scholarly journals Gene flow does not prevent personality and morphological differentiation between two blue tit populations

2018 ◽  
Vol 31 (8) ◽  
pp. 1127-1137 ◽  
Author(s):  
Gabrielle Dubuc-Messier ◽  
Samuel P. Caro ◽  
Charles Perrier ◽  
Kees van Oers ◽  
Denis Réale ◽  
...  
Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 435
Author(s):  
Thijs M. P. Bal ◽  
Alejandro Llanos-Garrido ◽  
Anurag Chaturvedi ◽  
Io Verdonck ◽  
Bart Hellemans ◽  
...  

There is a general and solid theoretical framework to explain how the interplay between natural selection and gene flow affects local adaptation. Yet, to what extent coexisting closely related species evolve collectively or show distinctive evolutionary responses remains a fundamental question. To address this, we studied the population genetic structure and morphological differentiation of sympatric three-spined and nine-spined stickleback. We conducted genotyping-by-sequencing and morphological trait characterisation using 24 individuals of each species from four lowland brackish water (LBW), four lowland freshwater (LFW) and three upland freshwater (UFW) sites in Belgium and the Netherlands. This combination of sites allowed us to contrast populations from isolated but environmentally similar locations (LFW vs. UFW), isolated but environmentally heterogeneous locations (LBW vs. UFW), and well-connected but environmentally heterogenous locations (LBW vs. LFW). Overall, both species showed comparable levels of genetic diversity and neutral genetic differentiation. However, for all three spatial scales, signatures of morphological and genomic adaptive divergence were substantially stronger among populations of the three-spined stickleback than among populations of the nine-spined stickleback. Furthermore, most outlier SNPs in the two species were associated with local freshwater sites. The few outlier SNPs that were associated with the split between brackish water and freshwater populations were located on one linkage group in three-spined stickleback and two linkage groups in nine-spined stickleback. We conclude that while both species show congruent evolutionary and genomic patterns of divergent selection, both species differ in the magnitude of their response to selection regardless of the geographical and environmental context.


1996 ◽  
Vol 74 (2) ◽  
pp. 222-230 ◽  
Author(s):  
Christopher T. Cole ◽  
Martin I. Voskuil

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.


2014 ◽  
Vol 14 (1) ◽  
Author(s):  
Eddy J Dowle ◽  
Mary Morgan-Richards ◽  
Steven A Trewick

1997 ◽  
Vol 75 (6) ◽  
pp. 925-931 ◽  
Author(s):  
J. -F. Renno ◽  
T. Winkel ◽  
F. Bonnefous ◽  
G. Bezançon

Under natural conditions, wild and cultivated pearl millet, Pennisetum glaucum (L.) R.Br., exchanged genes for millenia and, nevertheless, maintain high morphological differentiation. Under experimental conditions in the Sahel, hybridization between wild and cultivated pearl millet was measured using isozymic markers and interpreted in relation to the phenology of the plants. Gene flows were asymmetric, engendering 8% of hybrids in the progeny of the wild phenotype, 45% in that of the cultivated phenotype, and 39% in that of the intermediate "shibra" phenotype; these last two phenotypes constitute the sample of cultivated pearl millet. The proportion of hybrids in the progeny of the wild sample was time dependent during the flowering phase of cultivated pearl millet. The proportion of hybrids produced by the cultivated pearl millet was not time dependent. In the seeds produced by the cultivated phenotype along its reproductive phase, the proportion of viable seeds was negatively correlated with the frequency of hybrids. Likewise, the speed of germination of seeds produced by the cultivated or the shibra phenotypes was negatively correlated with the frequency of the hybrids that they contained. The effects of balancing among genetic intermixing, isolation and reproduction barriers, and differential anthropic and natural selection pressures are discussed to better understand the evolution and the maintenance of the polymorphism of Pennisetum glaucum. Key words: pearl millet, wild pearl millet, Pennisetum glaucum, gene flow, domestication, hybrid.


2005 ◽  
Vol 2 (1) ◽  
pp. 85-87 ◽  
Author(s):  
Juan Carlos Senar ◽  
Antoni Borras ◽  
Josep Cabrera ◽  
Toni Cabrera ◽  
Mats Björklund

It is well known theoretically that gene flow can impede genetic differentiation between populations. In this study, we show that in a highly mobile bird species, where dispersal is well documented, there is a strong genetic and morphological differentiation over a very short geographical scale (less than 5 km). Allocation tests revealed that birds caught in one area were assigned genetically to the same area with a very high probability, in spite of current gene flow. Populations were also morphologically differentiated. The results suggest that the relationship between gene flow and differentiation can be rather complicated and non-intuitive.


