Dating in west europe

05 Jul

As a result, based on phylogeny as Supplementary Fig.

S1, Dai from southern China could be considered to be a surrogate of ancestral EAS (Fig. Similarly, we applied our approach for each pair of EUR and found French holds the less genetic contribution from EAS than other EUR, and therefore can be considered as a surrogate of ancestral EUR (Fig. We assumed a Hybrid Isolation (HI) model for admixed Eurasian populations with ancestries from both EUR and EAS, as shown in Supplementary Fig. For each group of EAS, we assessed whether the statistic f), significantly deviates from zero (see Methods). Otherwise, the population should have entire EAS ancestry.

These studies reported the Asian or American contribution in European populations.

But the European gene flow in Asians has not been well studied yet.

Here we present what is, to the best of our knowledge, a systematic investigation of genetic admixture between different European and Asian populations using genome-wide single nucleotide polymorphism (SNP) data from 34 populations, including seven European groups (EUR), 9 Central or South Asian groups (CSA), and 17 East Asian groups (EAS) and one Tibetan group from Tibet Plateau.

Based on statistical analysis using 4 Population Test (f, we detected gene flow between Europeans and Asians were prevalent for most populations including even those from west-northern Europe and East Asia which have been generally regarded as less admixed.

To study the signal of gene flow between West and East Eurasian populations (European and Asian populations in Table 1), firstly we performed Principal Component Analysis (PCA) both with and without respectively African populations based on 96,538 random SNPs avoiding high linkage disequilibrium.

We observed that some clusters of West and East Eurasians are slightly shifted towards each other, indicating potential admixture between them (Fig. There is a clear ‘cline’ between West and East clusters.

Different from other CSA, Makrani showed significant signal of African ancestry. To estimate the genetic contributions of EUR and EAS ancestries, we first performed a linear regression procedure, which assumes that mixed populations share similar demographical histories.

An estimation of admixture proportions for each EAS is provided in Table 2.

We detected 2.8 ± 0.2% EUR ancestry in Northern Han Chinese (CHB), which was more than that in Southern Han Chinese (CHS; 1.7 ± 0.1%), Japanese (2.2 ± 0.2%) and Korean (1.6 ± 0.2%) populations.

In the current study, our samples did not cover all European regions.

For example, Southern European populations were not included in the analysis because they may have been affected by a recent genetic contribution from populations with African ancestry.