lauantai 10. helmikuuta 2018

New Baltic samples on PCA plots

I have made two PCA plots using new Baltic samples published by Mittnik et al. 2018, but as far as I can see with a different approach.  On my plots modern populations are placed at first hand on grounds of ancient samples, giving, in my humble opinion, a historically correct approach.  I have also standardized  sample sizes of modern populations to minimize the effects of modern genetic drift, which of course, if exists, will lead to comparison error due to irrelevant PCA-components.  Thirdly I have here two regional view; Eurasian and European.  The Asian effect on the Eurasian picture is pronounced in certain modern populations implying Asian admixture events after the Bronze Age Europe.


Eurasian picture:


Close-up of Eurasian picture:



European picture:


edit 10.2.2018

On the Eurasian picture the first dimension (X) represents East-Asian and Siberian maximums and the second one (Y) represents ancient farmer maximum.  So the picture isn't relevant for checking dimensions inside present-day Europe.  It is easy to understand that the flat left represents Asian/Siberian minimum regardless of later European structures.  Similarly the the vertical axis represents variation between ancient farmers and hunter-gatherers rather than structures inside present-day Europe.   The third picture (Europeans only) represents historically correct variation between ancient farmers and hunter-gatherers and exclusively to these variations ancient Steppe populations.  





keskiviikko 7. helmikuuta 2018

New Baltic samples in comparison to present-day populations

A large amount of new ancient samples are published by Mittnik et al 2018.
I compared those samples against modern local populations using F3-statistics (qp3Pop) using Chimp as the outgroup to eliminate even smallest impact of African/Near Eastern gene flow after the OOA event.   F3-scores were divided by a constant value giving results below 10.












Some ancestral changes in Iron Age Estonia

QpAdm was designed to detect admixtures giving also probability and standard error statistics.  Two kind of parameters are inputted: admixtu...