mineral density, as opposed to other contemporaneous groups. Genetics Genetic studies of the Pitted Ware peoples has found them to have been strikingly genetically homogenous, suggesting that they originated from a small founder group. Already Malmström (2009) extracted mtDNA from seventeen Pitted Ware people of Gotland. Eight individuals belonged to U4 haplotypes, seven belonged to U5 haplotypes, one to K1a1, one to T2b, and one to HV0. The results debunked previous theories suggesting that the Pitted Ware were related to the Sami people. On the contrary, Pitted Ware people showed closer genetic kinship to modern Balts, Estonians, and modern Scandinavians. In a genetic study published in BMC Evolutionary Biology in March 2010, it was discovered that the Pitted Ware possessed a very low level (5%) of an allele (−13910*T) strongly associated with the ability to consume unprocessed milk. This frequency is dramatically different from modern Swedes (74%). Whether the increase of this allele among the Swedes was a result of admixture or natural selection was uncertain. In a genetic study published in Science in April 2012, an individual from the Pitted Ware culture was examined. The individual was found to have "a genetic profile that is not fully represented by any sampled contemporary population". In another genetic study published in Science in May 2014, the mtDNA of six individuals ascribed to the Pitted Ware culture was extracted. Four samples belonged to U4d, one belonged to U, and one belonged to V. A genetic study published in August 2014 found that Pitted Ware peoples were closely genetically similar to people of the Catacomb culture, who like the Pitted Ware people carried high frequencies of the maternal haplogroups U5 and U4. These lineages are associated with Western Hunter-Gatherers and Eastern Hunter-Gatherers. In a genetic study published in Nature in September 2014, members of the Pitted Ware culture were determined to largely belong to the Scandinavian Hunter-Gatherer (SHG) cluster. In a genetic study published in Proceedings of the Royal Society B in January 2015, the mtDNA of thirteen PCW individuals from Öland and Gotland was extracted. The four individuals from Öland carried H1f, T2b, K1a1 and U4a1. Of the ten individuals from Gotland, four carried U4, two carried U5 haplotypes, two carried K1a1, and one carried HV0. The results indicated that the Pitted Ware culture was genetically distinct from the Funnelbeaker culture, and closely genetically related to earlier Mesolithic hunter-gatherers of Scandinavia and