As of 2017, it includes an unnamed primary subclade referred to by ISOGG as "S1a~" (P405),[1][2][3] (which was previously known as K2b1a). The "~" symbol is ISOGG's way of indicating that an unverified and as-yet unnamed immediate ancestor may exist.
Its secondary subclades include: S1a1 (Z42413), S1a2~ (P79, P307) and S1a3 (P315).
Before 2016, S1a1b (M230, P202, P204) was known as Haplogroup S* (and before that as Haplogroup K5). (In 2016, haplogroup S-B254 was "promoted" to S*, from its previous position of S1.)
The "sibling" clades of S1a include: S1b (B275, Z33756, Z33757, Z33758, Z33759), S1c (Z41926, Z41927, Z41928, Z41929, Z41930) and S1d (SK1806).
Haplogroup S1 (B255) includes the following subclades: S1a Z41335
S1a1 Z42413
S1a1a
S1a1a1 P60, P304, P308
S1a1a2
S1a1b M230, P202, P204 – "demoted" from its previous position as the basal Haplogroup S* (and known before that as Haplogroup K5)
S1a1b1 M254 (previously known as K2b1a4a)
S1a1b1a P57
S1a1b1b P61
S1a1b1c P83
S1a1b1d SK1891
S1a2 P79, P307
S1a3 P315
S1a3a Z41763
S1a3b~ P401
S1b~ B275, Z33756, Z33757, Z33758, Z33759
S1c~ Z41926, Z41927, Z41928, Z41929, Z41930
S1d SK1806
(Based on the 2017 ISOGG tree and subsequent published research.[1])
Distribution
Basal S1a* appears to be extremely rare or extinct in living males. The primary subclade S-P405* is also relatively rare, but is found at significant levels among various Micronesian populations: 5.6%. It is also found among males on the Indonesian island of Sumba at a rate of 0.2%.[4]
According to ISOGG (2017), S1a1 (Z42413) has been found among the Lebbo' people of Indonesia and S1a1a1 (P60) among indigenous Australians.[1] One study has reported finding S-M230 (S1a1b) in: 52% (16/31) of a sample from the Papua New Guinea (PNG) Highlands; 21% (7/34) of a sample from the Moluccas (Maluku); 16% (5/31) of a sample from the Papua New Guinea coast; 12.5% (2/16) of a sample of Tolai from New Britain; 10% (3/31) of a sample from Nusa Tenggara, and; 2% (2/89) of a sample from the West New Guinea lowlands/coast. One subclade, Haplogroup S1a1b1d1a (S-M226.1) has been found at low frequencies in the Admiralty Islands and along the coast of mainland PNG. [5][6]
The distribution of the other major subclades of S1a according to ISOGG,[1] is as follows:
S1a2 (P79) – Melanesia and Papua New Guinea, including the Admiralty Islands;
^ Cox MP, Mirazón Lahr M (2006). "Y-chromosome diversity is inversely associated with language affiliation in paired Austronesian- and Papuan-speaking communities from Solomon Islands". American Journal of Human Biology. 18 (1): 35–50. doi:10.1002/ajhb.20459. PMID16378340. S2CID4824401.
^Van Oven M, Van Geystelen A, Kayser M, Decorte R, Larmuseau HD (2014). "Seeing the wood for the trees: a minimal reference phylogeny for the human Y chromosome". Human Mutation. 35 (2): 187–91. doi:10.1002/humu.22468. PMID24166809. S2CID23291764.
^K-M2313*, which as yet has no phylogenetic name, has been documented in two living individuals, who have ethnic ties to India and South East Asia. In addition, K-Y28299, which appears to be a primary branch of K-M2313, has been found in three living individuals from India. See: Poznik op. cit.; YFull YTree v5.08, 2017, "K-M2335", and; PhyloTree, 2017, "Details of the Y-SNP markers included in the minimal Y tree" (Access date of these pages: 9 December 2017)
^ Haplogroup S, as of 2017, is also known as K2b1a. (Previously the name Haplogroup S was assigned to K2b1a4.)
^ Haplogroup M, as of 2017, is also known as K2b1b. (Previously the name Haplogroup M was assigned to K2b1d.)