March 22, 2013

Y chromosomes and mtDNA from the Maldives

Of interest from the paper:

The haplogroup J(M304) Y chromosomes are all in subgroup J2(M172). 
However, Eaaswarkhanth et al. (2010) report that Muslims and non-Muslims in India largely have the same Y-haplogroup frequency distribution, except that in Muslims low frequencies of Y-E1b1b1a(M78), Y-J(M304)(xJ2(M172)), and Y-G(M201) are found that are absent in non-Muslims (Eaaswarkhanth et al., 2010). In our Maldivian sample, none of those Y-haplogroups were found.

AJPA DOI: 10.1002/ajpa.22256

Indian ocean crossroads: Human genetic origin and population structure in the maldives

Jeroen Pijpe et al.

The Maldives are an 850 km-long string of atolls located centrally in the northern Indian Ocean basin. Because of this geographic situation, the present-day Maldivian population has potential for uncovering genetic signatures of historic migration events in the region. We therefore studied autosomal DNA-, mitochondrial DNA-, and Y-chromosomal DNA markers in a representative sample of 141 unrelated Maldivians, with 119 from six major settlements. We found a total of 63 different mtDNA haplotypes that could be allocated to 29 mtDNA haplogroups, mostly within the M, R, and U clades. We found 66 different Y-STR haplotypes in 10 Y-chromosome haplogroups, predominantly H1, J2, L, R1a1a, and R2. Parental admixture analysis for mtDNA- and Y-haplogroup data indicates a strong genetic link between the Maldive Islands and mainland South Asia, and excludes significant gene flow from Southeast Asia. Paternal admixture from West Asia is detected, but cannot be distinguished from admixture from South Asia. Maternal admixture from West Asia is excluded. Within the Maldives, we find a subtle genetic substructure in all marker systems that is not directly related to geographic distance or linguistic dialect. We found reduced Y-STR diversity and reduced male-mediated gene flow between atolls, suggesting independent male founder effects for each atoll. Detected reduced female-mediated gene flow between atolls confirms a Maldives-specific history of matrilocality. In conclusion, our new genetic data agree with the commonly reported Maldivian ancestry in South Asia, but furthermore suggest multiple, independent immigration events and asymmetrical migration of females and males across the archipelago. Am J Phys Anthropol 000:000–000, 2013. © 2013 Wiley Periodicals, Inc.



hairysteve20 said...

If I recall correctly the Arab traveler and historian Ibn Battuta wrote about the Maldives and said that he entered into a temporary marriage with a local woman whilst there. This was apparently a custom in the islands at the time (14th Century).
That could explain the presence of west asian paternal admixture, that is Arab traders being given local wives for the duration of their stay on the islands.

terryt said...

"in Muslims low frequencies of Y-E1b1b1a(M78), Y-J(M304)(xJ2(M172)), and Y-G(M201) are found that are absent in non-Muslims"

Indicating these haplogroups are recent additions to the South Asian set.

SB said...

J and G are very much present in south asian non Muslims, and have been there for a long time. Extrapolating Maldives to all of South Asia (even south India) makes no sense. Look at table1 by arunkumar, wells To see what I mean.

Unknown said...

Absence of J1 clades suggests that J2 would have overwhelmingly come from south Asian mainland. Compare the results to Singalese Buddhists who have J2.

Unknown said...

Y-chromosome picture in Maldives.
R1a1 25%
R2 20%
J2 20%
Rest is H,L etc.
J1 absent. Means no Arab roots in Maldives contrary to some historical writings. This picture is very similar to sri lankan Sinhalese population.