Tag Archives: natural selection

The Neanderthal admixture plot thickens…

Previous studies of archaic admixture from Altai Neanderthals and Denisovans into modern humans outside of Africa have put forth several lines of evidence for gene flow from Neanderthals into common ancestors of Eurasian populations, from Denisovans into ancestors of modern … Continue reading

Posted in bioinformatics, evolution, genomics, mutation, natural history, next generation sequencing, Paleogenomics, population genetics, speciation | Tagged , , , | 2 Comments

Genomics of Hybridization – Part II, Top three of 2015

Death Valley pupfishes (Cyprinodon) are among the most endangered vertebrates on earth, with small inbred populations, with heavy risks of extinction in extreme environments. Martin et al. (2016) in a recent publication quantify diversity and adaptability in a very small population … Continue reading

Posted in bioinformatics, conservation, genomics, methods, natural history, next generation sequencing, population genetics, R, software, speciation, STRUCTURE, theory | Tagged , , , , | Leave a comment

Genomics of Hybridization – Part 1

In a series of articles, I will discuss recent advances in hybridization genomics – the fundamentals of adaptive introgression, “islands of speciation”, differential gene flow, and linked selection have been discussed in my previous posts (here, here, and also at … Continue reading

Posted in adaptation, evolution, genomics, methods, natural history, next generation sequencing, pedigree, phylogenetics, plants, population genetics, RNAseq, software, speciation, species delimitation, STRUCTURE, theory, transcriptomics | Tagged , , , , , , | Leave a comment

Earthquakes and rapid evolution

The 1964 Alaskan earthquake was landscape-altering in creating/uplifting numerous islands in the Gulf of Alaska, providing an ideal system to study adaptive evolution of diversification in affected species – the threespine stickleback (Gasterosteus aculeatus) being a widely studied example. In … Continue reading

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Anti-predatory adaptations in sticklebacks and butterflies

Two recent studies analyze character shifts in response to different selection regimes – (1) Mullerian mimicry wing patterns in Heliconius butterflies, and (2) anti-intraguild-predator adaptations in armor and shape of threespine sticklebacks. Hoyal Cuthill and Charleston 2015 Wing patterning genes … Continue reading

Posted in adaptation, Coevolution, evolution, genomics, natural history, phylogenetics, phylogeography, population genetics, selection, speciation | Tagged , , , | Leave a comment

Genomics of domestication in chicken and cattle

Two recent studies attempt to understand the process of adaptive evolution in domestication and artificial selection by characterizing (a) sweeps, and their association with phenotypes in extant hybrid lines (Sheng et al. 2015), and (b) phylogenomic position of an extinct … Continue reading

Posted in adaptation, bioinformatics, domestication, evolution, genomics, natural history, Paleogenomics, phylogeography, population genetics, selection, speciation, STRUCTURE | Tagged , , , , , , | 1 Comment

On background selection in Ficedula flycatchers

Several recent studies (including those I wrote about last week) use genome-wide scans of differentiation to understand evolutionary mechanisms behind high or low divergence. However, there has been contentious support for and against these differentiation islands being due to differential … Continue reading

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Introgression history in sticklebacks and oaks

Speciation theory has many monikers for differential gene flow – migration, introgression, admixture, hybridization, secondary contact. As a homogenizing process, gene flow at large acts to reduce differentiation between populations post-divergence. However, selection and demography affect the rates of gene … Continue reading

Posted in adaptation, evolution, genomics, natural history, phylogenetics, population genetics, selection, speciation, species delimitation | Tagged , , , , , | 1 Comment

Sweptaway – Part 2

Numerous methods have been developed over the last few years for the detection of selective sweeps (hard and soft – see my previous post). This week, we look at three new studies that (a) compare existing methods to detect sweeps … Continue reading

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Small mammalian genomics of adaptation

While large mammals have had their day on our blog, two recent studies on small mammals reveal the genetics of size evolution in island mice, and differential introgression of mitochondrial and nuclear genomes in chipmunks – steps towards understanding the … Continue reading

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