Pontic steppes, along with the Indo-European languages; they also detected an autosomal component present in modern Europeans which was not present in Neolithic Europeans, which would have been introduced with paternal lineages R1b and R1a, as well as Indo-European languages. Studies which analysed ancient human remains in Ireland and Portugal suggest that R1b was introduced in these places along with autosomal DNA from the Pontic steppes. R1a and R1a1a The subclade R1a1a (R-M17 or R-M198) is most commonly associated with Indo-European speakers. Data so far collected indicate that there are two widely separated areas of high frequency, one in Eastern Europe, around Poland, Ukraine, and Russia, and the other in South Asia, around Indo-Gangetic Plain. The historical and prehistoric possible reasons for this are the subject of on-going discussion and attention amongst population geneticists and genetic genealogists, and are considered to be of potential interest to linguists and archaeologists also. A large, 2014 study by Underhill et al., using 16,244 individuals from over 126 populations from across Eurasia, concluded there was compelling evidence, that R1a-M420 originated in the vicinity of Iran. The mutations that characterize haplogroup R1a occurred ~10,000 years BP. Its defining mutation (M17) occurred about 10,000 to 14,000 years ago. Pamjav et al. (2012) believe that R1a originated and initially diversified either within the Eurasian Steppes or the Middle East and Caucasus region. Ornella Semino et al. propose a postglacial (Holocene) spread of the R1a1 haplogroup from north of the Black Sea during the time of the Late Glacial Maximum, which was subsequently magnified by the expansion of the Kurgan culture into Europe and eastward. Yamnaya culture According to Jones et al. (2015) and , autosomal tests indicate that the Yamnaya-people were the result of admixture between "Eastern Hunter-Gatherers" from eastern Europe (EHG) and "Caucasus hunter-gatherers" (CHG). Each of those two populations contributed about half the Yamnaya DNA. According to co-author Dr. Andrea Manica of the University of Cambridge: All Yamnaya individuals sampled by Haak et al. (2015) belonged to the Y-haplogroup R1b. Based on these findings and by equating the people of the Yamnaya culture with the Proto-Indo-Europeans, David W. Anthony (2019) suggests that the Proto-Indo-European language formed mainly from a base of languages spoken by Eastern European hunter-gathers with influences from languages of northern Caucasus hunter-gatherers, in addition to a possible later influence from the language of the Maikop culture to the south (which is hypothesized