal. In plants, mating dynamics can be changed in ways that can negatively impact population persistence if dispersal of pollen and/or seed is disrupted. Long-distance dispersal has the potential to buffer species from the negative impacts of land-use change. Biotic vectors of long-distance dispersal have been less frequently studied, though specific taxa are known to travel great distances. Here, we describe population genetic diversity and structure in a sphingophilous species that is experiencing habitat fragmentation through land-use change, Oenothera harringtonii W. L. Wagner, Stockh. & W. M. Klein (Onagraceae). We use 12 nuclear and four plastid microsatellite markers and show that pollen dispersal by hawkmoths drives high gene flow and low population differentiation despite a range-wide gradient of land-use change and habitat fragmentation. By separating the contributions of pollen and seed dispersal to gene flow, we show that most of the genetic parameters are driven by hawkmoth-facilitated long-distance pollen dispersal, but populations with small, effective population sizes experience higher levels of relatedness and inbreeding. We discuss considerations for conservation efforts for this and other species that are pollinated by long-distance dispersers.


2011 ◽  
Vol 101 (1) ◽  
pp. 68-76 ◽  
Author(s):  
A. L. Dale ◽  
K. J. Lewis ◽  
B. W. Murray

Dothistroma septosporum has caused a serious needle blight epidemic in the lodgepole pine forests in northwest British Columbia over the past several years. Although ascocarps had been observed in British Columbia, nothing was known about the contribution of sexual reproduction, gene flow and long-distance dispersal to the epidemic. Amplified fragment length polymorphism and mating-type markers in 19 sites were used to generate population and reproductive data. Overall, evidence suggests a mixed mode of reproduction. Haplotypic diversity was high, with 79 unique and 56 shared haplotypes (possible clones) identified from 192 fungal isolates. Overall, mating-type segregation did not differ significantly from 1:1; however, random mating was rejected in most populations in the index of association and parsimony tree-length permutation analyses using the full data set and, when using clone-corrected data sets, more of the smaller populations showed random mating. Two of the smaller populations consistently showed random mating for both tests using both clone-corrected and noncorrected data. High gene flow is suggested by no differentiation between 14 of the 19 sites, several of which came from young plantations where the pathogen was not likely present prior to the current outbreak. The remaining five sites showed some level of divergence, possibly due to historic separation and endemic pathogen populations. Results indicate a high evolutionary potential and long-distance dispersal in this pathogen, important to consider in future forest management.


2013 ◽  
Vol 13 (1) ◽  
pp. 67-74 ◽  
Author(s):  
Claudia Teresa Hornung-Leoni ◽  
Victoria Sosa ◽  
June Simpson ◽  
Katia Gil

Puya raimondii, the giant Peruvian and Bolivian terrestrial bromeliad, is an emblematic endemic Andean species well represented in Huascarán National Park in Peru. This park is the largest reserve of puna (high altitude plateau) vegetation. The objective of this study is to report on genetic variation in populations of P. raimondii from Huascarán and neighboring areas. AFLP profiles with four selective primer combinations were retrieved for 60 individuals from different zones. Genetic variability was estimated and a total of 172 bands were detected, of which 79.1% were polymorphic loci. The results showed genetic differentiation among populations, and gene flow. A cluster analysis showed that individuals of P. raimondii populations located in different mountain systems could be grouped together, suggesting long distance dispersal. Thus, conservation strategies for P. raimondii have to take into account exchange between populations located far apart in distance in order to preserve the genetic diversity of this showy species.


2008 ◽  
Vol 59 (9) ◽  
pp. 761 ◽  
Author(s):  
Alison J. McLean ◽  
Daniel J. Schmidt ◽  
Jane M. Hughes

Long-distance dispersal might be an important mechanism for the maintenance of aquatic insect populations in heterogeneous landscapes. However, these events can be difficult to measure by direct observation because the techniques can be time-consuming, expensive and technically difficult. When dispersal results in gene flow within and between populations, patterns of variation can be detected by genetic methods. The levels of population genetic structuring and the relationship between gene flow and geographical distance were assessed in the mayfly species Bungona narilla (Harker, 1957) in rainforest streams in south-east Queensland that are separated by lowland habitats. An analysis of molecular variance based on mitochondrial DNA data, using a fragment of the cytochrome oxidase I gene, revealed significant differentiation between regions, suggesting that maternal gene flow was restricted. A nested clade analysis revealed patterns of historical (contiguous) range expansions and recent restricted gene flow along with some long-distance dispersal events. Our analyses have shown that populations of B. narilla are significantly structured throughout the species range in south-east Queensland and that the low elevation habitats separating the northern and southern populations are restricting gene flow to some extent.


1979 ◽  
Vol 57 (20) ◽  
pp. 2179-2225 ◽  
Author(s):  
Rudolf M. Schuster

The dispersal of a considerable number, if not the vast majority, of southern hemisphere Hepaticae chiefly belonging to "old" families and suborders can be visualized as resulting primarily from short-range or "step-wise" dispersal, as part of structural communities, before the final disassembly of the presently fragmented Gondwanaland. Often with the disruption of gene flow, disjunct populations of once continuously distributed Gondwanalandic taxa have undergone speciation, in most cases as physical disruption occurred. Significant relict and disjunct distribution patterns for 21 hepatic taxa are mapped and discussed. A discussion of (i) rate of speciation and genus formation, (ii) efficiency of long-distance dispersal, and (iii) the geological background is presented with the purpose of explaining the origins of antipodal distribution patterns within the Hepaticae.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Xaymara M. Serrano ◽  
Iliana B. Baums ◽  
Tyler B. Smith ◽  
Ross J. Jones ◽  
Tonya L. Shearer ◽  
...  

