tiistai 27. kesäkuuta 2017

Estonian Corded Ware enigma

The following simple dstat-figure shows the mystery of Estonian Corded Ware samples released during this spring.   There can't be any populational continuum from them to present-day Balts, including Estonians.  All thousands years older hunter-gatherer samples are overwhelmingly closer present-day Balts.  The change regarding HG ancestry can be seen in Western and Central Europe where we see a clear cut decrease of HG ancestry, obviously caused by increasing real Corded Ware and Bell Beaker ancestries.   We have to compare pure Neolithic populations against Estonian CW samples to reach parity in the Baltic area.  There is a tiny evidence about the given continuum;  Finns are closer German BA samples than Balts, giving a hint that there could be some subtle continuum.   

lauantai 24. kesäkuuta 2017

Yamnaya and Bell Beaker drift and ratio in present-day Europe

Following statistics gives an insight into how the Bronze Age Steppe ancestry transforms to a modern Northwest European genetic model and gives an idea of differences seen in Europe today.   I made free tests:

f3(Yamnaya Samara, X: Ju_hoan North)
f3(Bell Beaker Germany, X: Ju-hoan_North)
dstat(Bell Beaker Germany, Yamnaya Samara: X, Ju_hoan_North)

All results are based on around 450000 SNP's.

Results of F3_statistics were standardized to a common value 1 and also dstat-results were standardized separately to value 1.  The results show that a Yamnaya type ancestry is still significant in East Europe and the turning line from Yamnaya to Bell Beaker goes from Western Finland to Lithuania and Belarusia.   European farmer or Middle Eastern ancestry becomes dominant in South Europe leading to decreasing Bell Beaker ancestry in absolute terms.

lauantai 17. kesäkuuta 2017

Estonian Corded Ware was not Corded Ware

Despite of the common chronology the Corded Ware in Estonia was genetically a historical misstep if we believe dstat-statistics using samples of German Corded Ware and Bell Beaker cultures.  All Northern Europeans are closer German than Estonian samples.

torstai 15. kesäkuuta 2017

Shared drift with ancient Latvian, Estonian and British samples

Briefly said, shared drift of Latvian samples from Jones et al.   I have rebuild all samples using bam-files straight from the study and a new genotyping algorithm designed for ancient samples. 

perjantai 9. kesäkuuta 2017

British Viking Age samples placed on the genetic map

I got recently new samples from quite a new study, link here.   It looks more like a technical test than actual sampling for a purpose to study history, but anyway I sampled the data.  So far I have available eleven Viking Age samples from UK and have now tested them.   The data consist of around ten samples from each population, with exceptions of Swedes.  Only two Swedish samples were available for my mega-snp data base, both from the study "Genomic analyses inform on migration events during the peopling of Eurasia" (Luca Pagani 2016). The first one was from Nyköping, the second was without any place declaration.

The PCA lacks of a few Viking Age samples due to being too bad thus canceled by the outlier check.   British Viking Age samples look like to be German, but I should remind that PCA is based on dedicated components rather than genetic similarity in basis of the whole genome.   Let's see how those samples look in a formal analysis.  I have made several tests to give different views, for the reason that populations don't place in tests on one or two dimensional axis.

We see that in formal tests Swedes are closest to British Viking Age samples, followed by Irish and Scottish samples.  One straightforward conclusions could be that those Viking Age people were mixed Scandinavians and Celts/Britons. One bizarre remark:  Swedish samples are on the PCA prone to bias towards Finns and Norwegian samples show less this kind of similarity.  Still Swedish samples are closer those Viking Age samples from UK.   I have not tested this curio using formal analyses, but as far as I know this will be true in all tests.

edit 11.6.2017  12:50

German samples are from Leipzig.