the following centuries saw a complete disappearance of both the Iranian and Turkic languages, indicating dominance of the Slavic language among the common people. Anthropology and genetics Genetic and anthropological researches have shown that the tribes of the Eurasian steppes were not always ethnically homogeneous, and were often unions of multiple ethnicities. Skeletal remains from Kazakhstan (Central Asia), excavated from different sites dating between the 15th century BC to the 5th century AD, have been analyzed. The distribution of east and west Eurasian lineages through time in the region agrees with available archaeological information. Prior to the 13th–7th century BC, all samples belong to European lineages, while later, an arrival of East Asian sequences that coexisted with the previous genetic substratum was detected. Hundreds of excavated mummies in the Tarim Basin (West China) have Caucasoid features, revealing the presence of an ancient Caucasoid substratum in East Asia. These findings are associated with the ancient Tocharians and Tocharian languages. According to P. Golden, the Central Asian Turkic peoples have multiple points of origin and are a mixture of steppes ethnic groups. Eric Hobsbawm considered the languages to be "almost always semi-artificial constructs". Political processes, rather than linguistic, tribal or ethnic elements, created new communities. Golden noted that the Turkic tribes in the Western Eurasia since the 1st millennium BC had contacts with Proto-Indo-Europeans. Those tribes were considered by Golden to be the ancestors of the Oğuric Turks. Recent blood and DNA studies of present-day populations in Central Asia confirm the extreme genetic heterogeneity. The latest DNA studies on Turkic people in Central Asia and Eastern Europe also confirm genetic heterogeneity, indicating that the Turkic tribal confederations included various mtDNA and Y-DNA haplogroups. A 2013 comparative genetic study shows that modern Bulgarians primarily are represented by the Western Eurasian Y haplogroups, with 40% belonging to haplogroups E-V13 and I-M423, and 20% to R-M17 (R-M198 and R-M458). Haplogroups common in the Middle East (J-M172, J-M267, and G-M201) and in South Western Asia (R-L23*) occur at frequencies of 19% and 5%, respectively. The central Asian and Altaic-Turkic haplogroups C, N and Q together occur at the negligible frequency of only 1.5% among Bulgarians. It could indicate that "a shared paternal ancestry between proto-Bulgarians and Altaic and Central Asian Turkic-speaking groups either did not exist or was negligible". However according to the Genetic Atlas of Human Admixture History by Hellenthal et al. 2014, using a