Tag Archives: natural selection

Sweptaway – Part 1

Posted on 3 Sep, 2015 by Arun Sethuraman

Brace yourselves for a series of new posts on selection, especially with articles from the special Molecular Ecology issue on “Detecting selection in natural populations: making sense of genome scans and towards alternative solutions” starting to roll out! Selective sweeps … Continue reading →

Posted in adaptation, evolution, genomics, mutation, population genetics, selection, speciation, theory | Tagged , , , , , | Leave a comment

And who made your beer?

Posted on 27 Aug, 2015 by Arun Sethuraman

In the spirit of it being almost Friday, and while we’re on the topic of your favorite beverages – perhaps wine puts you to sleep, couldn’t care less where it came from, but prefer the bitterness of lager beers at your … Continue reading →

Posted in adaptation, evolution, genomics, natural history, next generation sequencing, phylogenetics, population genetics, selection, speciation, yeast | Tagged , , , , | 2 Comments

Selection scans, and the genomics of adaptive/maladaptive introgression

Posted on 6 Aug, 2015 by Arun Sethuraman

Natural selection, and the adaptive evolution of hybrid reproductive incompatibilities post divergence are known to be major drivers of speciation. At the phenotype level, these manifest as fitness differences between introgressing populations. At the genomic level, speciation “genes” or “islands” … Continue reading →

Posted in adaptation, Coevolution, evolution, genomics, Molecular Ecology, the journal, mutation, natural history, population genetics, selection, speciation, theory | Tagged , , , , | 3 Comments

The Butterfly Effect

Posted on 9 Jul, 2015 by Arun Sethuraman

This might just take the prize for the ‘spiciest’ story in molecular co-evolution for 2015, yet. While a lot of the press coverage sounds like caterpillar thanksgiving, the science behind this study stands for the almost incredible power of molecular phylogenetics … Continue reading →

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

Societal constructs, and Genetic diversity

Posted on 2 Jul, 2015 by Arun Sethuraman

While we grapple with numerous discoveries of variation in genomic diversity in humans, interest has subsequently risen in understanding their causes/results. Two recent papers describe experiments to determine (a) the effects of marital rules (who gets to marry whom) on … Continue reading →

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Old dogs, and 'carnivorous' pandas

Posted on 4 Jun, 2015 by Arun Sethuraman

It was a good fortnight for large mammals! Two recent studies attempt to date the emergence of modern canids, and offer insights into the gut microbiomes of giant pandas. Ancient Wolf Genome Reveals an Early Divergence of Domestic Dog Ancestors and … Continue reading →

Posted in adaptation, evolution, genomics, metagenomics, microbiology, natural history, Paleogenomics, population genetics, speciation | Tagged , , , | Leave a comment

Sexual selection and population fitness

Posted on 28 May, 2015 by Arun Sethuraman

Sexual selection or non-random mate choice acts to ‘filter’ out less competitive/desirable phenotypes from a population. In the presence of small effect mutation loads, i.e. small fitness differences between a mutation-free population, and one with persistent deleterious mutations, sexual selection … Continue reading →

Posted in adaptation, evolution, mutation, population genetics | Tagged , , , | 1 Comment

Genomic diversity and secondary contact

Posted on 21 May, 2015 by Arun Sethuraman

Under a divergence, or isolation model, the genomes of individuals in a daughter-population are expected to harbor greater differentiation relative to its sister-population, and lower differentiation within the population (after sufficient time since divergence). Divergence thus is a mechanism of … Continue reading →

Posted in evolution, genomics, next generation sequencing, population genetics, theory | Tagged , , | 1 Comment

Quantifying risks of consanguineous mating in humans

Posted on 30 Apr, 2015 by Arun Sethuraman

The efficacy of selection in purging a deleterious mutation from a randomly mating population depends on numerous factors, including dominance effects of alleles – see my previous posts. Simplistically, most new mutations are expected to be heterozygotic, and be purged … Continue reading →

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dN(eutralist) < dS(electionist) Part 5

Posted on 16 Apr, 2015 by Arun Sethuraman

The neutral theory predicts that species with small census (and effective) population sizes are subject to greater drift (or allele frequency fluctuations), and vice versa. In other words, species with larger population sizes are expected to maintain more neutral diversity … Continue reading →

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