The Auk ◽  
2020 ◽  
Vol 137 (4) ◽  
Author(s):  
Luz E Zamudio-Beltrán ◽  
Juan Francisco Ornelas ◽  
Andreia Malpica ◽  
Blanca E Hernández-Baños

Abstract Genetic variation and phylogeographic studies have been crucial for understanding mechanisms of speciation. We analyzed genetic variation and phylogeography to reconstruct the demographic history of the Rivoli’s Hummingbird (Eugenes fulgens) species complex and also evaluated their morphological differentiation. This widely distributed species inhabits the highlands of Mexico and northern Central America, with 2 subspecies separated by the Isthmus of Tehuantepec (west: E. f. fulgens, east: E. f. viridiceps). We surveyed genetic variation in 2 mitochondrial DNA markers (mtDNA, with 129 individuals) and nuclear DNA (6 microsatellites, with 85 individuals). We also inferred the demographic history, estimated divergence times, and analyzed morphological variation using 470 vouchered specimens. We modeled the current potential distribution of the species using ecological niche modeling and projected it into the past to model the effects of the Pleistocene climatic cycles. Haplotype networks, pairwise FST comparisons, AMOVA, and morphological analysis revealed differences between geographically isolated populations separated by the Isthmus of Tehuantepec (IT; corresponding to the 2 recognized subspecies: fulgens and viridiceps), and by the Motagua-Polochic-Jocotán (MPJ) system fault. Demographic scenarios revealed a contraction in distribution during the last interglacial, and expansion during the Last Glacial Maximum (LGM) with little change since the LGM. Divergence between groups separated by the Isthmus of Tehuantepec ~59,600 yr ago occurred in the presence of gene flow, suggesting that the Isthmus of Tehuantepec is a semipermeable barrier to gene flow. STRUCTURE analyses of microsatellite data detected 3 genetically differentiated groups. Several results fit a model of recent lineage divergence, including a significant signal of genetic differentiation, demographic expansion, decreased gene flow from past to present, and northward expansion during the LGM and contraction during the interglacial periods. We conclude that the genetic differentiation of E. fulgens in the Madrean Pine-Oak Woodlands resulted from recent geographical isolation of populations separated by natural barriers (IT and MPJ).


Genetics ◽  
1979 ◽  
Vol 92 (1) ◽  
pp. 247-262
Author(s):  
Nils Ryman ◽  
Fred W Allendorf ◽  
Gunnar Ståhl

ABSTRACT Two reproductively isolated demes of brown trout coexist in a small Swedish mountain lake, Lake Bunnersjoarna. We electrophoretically examined 102 specimens from that lake for 27 enzymes encoded by 54 loci. The two demes are fixed for different alleles at a lactate dehydrogenase locus (LDH-1); statistically significant allele frequency differences at five other loci further support the complete lack of gene flow between these demes. There are significant differences in growth rates between fish in the two demes, but no further morphological differentiation has been detected.——In light of these findings, the genetic distance between these populations is surprisingly small (NEI'S I=0.975). These demes represent one of the least genetically divergent, reproductively isolated sympatric pair of vertebrate populations that have been identified. The results are discussed from both an evolutionary and ecological perspective.


2012 ◽  
Vol 58 (3) ◽  
pp. 440-452 ◽  
Author(s):  
C. Macías Garcia ◽  
G. Smith ◽  
C. González Zuarth ◽  
J. A. Graves ◽  
M. G. Ritchie

Abstract Sexual dimorphism is often used as a proxy for the intensity of sexual selection in comparative studies of sexual selection and diversification. The Mexican Goodeinae are a group of livebearing freshwater fishes with large variation between species in sexual dimorphism in body shape. Previously we found an association between variation in morphological sexual dimorphism between species and the amount of gene flow within populations in the Goodeinae. Here we have examined if morphological differentiation within a single dimorphic species is related to assortative mating or gene flow between populations. In the Amarillo fish Girardinichthys multiradiatus studies have shown that exaggerated male fins are targets of female preferences. We find that populations of the species differ in the level of sexual dimorphism displayed due to faster evolution of differences in male than female morphology. However, this does not predict variation in assortative mating tests in the laboratory; in fact differences in male morphology are negatively correlated with assortative mating. Microsatellite markers reveal significant genetic differences between populations. However, gene flow is not predicted by either morphological differences or assortative mating. Rather, it demonstrates a pattern of isolation by distance with greater differentiation between watersheds. We discuss the caveats of predicting behavioural and genetic divergence from so-called proxies of sexual selection.


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