Category Archives: software

Estimating the ticks and tocks of molecular clocks

M Like many undergraduate students, I learned about the linear, universal molecular clock: the homogeneous rate of nucleotide change over time. When I sat down to actually do analyses of molecular data, I was confounded by the array of options to treat … Continue reading

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Posted in evolution, Molecular Ecology, the journal, mutation, software | Tagged | Leave a comment

The imitation game: simulating the genetics of large populations

Computational simulations of genetic data are such a powerful and flexible tool for carrying out studies in molecular ecology. Do you want to know how much explanatory power your data provides? Simulate it! Predict the future response of species to … Continue reading

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SpaceMix, and a brief history of Spatial Genetics

Incorporating spatial data to inform studies of the population demography of a species has a long history of interest. From inferring geographical clines in Principal Components Analyses (Menozzi et al. 1978), using location data as “informative priors” during model-based estimation … Continue reading

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A population genetic R-evolution

Uphill, both ways, in the snow, without shoes … quite apt when thinking of the dark days, in the not too distant past, in which a separate input file was needed for each popgen analysis in order to use a … Continue reading

Posted in howto, methods, population genetics, R, software, Uncategorized | Leave a comment

haploidy, diploidy, polyploidy … not a problem

Investigating pairwise relatedness is fundamental to the characterization of the mating system and inferring genetic structure. If no pedigree exists, then relatedness is estimated from genetic markers (e.g., microsatellite loci) using method-of-moment or maximum-likelihood methods. However, not all individuals in … Continue reading

Posted in natural history, pedigree, population genetics, software, Uncategorized | Leave a comment

Migration Circos plots in R

We’ve all seen them – colorful, and I daresay, pretty darn informative. Circos plots are fun visualizations of large data-sets. I’ve seen them used in two contexts in comparative genomics – to represent structural variants in homologous chromosome segments in … Continue reading

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Geophylogeny plots in R for Dummies

Amid basting my tofurky, here’s a follow-up to my previous post on quick-fix overlays of admixture plots on geographical maps in R. I recently discovered a wonderful R package called “phytools” from Liam Revell, which makes really neat phylogenetic trees (with … Continue reading

Posted in howto, phylogenetics, population genetics, R, software, STRUCTURE | Tagged , | 2 Comments

The latest gadget for the molecular ecologist’s toolkit

Designing a sampling scheme to collect an organism of interest for a population genetic/genomic study can be fraught with difficulty. How best to sample? Randomly? Or, along a grid? How many individuals to sample? Thirty? Or, perhaps, the sample size … Continue reading

Posted in genomics, methods, Molecular Ecology, the journal, natural history, pedigree, population genetics, software | 1 Comment

Admixture maps in R for Dummies

Before we get started, I’d like to point everyone to an excellent tutorial here by Kim Gilbert on making maps in R. I have been grappling with overlaying admixture plots, and migration routes on top of maps recently, and thought I’d put … Continue reading

Posted in howto, population genetics, R, software, STRUCTURE | Tagged , | 11 Comments

How many markers does it take to make a dataset “genomic”?

A new paper in Ecology Letters by Matthew Fitzpatrick and Stephen Keller proposes to use some a class of statistical methods developed for understanding the distribution of species in different environments to understand the distribution of genetic variants in different … Continue reading

Posted in association genetics, genomics, next generation sequencing, population genetics, software | 6 Comments