Overview
Haplogroup R-PF7562 is a deep and rare branch of R1b descending from R-L754, positioned phylogenetically between the earliest diversification of R1b and the later radiations of P297, M73, M478 and M269. PF7562 is a key upstream lineage that reflects early diversification in western Eurasia or Central Asia during the transition from the Upper Paleolithic to the early Holocene. Its existence shows that R1b’s ancient diversity was not limited to the well known European and Central Asian branches but included additional lines that left only faint signatures in modern populations. PF7562 is extremely rare today, and most occurrences documented in modern genetic studies represent basal or near basal lineages that survived in small regional populations. Despite its rarity, PF7562 is important for reconstructing the internal structure of R1b and understanding the demographic bottlenecks and founder effects that shaped its later expansions. This lineage helps complete the early branching topology between L278, L754 and the major downstream nodes such as P297. Because its time depth places PF7562 near the ancestral population structure of early Eurasian hunter gatherers, it is a valuable reference point for modeling the initial spread of R1b outside its place of origin.