Haplogroup CR contains the M168 change, which is present in all Y-chromosome haplogroups except A and B and is therefore the common ancestral type of all early migration out of Africa as per the Single origin hypothesis. The mutation is believed to have occurred 31 to 55 thousand years before present within North East Africa.
^Haplogroup LT (L298/P326) is also known as Haplogroup K1.
^Between 2002 and 2008, Haplogroup T-M184 was known as "Haplogroup K2". That name has since been re-assigned to K-M526, the sibling of Haplogroup LT.
^Haplogroup K2a (M2308) and its primary subclade K-M2313 were separated from Haplogroup NO (F549) in 2016. (This followed the publication of: (2016) "Punctuated bursts in human male demography inferred from 1,244 worldwide Y-chromosome sequences". Nature Genetics '48' (6): 593–9. DOI:10.1038/ng.3559. PMID 27111036. In the past, other haplogroups, including NO (M214) and K2e had also been identified with the name "K2a".
^ Haplogroup K2b (M1221/P331/PF5911) is also known as Haplogroup MPS.
^ Haplogroup K2e (K-M147) was previously known as "Haplogroup X" and "K2a" (but is a sibling subclade of the present K2a).