Methodology deep-dives, population spotlights, and engineering notes from the Ancestrify team, qpAdm modelling, ancient DNA panels, and how genetic ancestry analysis really works.
24 stories
What a Global25 PCA projection shows, what the axes are and are not, why plot distance lies, the difference between projecting onto a fixed view and fitting your own — and the honest uses of both.
A Global25 model and a testing company's ethnicity estimate answer different questions with different references and different time depths. What each is actually computing, and which to trust for which claim.
Everything you can do with a Global25 row without paying anyone: distance rankings, admixture fits, PCA plots, averaging, authenticity checks — Vahaduo, nMonte and the Ancestrify Lab, honestly compared.
Dante Labs, Nebula, Sequencing.com and other WGS files can become official Global25 coordinates — via the portal's own conversion surcharge or a free WGSExtract conversion. What each route costs and where the traps are.
What a Global25 distance ranking actually measures, why era choice changes everything, how close is 'close', and the four misreadings that turn a good tool into a wrong conclusion.
From the Eurogenes blog's admixture calculators through Global 10 to the 2018 launch of Global25 — why a 25-dimension PCA became the ancestry community's common currency, and what changed around it since.
Every admixture calculator — GEDmatch's classics, Global25 fits, testing-company estimates — is an optimiser that cannot say no. How the three families work, what the percentages mean, and the questions a calculator can and cannot answer.
Which GEDmatch admixture project to run for your background, what each calculator's components mean, why the projects disagree with each other, and what has aged since 2012–2016.
There is no single best admixture calculator — there is a best one per question. An honest decision guide across GEDmatch's classics, Global25 tools and formal methods, from someone who builds one of them.
Accuracy has three different meanings for an ancestry calculator, and the tools do well on exactly one of them. Where percentages are trustworthy, where they are noise, and how to tell which regime you are in.
The same genome scores 44% North European in one calculator and 51% in another. Component anchoring, reference panels, the calculator effect and K explain the spread — and none of the numbers is 'the real one'.
Oracle ranks reference populations by how closely their calculator percentages match yours — not by shared DNA. How the distance is computed, what single and mixed modes tell you, and the misreadings to avoid.
The thirteen K13 components, what North Atlantic, East Med and West Asian are anchored to, who the calculator works best for, how to read the Oracle — and the caveats that come with a 2012-era tool.
What the 36-component Eurogenes calculator can genuinely show, why its regional labels invite over-reading, what a K36 heat map is actually plotting, and when a distance ranking answers the question better.
The original admixture project's most-used calculator: what the twelve K12b components are anchored to, what Gedrosia and Caucasus mean in modern ancient-DNA terms, and how to read a K12b breakdown.
What HarappaWorld's S-Indian, Baloch and NE-Euro components are anchored to, why it remains the reference calculator for South Asian ancestry, and how its 2012 categories map onto what ancient DNA later proved.
The program behind the bar plots in population-genetics papers: how ADMIXTURE estimates K components jointly from all samples, supervised versus unsupervised runs, choosing K, and why hobbyist calculators are its frozen shadows.
A calculator against modern populations answers 'who do I resemble today'; one against dated ancient samples answers 'which deep ancestries formed me'. Mixing up the two produces the classic misreadings.
GEDmatch's admixture calculators froze around 2012–2016. The free alternatives that run on current ancient reference panels — era-scoped calculators, distance rankings, PCA — and what each replaces.
A step-by-step qpAdm tutorial: check your raw file, merge it into AADR v66, choose sources and outgroups, run it in the browser or in R, and read the result.
Every place that sells or offers qpAdm in 2026: hand-checked analyses, DIY tools and subscriptions, with inputs, reference data and price models side by side.
What a qpAdm analysis costs in 2026: four one-time tiers from 29.99 EUR, the add-ons, what does not change the price, and what a DIY subscription costs instead.
What Davidski's Eurogenes G25 Requests portal is, what you upload, the scaled and unscaled rows you get back, their stated fee, and what to do with the row next.
What an admixture calculator optimises, why it always answers, what a qpAdm model adds, when each is the right tool, and when qpAdm is not worth paying for.