Category Archives: population genetics

dN(eutralist) < dS(electionist) Part 5

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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The gopher tortoise gut microbiome

A few weeks ago I wrote about a study on socially structured gut microbiomes in wild baboons. Well, now I’m here to tell you about a new study that examined the population structure of tortoise gut microbiomes.

Posted in community ecology, genomics, natural history, next generation sequencing, population genetics, Uncategorized | Tagged , , | Leave a comment

Visualizing Linkage Disequilibrium in R

Patterns of Linkage Disequilibrium (LD) across a genome has multiple implications for a population’s ancestral demography. For instance, population bottlenecks predictably result in increased LD, LD between SNP’s in loci under natural selection affect each others rates of adaptive evolution, selfing/inbreeding populations … Continue reading

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d(N)eutralist < d(S)electionist Part 4

Continuing our discussion of the neutralist-selectionist debate, recent findings by Schrider et al. (2015) bring us to the topic of selective sweeps, and their genomic signatures in a population. As we have discussed in previous posts, numerous studies (since the … Continue reading

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Live fast and reproduce young

Here is one for the “simple, elegant science” folder: a new paper in PNAS by Julia Schroeder and colleagues that demonstrates a fitness disadvantage in offspring from older parents. While there a multitude of papers out there showing that gametes have … Continue reading

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How (not) to review papers on inclusive fitness

There are few evolutionary concepts as polarizing as Hamilton’s rule. Some researchers feel that there is no mathematical grounding for it, while others beg to differ. Yet empirical evidence in support of Hamilton’s rule is scarce (but check out this … Continue reading

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F-statistics Manhattan Plots in R

Characterizing differentiation across individual genomes sampled from different populations can be very informative of the demographic processes that resulted in the differentiation in the first place. Manhattan plots have grown to be very popular representations of genome-wide differentiation statistics in … Continue reading

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Killer genetic differentiation

Like most of you out there, I sometimes get bogged down in literature, and the pressure to keep up with new methods can lead to a towering “to-read” folder. I feel forced to read many of these papers no matter … Continue reading

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Haploid-diploidy, a (brief?) history

Haploid-diploid life cycles are not only good exercise for the brain, but they’re also fantastic study systems to investigate a myriad of questions. Yet, the majority of molecular studies have focused on the diploid-dominated life cycles of animal and plant … Continue reading

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dN(eutralist) = dS(electionist) Part 3

In a previous post, I discussed the phenomenon of background selection, which results in rapid expungement of neutral alleles linked to loci under purifying or negative selection, and conversely, the rapid fixation of neutral variants that are linked to loci of … Continue reading

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