The Experts below are selected from a list of 22443 Experts worldwide ranked by ideXlab platform
Ole Seehausen - One of the best experts on this subject based on the ideXlab platform.
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speciation through sensory drive in cichlid fish
Nature, 2008Co-Authors: Ole Seehausen, Yohey Terai, Isabel S Magalhaes, Karen L Carleton, Hillary D J Mrosso, Ryutaro Miyagi, Inke Van Der SluijsAbstract:Theoretically, divergent selection on sensory systems can cause speciation through sensory drive. However, empirical evidence is rare and incomplete. Here we demonstrate sensory drive speciation within island populations of cichlid fish. We identify the ecological and molecular basis of divergent evolution in the cichlid visual system, demonstrate associated divergence in male colouration and female preferences, and show subsequent differentiation at neutral loci, indicating reproductive Isolation. Evidence is replicated in several pairs of sympatric populations and species. Variation in the slope of the environmental gradients explains variation in the progress towards speciation: speciation occurs on all but the steepest gradients. This is the most complete demonstration so far of speciation through sensory drive without Geographical Isolation. Our results also provide a mechanistic explanation for the collapse of cichlid fish species diversity during the anthropogenic eutrophication of Lake Victoria.
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sensory drive in cichlid speciation
The American Naturalist, 2006Co-Authors: Martine E Maan, Kees D Hofker, Jacques J M Van Alphen, Ole SeehausenAbstract:The role of selection in speciation is a central yet poorly understood problem in evolutionary biology. The rapid radiations of extremely colorful cichlid fish in African lakes have fueled the hypothesis that sexual selection can drive species divergence without Geographical Isolation. Here we present experimental evidence for a mechanism by which sexual selection becomes divergent: in two sibling species from Lake Victoria, female mating preferences for red and blue male nuptial coloration coincide with their context-independent sensitivities to red and blue light, which in turn correspond to a difference in ambient light in the natural habitat of the species. These results suggest that natural selection on visual performance, favoring different visual properties in different spectral environments, may lead to divergent sexual selection on male nuptial coloration. This interplay of ecological and sexual selection along a light gradient may provide a mechanism of rapid speciation through divergent sensory drive.
Inke Van Der Sluijs - One of the best experts on this subject based on the ideXlab platform.
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speciation through sensory drive in cichlid fish
Nature, 2008Co-Authors: Ole Seehausen, Yohey Terai, Isabel S Magalhaes, Karen L Carleton, Hillary D J Mrosso, Ryutaro Miyagi, Inke Van Der SluijsAbstract:Theoretically, divergent selection on sensory systems can cause speciation through sensory drive. However, empirical evidence is rare and incomplete. Here we demonstrate sensory drive speciation within island populations of cichlid fish. We identify the ecological and molecular basis of divergent evolution in the cichlid visual system, demonstrate associated divergence in male colouration and female preferences, and show subsequent differentiation at neutral loci, indicating reproductive Isolation. Evidence is replicated in several pairs of sympatric populations and species. Variation in the slope of the environmental gradients explains variation in the progress towards speciation: speciation occurs on all but the steepest gradients. This is the most complete demonstration so far of speciation through sensory drive without Geographical Isolation. Our results also provide a mechanistic explanation for the collapse of cichlid fish species diversity during the anthropogenic eutrophication of Lake Victoria.
Xiaoquan Wang - One of the best experts on this subject based on the ideXlab platform.
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plant recolonization in the himalaya from the southeastern qinghai tibetan plateau Geographical Isolation contributed to high population differentiation
Molecular Phylogenetics and Evolution, 2010Co-Authors: Yuzhi Cun, Xiaoquan WangAbstract:The Himalaya–Hengduan Mountains region (HHM) in the southern and southeastern Qinghai-Tibetan Plateau (QTP) is considered an important reservoir and a differentiation center for temperate and alpine plants in the Cenozoic. To reveal how plants responded to the Quaternary climatic oscillations in the QTP, the phyloGeographical histories of a few subalpine and alpine plants have been investigated, but nearly all studies used only uniparentally inherited cytoplasmic DNA markers, and only a couple of them included sampling from the Himalaya. In this study, range-wide genetic variation of the Himalayan hemlock (Tsuga dumosa), an important forest species in the HHM, was surveyed using DNA markers from three genomes. All markers revealed genetic depauperation in the Himalaya and richness in the Hengduan Mountains populations. Surprisingly, population differentiation of this wind-pollinated conifer is very high in all three genomes, with few common and many private nuclear gene alleles. These results, together with fossil evidence, clearly indicate that T. dumosa recolonized the Himalaya from the Hengduan Mountains before the Last Glacial Maximum (LGM), accompanied with strong founder effects, and the influence of the earlier glaciations on demographic histories of the QTP plants could be much stronger than that of the LGM. The strong population differentiation in T. dumosa could be attributed to restricted gene flow caused by the complicated topography in the HHM that formed during the uplift of the QTP, and thus sheds lights on the importance of Geographical Isolation in the development of high plant species diversity in this biodiversity hotspot.
Franco Cruzjofre - One of the best experts on this subject based on the ideXlab platform.
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Geographical Isolation and genetic differentiation the case of orestias ascotanensis teleostei cyprinodontidae an andean killifish inhabiting a highland salt pan
Biological Journal of The Linnean Society, 2016Co-Authors: Franco Cruzjofre, Pamela Morales, Irma Vila, Yareli Esquergarrigos, Bernard Hugueny, Philippe Gaubert, Elie Poulin, Marco A MendezAbstract:Orestias ascotanensis is a killifish endemic to the Ascotan salt pan in the Chilean Altiplano, where it inhabits 12 springs with different degrees of Isolation. This species is a suitable model for studying the effect of serial Geographical Isolations on the differentiation process among populations. The present study examines the genetic variation and structure of the species using mitochondrial DNA control region sequences and eight microsatellite loci, analyzing populations across its distribution range. The evaluation of genetic variation revealed high levels of diversity within the species. The genetic structure analysis showed the existence of four differentiated groups: two groups were formed by the springs located in the northern and southern extremes of the salt pan and two groups were found in the centre of the salt pan. The latter two groups were formed by several springs, most likely as a consequence of the South American summer monsoon that could connect them and allow gene flow. The patterns of genetic differentiation appear to be determined based on the physical Isolation of the populations. This Isolation may be the result of a combination of factors, including Geographical distance, a historical decrease in water levels and altitude differences in the springs of the salt pan. Therefore, this system is a rare example in which hydrological factors can explain genetic differentiation on a very small scale.
Jonathan B Losos - One of the best experts on this subject based on the ideXlab platform.
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quantifying the roles of ecology and geography in spatial genetic divergence
Ecology Letters, 2013Co-Authors: Ian J. Wang, Richard E Glor, Jonathan B LososAbstract:Investigating the properties of ecological landscapes that influence gene flow among populations can provide key insights into the earliest stages of biological divergence. Both ecological and Geographical factors can reduce gene flow, which can lead to population divergence, but we know little of the relative strengths of these phenomena in nature. Here, we use a novel application of structural equation modelling to quantify the contributions of ecological and Geographical Isolation to spatial genetic divergence in 17 species of Anolis lizards. Our comparative analysis shows that although both processes contributed significantly, Geographical Isolation explained substantially more genetic divergence than ecological Isolation (36.3 vs. 17.9% of variance respectively), suggesting that despite the proposed ubiquity of ecological divergence, non-ecological factors play the dominant role in the evolution of spatial genetic divergence.
