Overview
Haplogroup R-V45 represents one of the most important early branches within haplogroup R and is positioned immediately upstream of the split that later produced R1 and R2. This places V45 at a crucial junction in Eurasian paternal evolution, marking the demographic and genetic environment in which the earliest lineages of R diversified. The timing of V45 corresponds to the period directly after the formation of R-M207, when populations of the Eurasian steppe, the central Asian highlands and regions bordering the Iranian plateau were undergoing significant shifts due to the climatic oscillations of the late Upper Paleolithic. R-V45 likely belonged to a broad set of foraging groups living across northern and central Eurasia. These groups formed the ancestral pool that later differentiated into the major R1 and R2 macroclusters. Although V45 appears rarely as a basal lineage today, its placement in the phylogeny reveals a complex early history for haplogroup R, one involving ancient expansions, bottlenecks and founder dynamics long before the Holocene. The rarity of R-V45 in modern populations reflects the subsequent dominance of its daughter branches R1 and R2, which overshadowed the earlier structure. Nevertheless, as an essential intermediate node between R-M207 and the origins of R1 and R2, V45 provides key resolution for reconstructing the deep splits that define the R lineage.