Downloading and Converting AADR v66

Recently, in April 2026, new AADR versions were released on Harvard Dataverse. Among the more important additions are the new compatibility datasets introduced for reducing platform-specific bias when co-analyzing ancient DNA generated with different experimental setups. This matters when combining data produced with different capture reagents such as Agilent (AG), Twist (TW), and shotgun (SG), because these can introduce systematic differences that may affect downstream population genetic analyses. The compatibility panels were added to minimize that problem and make mixed-platform datasets more directly comparable. ...

April 17, 2026

SmartPCA Tutorial: How to Run PCA on Genetic Data (EIGENSTRAT)

This post is a continuation of the previous one, where I demonstrated how to perform PCA with PLINK. While PLINK’s PCA is great for quick, exploratory analysis, smartpca (part of the EIGENSOFT toolset) is more commonly used in published genetic studies. Smartpca needs to be compiled on Linux or macOS, or alternatively installed via conda. I covered both methods in this earlier post: From EIGENSTRAT to PACKEDPED. As before, I’ll use a small subset. The focus here is on the technical process. One key difference in this post is that I’ll perform Linkage Disequilibrium (LD) pruning, which helps reduce SNP redundancy and improves the detection of population structure in PCA. ...

July 30, 2025