in the preceding Yamnaya culture. Haplogroups U5 and U4 are typical of Western Hunter-Gatherers and Eastern Hunter-Gatherers. Moreover, a generic similarity between Catacomb people and northern hunter-gatherers, particularly the people of the Pitted Ware culture of southern Scandinavia, was detected. It was suggested that the Catacomb people and the Yamnaya people were not as genetically admixed as previously believed. Interestingly, the modern population of Ukraine was found to be more closely related to people of the Yamnaya culture than people of the Catacomb culture. Similarly, Nikitin et al. (2017), and Juras et al. (2018) found haplogroup U5 and U5a. These and other subclades of haplogroup U have been found in high frequencies among early hunter-gatherers of Northern Europe and Eastern Europe. From the Mesolithic they appear among populations of the Pontic steppe, including the Sredny Stog culture, the Yamnaya culture, the Corded Ware culture, the Andronovo culture, the Srubnaya culture and the Scythians. This suggests continuity of mtDNA among populations of the Pontic steppe going back at least to the Bronze Age. In a genetic study published in Scientific Reports in 2018, the remains of two individuals from the Catacomb culture were analyzed. Both were found to belong to haplogroup X4. They are the first ancient individuals that have been identified with this lineage, which is very rare among modern populations. In a February 2019 study published in Nature Communications, the remains of five individuals ascribed to the Catacomb culture were analyzed. Three males were found to be carrying R1b1a2. With regards to mtDNA, all five individuals carried various subclades of haplogroup U (particularly U5 and U4). Linguistics David Anthony (2007: 306) assumes that the Catacomb culture was Indo-European-speaking. It has sometimes been considered ancestral to Indo-Iranian or Thracian. Other scholars have suggested that the culture provided a common background for Greek, Armenian and Indo-Iranian. Successors The Srubnaya culture was a successor of the Catacomb culture. It has been suggested that the Abashevo culture was partially derived from the Catacomb culture. Parts of the area of the Catacomb culture came to be occupied by the Abashevo culture, and later by the Srubnaya culture. The Multi-cordoned ware culture was an eastern successor of the Catacomb culture. It in turn may have played a role in the emergence of the Potapovka culture and the Sintashta culture, and thus on the formation of the Andronovo culture. Morphological data suggests that the Sintashta culture