Sunday, November 30, 2014
Monday, September 8, 2014
Update 01/01/2015: ANE is the primary cause of west to east genetic differentiation within West Eurasia.
As its name implies, the Eurogenes ANE K7 is specifically designed to estimate Ancient North Eurasian (ANE) ancestry. It's based on a series of supervised runs with the ADMIXTURE software, and freely available at GEDmatch under the Eurogenes Ad-mix tests tab.
The ANE component is not modeled on the Mal'ta boy or MA-1 genome, the main ANE proxy in scientific literature, because this sample didn't offer enough high quality markers for the job. So instead, I used the non-East Asian portions of several Karitiana genomes from the HGDP.
I wasn't sure what was going to come of that, but it actually seems to have worked out really well. Below are the results for several individuals that were not used in the making of the test, and clearly their ANE scores look pretty damn solid going by recent papers. For instance, both Lazaridis et al. and Raghavan et al. estimate the Karitiana Indians at just over 41% ANE (see here and here).
Karitiana_HGDP00998You can also cross-check your ANE score with the results in this spreadsheet and table. The spreadsheet includes ANE estimates for more than 2,000 individuals that I tested with the ADMIXTURE software in supervised mode (see here).
On the other hand, the table comes from the Lazaridis et al. preprint, which I'm sure many of you have read by now several times over. And please pay attention to the range of ANE proportions for each population, rather than just the point estimates.
Obviously, there are also six other ancestral components in this test (hence the K7 in the name). They're basically byproducts of me trying to isolate ANE, and don't necessarily mean anything. Nevertheless, here's a brief rundown of what I think some of them might represent...
Ancestral South Eurasian (ASE): this is a really basal cluster that peaks in tribal groups of Southeast Asia. It's probably very similar in some ways to the Ancestral South Indian (ASI) component described by Reich et al. a few years ago.The other three components should be easy to work out from their names. They're almost identical to several components with the same or similar names from my other tests.
Western European/Unknown Hunter-Gatherer (WHG-UHG): this essentially looks like a West Eurasian forager component, and includes the forager-like stuff carried by Neolithic farmers (Oetzi the Iceman has 40% of it).
Early Neolithic Farmer (ENF): I'd say that this is the component of the earliest Neolithic farmers from the Fertile Crescent.
Some of you might be wondering why this test doesn't offer an Early European Farmer (EEF) cluster. But the answer to that should be obvious by now. EEF is not a stable ancestral component. It's actually a composite of at least two ancient components, including the so called Basal Eurasian and WHG-UHG. If it really was a genuine ancestral component, like ANE, then I'm pretty sure I'd be able catch it with ADMIXTURE. But I can't.
Indeed, a really important thing to understand about the Lazaridis et al. study is that it doesn't actually attempt to estimate overall WHG-UHG ancestry in Europeans, but rather the excess WHG-UHG on top of what is already present in the EEF proxy Stuttgart.
Also worth noting is that this K7 can be a bit noisy. That's mainly because it's very difficult to correctly assign proportions of ancient ancestry to present-day samples. But like I say above, this test is basically designed to estimate ANE scores. If you're wanting to learn about your overall ancestry then I recommend the Eurogenes K13 and K15 tests.
Missing SNPs might also be an issue for some people. It stands to reason that results will be noisier with more missing markers and no calls.
Have fun and don't forget to make a donation at some point to the Eurogenes cause, via the PayPal tab at the top right of the page. This will help me to keep up with what's going on in the world of Paleogenomics, and continue blogging and running analyses.
Iosif Lazaridis, Nick Patterson, Alissa Mittnik, et al., Ancient human genomes suggest three ancestral populations for present-day Europeans, arXiv, April 2, 2014, arXiv:1312.6639v2
Raghavan et al., Upper Palaeolithic Siberian genome reveals dual ancestry of Native Americans, Nature, (2013), Published online 20 November 2013, doi:10.1038/nature12736
Corded Ware Culture linked to the spread of ANE across Europe
Wednesday, July 16, 2014
Update 12/05/2015: 4mix: four-way mixture modeling in R
This is really easy and should work well for most personal genomics customers (ie. those of European ancestry and with data files from 23andMe, FTDNA and AncestryDNA).
First of all, make sure you have your Eurogenes K15 ancestry proportions from GEDmatch. Then do the following:
- download the 4 Ancestors Oracle (here)
- download the Eurogenes ancient genomes datasheet (here)
- place everything into the same directory
- double click of the 4 Ancestors Oracle icon (the big red number 4)
- select the Eurogenes K15 ancient genomes datasheet
- type your Eurogenes K15 ancestry proportions into the fields provided
- hit the go button and let it rip
I'm not sure I'm allowed to upload the 4 Ancestors Oracle online, but I couldn't find the original link, so let's assume for the time being that I am. In any case, many thanks to Alexandr Burnashev for this great tool.
You'll also find some modern populations in the datasheet. They're there so that users with ancestry from outside of Europe don't end up with ridiculous results.
Obviously, you can edit the datasheet to explore more options by removing or adding individuals and populations. A spreadsheet of Eurogenes K15 population averages is available here. The oracle settings can also be tweaked in a couple of ways to fine tune the results.
If the calculator crashes, try replacing the periods with commas in both the datasheet and your ancestry proportions.
Please keep checking this post, because I'll attempt to update the datasheet at the link above every time a new ancient genome is published and has enough markers available to be tested with the Eurogenes K15. Eventually we might end up with a tool that covers most of the continents and many periods of history and prehistory.
I've done similar analyses of a variety of ancient genomes. For instance, StoraFörvar11, or SfF11, from Mesolithic Sweden came out 3/4 La Brana-1 and 1/4 MA-1, which translates to 3/4 Western European Hunter-Gatherer (WHG) and 1/4 Ancient North Eurasian (ANE), and lines up well with results reported recently for Swedish hunter-gatherers in scientific literature. You can see the full analysis StoraFörvar11 and a couple of other ancient genomes at the links below.
Analysis of Mesolithic Swedish forager StoraFörvar11
More ancient genomes from Sweden: Pitted Ware forager Ajvide58 and TRB farm girl Gokhem2
I'm still trying to answer a whole lot of e-mails so I won't be monitoring this post for a while. But please feel free to share your results and any tips you might have in the comments below.