2019 ◽  
Vol 66 (3) ◽  
pp. 227-237
Author(s):  
Paula C Rodríguez-Flores ◽  
Ernesto Recuero ◽  
Yolanda Jiménez-Ruiz ◽  
Mario García-París

Abstract Anostraca are known by their ability for long-distance dispersal, but the existence in several species of deep, geographically structured mtDNA lineages suggests their populations are subjected to allopatric differentiation, isolation, and prevalence of local scale dispersion. Tanymastix stagnalis is one of the most widespread species of Anostraca and previous studies revealed an unclear geographical pattern of mtDNA genetic diversity. Here, we analyze populations from the Iberian and Italian Peninsulas, Central Europe, and Scandinavia, with the aim to characterize the patterns of genetic diversity in a spatio-temporal framework using mtDNA and nuclear markers to test gene flow among close populations. For these aims we built a time-calibrated phylogeny and carried out Bayesian phylogeographic analyses using a continuous diffusion model. Our results indicated that T. stagnalis presents a deeply structured genetic diversity, including 7 ancient lineages, some of them even predating the Pleistocene. The Iberian Peninsula harbors high diversity of lineages, with strong isolation and recent absence of gene flow between populations. Dispersal at local scale seems to be the prevailing dispersal mode of T. stagnalis, which exhibits a pattern of isolation-by-distance in the Iberian Peninsula. We remark the vulnerability of most of these lineages, given the limited known geographic distribution of some of them, and the high risk of losing important evolutionary potential for the species.


PLoS ONE ◽  
2013 ◽  
Vol 8 (10) ◽  
pp. e77125 ◽  
Author(s):  
Micaela E. Martinez-Bakker ◽  
Stephanie K. Sell ◽  
Bradley J. Swanson ◽  
Brendan P. Kelly ◽  
David A. Tallmon

2019 ◽  
Vol 128 (3) ◽  
pp. 592-602 ◽  
Author(s):  
Jianqiang Li ◽  
Lei Lv ◽  
Pengcheng Wang ◽  
Yong Wang ◽  
Ben J Hatchwell ◽  
...  

Abstract Animal dispersal patterns have important implications for many biological processes, but the measurement of dispersal is challenging and often requires the use of complementary approaches. In this study, we investigated the local-scale sex-biased dispersal pattern in a social bird, the black-throated tit (Aegithalos concinnus), in central China. Spatial genetic autocorrelation analyses suggested that significant fine-scale genetic structure existed in males but not in females. Mark–recapture analyses of ringed individuals also showed that female offspring were more dispersive than male offspring, supporting genetic evidence of local female-biased dispersal. These results were contrary to a previous finding of male-biased long-distance dispersal in this species that was based on analyses of gene flow across the species range in China. This implies that the species might potentially have a scale-dependent dispersal strategy, with females frequently dispersing further than males at the local level, but with a proportion of males occasionally dispersing over long distances and contributing more to gene flow at a larger geographical scale. Long-distance dispersal by male black-throated tits might be induced by competition for resources or by unfavourable environmental conditions, warranting further investigation, but our findings increase the evidence that geographical scale is an important factor to be considered when investigating animal dispersal patterns.


2020 ◽  
Vol 101 (3) ◽  
pp. 790-803
Author(s):  
Niko Balkenhol ◽  
Michael K Schwartz ◽  
Robert M Inman ◽  
Jeffrey P Copeland ◽  
John S Squires ◽  
...  

Abstract Climate change can have particularly severe consequences for high-elevation species that are well-adapted to long-lasting snow conditions within their habitats. One such species is the wolverine, Gulo gulo, with several studies showing a strong, year-round association of the species with the area defined by persistent spring snow cover. This bioclimatic niche also predicts successful dispersal paths for wolverines in the contiguous United States, where the species shows low levels of genetic exchange and low effective population size. Here, we assess the influence of additional climatic, vegetative, topographic, and anthropogenic, variables on wolverine genetic structure in this region using a multivariate, multiscale, landscape genetic approach. This approach allows us to detect landscape-genetic relationships both due to typical, small-scale genetic exchange within habitat, as well as exceptional, long-distance dispersal among habitats. Results suggest that a combination of snow depth, terrain ruggedness, and housing density, best predict gene flow in wolverines, and that the relative importance of variables is scale-dependent. Environmental variables (i.e., isolation-by-resistance, IBR) were responsible for 79% of the explained variation at small scales (i.e., up to ~230 km), and 65% at broad scales (i.e., beyond ~420 km). In contrast, a null model based on only space (i.e., isolation-by-distance, IBD) accounted only for 17% and 11% of the variation at small and broad scales, respectively. Snow depth was the most important variable for predicting genetic structures overall, and at small scales, where it contributed 43% to the variance explained. At broad spatial scales, housing density and terrain ruggedness were most important with contributions to explained variation of 55% and 25%, respectively. While the small-scale analysis most likely captures gene flow within typical wolverine habitat complexes, the broad-scale analysis reflects long-distance dispersal across areas not typically inhabited by wolverines. These findings help to refine our understanding of the processes shaping wolverine genetic structure, which is important for maintaining and improving functional connectivity among remaining wolverine populations.


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