Search results for "GENE FLOW"
showing 10 items of 177 documents
Genome architecture enables local adaptation of Atlantic cod despite high connectivity
2017
Adaptation to local conditions is a fundamental process in evolution; however, mechanisms maintaining local adaptation despite high gene flow are still poorly understood. Marine ecosystems provide a wide array of diverse habitats that frequently promote ecological adaptation even in species characterized by strong levels of gene flow. As one example, populations of the marine fish Atlantic cod (Gadus morhua) are highly connected due to immense dispersal capabilities but nevertheless show local adaptation in several key traits. By combining population genomic analyses based on 12K single-nucleotide polymorphisms with larval dispersal patterns inferred using a biophysical ocean model, we show…
The genomic history of the Iberian Peninsula over the past 8000 years
2019
We assembled genome-wide data from 271 ancient Iberians, of whom 176 are from the largely unsampled period after 2000 BCE, thereby providing a high-resolution time transect of the Iberian Peninsula. We document high genetic substructure between northwestern and southeastern hunter-gatherers before the spread of farming. We reveal sporadic contacts between Iberia and North Africa by ~2500 BCE and, by ~2000 BCE, the replacement of 40% of Iberia's ancestry and nearly 100% of its Y-chromosomes by people with Steppe ancestry. We show that, in the Iron Age, Steppe ancestry had spread not only into Indo-European-speaking regions but also into non-Indo-European-speaking ones, and we reveal that pre…
Northern European Salmo trutta (L.) populations are genetically divergent across geographical regions and environmental gradients
2020
The salmonid fish Brown trout is iconic as a model for the application of conservation genetics to understand and manage local interspecific variation. However, there is still scant information about relationships between local and large-scale population structure, and to what extent geographical and environmental variables are associated with barriers to gene flow. We used information from 3,782 mapped SNPs developed for the present study and conducted outlier tests and gene–environment association (GEA) analyses in order to examine drivers of population structure. Analyses comprised >2,600 fish from 72 riverine populations spanning a central part of the species' distribution in norther…
Very high MHC Class IIB diversity without spatial differentiation in the mediterranean population of greater Flamingos.
2017
WOS: 000397335400001
Demographic history has shaped the strongly differentiated corkwing wrasse populations in Northern Europe
2019
Understanding the biological processes involved in genetic differentiation and divergence between populations within species is a pivotal aim in evolutionary biology. One particular phenomenon that requires clarification is the maintenance of genetic barriers despite the high potential for gene flow in the marine environment. Such patterns have been attributed to limited dispersal or local adaptation, and to a lesser extent to the demographic history of the species. The corkwing wrasse (Symphodus melops) is an example of a marine fish species where regions of particular strong divergence are observed. One such genetic break occurred at a surprisingly small spatial scale (FST ~0.1), over a s…
Habitat Discontinuities Separate Genetically Divergent Populations of a Rocky Shore Marine Fish.
2016
Habitat fragmentation has been suggested to be responsible for major genetic differentiations in a range of marine organisms. In this study, we combined genetic data and environmental information to unravel the relative role of geography and habitat heterogeneity on patterns of genetic population structure of corkwing wrasse (Symphodus melops), a rocky shore species at the northern limit of its distribution range in Scandinavia. Our results revealed a major genetic break separating populations inhabiting the western and southern coasts of Norway. This genetic break coincides with the longest stretch of sand in the whole study area, suggesting habitat fragmentation as a major driver of genet…
Ecological and historical determinants of population genetic structure and diversity in the Mediterranean shrubRosmarinus officinalis(Lamiaceae)
2015
Population genetic studies of widespread Mediterranean shrubs are scarce compared with those of trees and narrow endemics or studies from phylogeographical perspectives, despite the key role these species may play in Mediterranean ecosystems. Knowledge on the effect of ecological factors in shaping their genetic patterns is also limited. In this study we investigate genetic diversity and population structure across 18 populations of Rosmarinus officinalis, a Mediterranean shrubland plant. Populations were sampled along two elevational gradients, one each on calcareous and siliceous soils in a mountain system in the eastern Iberian Peninsula, to decipher the effect of ecological factors on t…
The role of the Strait of Gibraltar in shaping the genetic structure of the Mediterranean Grenadier, Coryphaenoides mediterraneus, between the Atlant…
2017
24 pages, 4 figures, 4 tables, supplementary information https://dx.doi.org/10.1371/journal.pone.0174988.-- Data Availability: The mtDNA COI sequences can be accessed at BOLD systems through the sample ID: ME-9911; ME-11972; ME-13727; GLF011. New mtDNA COI sequences can be accessed at GenBank by the accession numbers KY345206 - KY345398. GenBank accession numbers for close related species of C. mediterraneus are: Coryphaenoides striaturus - KX656427.1, KX656428.1; Coryphaenoides murray - KX656411.1, KX656410.1; Coryphaenoides carapinus - KX656382.1, KX656381.1; Coryphaenoides brevibarbis - KX656377.1, KX656376.1, KX656375.1. An alignment in fasta with all the haplotypes and respective frequ…
Gene flow in the European coal tit, Periparus ater (Aves: Passeriformes): Low among Mediterranean populations but high in a continental contact zone
2018
Abstract Extant phylogeographical patterns of Palearctic terrestrial vertebrates are generally believed to have originated from glacial range fragmentation. Post-Pleistocene range expansions have led to the formation of secondary contact zones among genetically distinct taxa. For coal tits (Periparus ater), such a contact zone has been localized in Germany. In this study, we quantified gene flow between Fennoscandian and southern European coal tits using a set of 13 microsatellite loci. STRUCTURE analysis revealed four genetic clusters, two occurring on Mediterranean islands. German populations were genetically admixed but introgression of southern alleles was evident for Fennoscandian popu…
Genetic variation of naturally growing olive trees in Israel: from abandoned groves to feral and wild?
2016
Background Naturally growing populations of olive trees are found in the Mediterranean garrigue and maquis in Israel. Here, we used the Simple Sequence Repeat (SSR) genetic marker technique to investigate whether these represent wild var. sylvestris. Leaf samples were collected from a total of 205 trees at six sites of naturally growing olive populations in Israel. The genetic analysis included a multi-locus lineage (MLL) analysis, Rousset’s genetic distances, Fst values, private alleles, other diversity values and a Structure analysis. The analyses also included scions and suckers of old cultivated olive trees, for which the dominance of one clone in scions (MLL1) and a second in suckers (…