Overview
Haplogroup R-P224 is a very early and extremely rare branch of haplogroup R that diverged soon after the formation of R-M207 but before the major separation of R into R1 and R2. This lineage is part of the deep ancestral structure of R and helps define the phylogenetic landscape of Upper Paleolithic populations in Eurasia. Because P224 did not participate in the large demographic events that shaped later Eurasian genetic history, it survives today only in very limited and scattered forms. The formation of P224 coincides with a period of climatic instability in northern Eurasia, when human populations were small and highly mobile. Groups carrying P224 likely formed part of the broader meta population from which the more successful R1 and R2 radiations eventually emerged. Although P224 may have been more widespread in the past, its minimal modern presence suggests historical bottlenecks or replacement by expanding populations during the Holocene. From a phylogenetic standpoint, R-P224 is essential because it demonstrates that haplogroup R once possessed a much more complex and diversified structure than is visible in modern populations. Including upstream ghost branches such as P224 helps reconstruct the full scope of early Eurasian paternal diversity.