possibly the source of the distribution of Indo-European languages in Europe. EHGs may have mixed with "an Armenian-like Near Eastern source", which formed the Yamnaya culture, as early as the Eneolithic (5200-4000 BC). Researchers have found that EHGs may have derived different amounts of their ancestry from WHGs and ANEs. Their relationship to the WHG and ANE is not well clarified. The people of the Mesolithic Kunda culture and the Narva culture of the eastern Baltic were a mix of WHG and EHG, showing the closest affinity with WHG. Samples from the Ukrainian Mesolithic and Neolithic were found to cluster tightly together between WHG and EHG, suggesting genetic continuity in the Dnieper Rapids for a period of 4,000 years. The Ukrainian samples belonged exclusively to the maternal haplogroup U, which is found in around 80% of all European hunter-gatherer samples. The people of the Pit–Comb Ware culture (PCW/CCC) of the eastern Baltic bear 65% EHG ancestry. This is in contrast to earlier hunter-gatherers in the area, who were more closely related to WHG. This was demonstrated using a sample of Y-DNA extracted from a Pit–Comb Ware individual. This belonged to R1a15-YP172. The four samples of mtDNA extracted constituted two samples of U5b1d1, one sample of U5a2d, and one sample of U4a. Günther et al. (2018) analyzed 13 SHGs and found all of them to be of EHG ancestry. Generally, SHGs from western and northern Scandinavia had more EHG ancestry (ca 49%) than individuals from eastern Scandinavia (ca. 38%). The authors suggested that the SHGs were a mix of WHGs who had migrated into Scandinavia from the south, and EHGs who had later migrated into Scandinavia from the northeast along the Norwegian coast. SHGs displayed higher frequences of genetic variants that cause light skin (SLC45A2 and SLC24A5), and light eyes (OCA/Herc2), than WHGs and EHGs. Members of the Kunda culture and Narva culture were also found to be more closely related with WHG, while the Pit–Comb Ware culture was more closely related to EHG. Northern and eastern areas of the eastern Baltic were found to be more closely related to EHG than southern areas. The study noted that EHGs, like SHGs and Baltic hunter-gatherers, carried high frequencies of the derived alleles for SLC24A5 and SLC45A2, which are codings for light skin. Mathieson et al. (2018) analyzed the genetics of a large number of skeletons of prehistoric Eastern Europe. Thirty-seven samples were