Polynesia category – Ancestry.com (part 2)

Last December I blogged an entry entitled Polynesia Category – Ancestry.com.  It was about their new Pacific Islander category and how I noticed Filipinos had been coming up with that category as well.  I have been noticing other people of mainly Southeast Asian ancestry having small percentages of Polynesia in their ancestry composition.

A Taiwanese aboriginal would have about the same amount as Filipinos, ranging around 25% – 29%.  A friend that I know whose mother is a Taiwanese aboriginal and he got DNA tested came up with 13% Polynesia and 37% Asia East.  That is nearly identical to what half Filipinos would get.  A Taiwanese person who has Fujian ties centuries ago and is not a Taiwanese aboriginal showed up having 8% Polynesia and 92% Asia East.  Another friend whose mother is from the Moluccas (Indonesia) and tested himself came up with 19% Melanesia, 12% Polynesia and 17% Asia East.  I have had three Chinese people who got tested with Ancestry.com and told me that they also had Polynesia show up within the 10% – 11% range.

All of these are the results of picking up that Southeast Asian component that exists for these people including Polynesians, of which makes up about 80% of their genome.  A few weeks ago I spoke to Ross E. Curtis, Ph.D., a computational biologist, specializing in genetics and visual analytics, and has been with Ancestry.com since 2012.  I informed him of the small sampling size that they had, just 18 samples (see Polynesia Category – Ancestry.com) and the problem that provided.  He was not too familiar with the details behind, mentioned a colleague that helped to put that category together but was unable to provide any real insight into that specific category.  So whatever I am learning about this comes from actual testees and especially those who are not of Polynesian ancestry.

My mother finally did test with Ancestry.com back in March when I made an emergency trip to Wai’anae, O’ahu, Hawai’i and had my mother retake that test since it got rejected.  I had predicted that she would basically show up as 80% Polynesia and 20% European, but this is her actual results.

 

It is as almost that Ancestry tends to give us the lowest possible amount of European.  I got 8% while my mother got 11%.  And just as it did with FTDNA’s myOrigins, it gave my mother a bit more  Scandinavian.  Actually with myOrigins my mother gets 19% while I show 11% Scandinavia.

We will probably see more people of Southeast Asian origin come up with the Pacific Islander/Polynesia/Melanesia category as a proxy for Southeast Asian as more get tested.

No surprise however when I looked at her matches, a lot of close 2nd – 3rd cousin matches.

 

My mother has three 1st – 2nd cousin matches, Extremely High confidence.  But for the 2nd – 3rd cousin range, she has sixty-seven matches, Extremely High confidence and a total of two-hundred sixty-seven matches for 3rd – 4th cousins, all Extremely High confidence as well.  Others not familiar with Polynesian endogamy, or endogamy in general insisted that these close matches have to be actual close matches.

I managed to match two of my mother’s 2nd – 3rd cousin matches on GEDmatch.com.  Assuming that the matches are listed in order of closest to the least closest, these are how the two matches up with my mother.

The 7th 2nd – 3rd cousin match:
510cM – total shared
26.9cM – largest segment

The 40th 2nd – 3rd cousin match (out of 67):
331.9cM – total shared
22.2cM – largest segment

These are one of the few larger segment matches that she has while most rarely go up to 15cM.  Something common with endogamous groups.  Only uploading to GEDmatch can it be clear if the 2nd – 3rd cousin matches are real 2nd – 3rd cousin matches, or an endogamous ones that has numerous segments rarely going higher than 15cM for the largest segment.  Other than that, any Polynesian testing at Ancestry cannot assume that the 1st – 2nd or 2nd – 3rd cousin matches are actually that close as estimated.