Tag Archives: population structure

Unbalanced population sampling and STRUCTURE

The utility and intuition offered by the program STRUCTURE, and more generally, the ‘admixture’ model of Pritchard et al. (2000) are unquestioned – with tens of thousands of citations, it retains its lead among the most popular population genetics software. … Continue reading

Posted in bioinformatics, genomics, howto, methods, population genetics, software, STRUCTURE | Tagged , , | 1 Comment

On (mis)interpreting STRUCTURE/ADMIXTURE results

STRUCTURE, ADMIXTURE and other similar software are among the most cited programs in modern population genomics. They are algorithms that estimate allele frequencies and admixture proportions under the premise that sampled genotypes are derived from one of “K” ancestral populations, … Continue reading

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The Great Migration and African-American Genomic History

Over 45 million African-Americans share a recent common history largely shaped by “The Great Migration” (1910-1970) from out of the Southern United States. And yet, the admixture history of the African-American community, and its consequences for public health are little … Continue reading

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Ice-Age Euro-trips

Recent works that attempt to get at human migrations inside Europe paint a complex portrait of migratory events, admixture with archaic hominids, and adaptive evolution to new geographies, and a changing global climate. Analyzing whole genomes of 51 ancient humans … Continue reading

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Opening Pandora's box: PSMC and population structure

Essentially, all models are wrong, but some are useful. — George Box Publication of the Li and Durbin’s 2011 paper titled “Inference of human population history from individual whole-genome sequences” was a milestone in the inference of demography. By allowing … Continue reading

Posted in bioinformatics, methods, Paleogenomics, population genetics, theory | Tagged , , , , | 6 Comments

Finding hidden structure in uneven data

If you are a population geneticist, your work might include sampling a bunch of individuals and figuring out who is related to who. Seems simple right? Before you can ask questions about differences or similarities between groups, you have to understand what … Continue reading

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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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Long distance dispersal of modern humans outside of Africa

Long distance dispersal (LDD) has long known to be an artifact of human migrations out of Africa. However, the effects of LDD on modern human diversity, and models of LDD in human colonization are yet to be characterized. Using an … Continue reading

Posted in evolution, genomics, natural history, population genetics | Tagged , , , , , | 2 Comments