male buried at Khvalynsk, Russia c. 7200-6000 BP carried R1b1a. A Neolithic male buried at Els Trocs, Spain c. 7178-7066 BP, who may have belonged to the Epi-Cardial culture, was found to be a carrier of R1b1. A Late Chalcolithic male buried in Smyadovo, Bulgaria c. 6500 BP carried R1b1a. An Early Copper Age male buried in Cannas di Sotto, Carbonia, Sardinia c. 6450 BP carried R1b1b2. A male of the Baalberge group in Central Europe buried c. 5600 BP carried R1b1a. A male of the Botai culture in Central Asia buried c. 5500 BP carried R1b1a1 (R1b-M478). 7 males that were tested of the Yamnaya culture were all found to belong to the M269 subclade of haplogroup R1b. R1b is a subclade within the "macro-haplogroup" K (M9), the most common group of human male lines outside of Africa. K is believed to have originated in Asia (as is the case with an even earlier ancestral haplogroup, F (F-M89). Karafet T. et al. (2014) "rapid diversification process of K-M526 likely occurred in Southeast Asia, with subsequent westward expansions of the ancestors of haplogroups R and Q". Three genetic studies in 2015 gave support to the Kurgan hypothesis of Marija Gimbutas regarding the Proto-Indo-European homeland. According to those studies, haplogroups R1b-M269 and R1a, now the most common in Europe (R1a is also common in South Asia) would have expanded from the West Eurasian Steppe, 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. Analysis of ancient Y-DNA from the remains from early Neolithic Central and North European Linear Pottery culture settlements have not yet found males belonging to haplogroup R1b-M269. Olalde et al. (2017) trace the spread of haplogroup R1b-M269 in western Europe, particularly Britain, to the spread of the Beaker culture, with a sudden appearance of many R1b-M269 haplogroups in Western Europe ca. 5000–4500 years BP during the early Bronze Age. In the 2016 Nature article "The genetic history of Ice Age Europe". Structure External phylogeny of R1b The broader haplogroup R (M207) is a primary subclade of haplogroup P1 (M45) itself a primary branch of P (P295), which is also known as haplogroup K2b2. R-M207 is therefore a secondary branch of K2b (P331), and a direct descendant of K2 (M526).