Haplogroup S also known as S-B254 is a human Y-DNA haplogroup, defined by the SNPs B254 and Z33355. Until 2016, it was known as Haplogroup S1.
|Haplogroup Haplogroup S (M254)|
|Descendants||S1 (B255); S2 P378|
|Defining mutations||B254, Z33355|
S-M254 is the most common haplogroup among males in the Papua New Guinea Highlands. It is also relatively common in other parts of Oceania, South East Asia and among indigenous Australians.
In a major correction to the phylogenetic tree during 2016, Haplogroup S-M230 was "demoted" from the position of basal clade S*, becoming S1a1b, while S-B254 was "promoted" in its place to the level of S*.
It has two primary subclades: S1 (B255) and S2 (P378). The existence of a third subclade, defined by the SNP, P336 has not been confirmed.