Ancestry is finally showing Longest Segment size

I have been waiting and have asked Ancestry for this a few years ago.  Apparently, I was not the only person of an endogamous background who had asked for it.

I went through my list looking for the first known Maori, just to see how large the longest segment would be.  I have always advised Polynesians to look for anything at least 30cM for the largest segment (longest block at FTDNA) or as Ancestry is calling it, longest segment size in order to determine a true 2nd to 3rd cousin relationship.  I know with other endogamous groups they tend to look for something around 20cM.

At Ancestry, you will have to click on that match’s name in order to see the longest segment size.

Notice how the longest segment size is below 20cM, but based on the total amount shared the predicted relationship is anywhere between a 2nd – 3rd Cousin.  To show you what that looks like against known 2nd to 3rd cousin relationships, I am showing my match list about where the endogamous matches come in.  I indicate the Hawaiian ones versus the Maori ones and my known cousins.  I am inserting the longest segment size since you cannot initially see it on your list until you click on the match.

While I have a lot of 3rd cousin matches, my mother and one of my cousins have a lot of 2nd cousin matches.  My cousin had over 500 of 1st – 2nd Cousin predicted relationships.   Just looking at her top matches, I indicated the known relationships versus any Maoris and Hawaiian that she matches.

This definitely will help with determining the endogamous matches.  But the longest segment size does get smaller the more distant of the relationship becomes.  So by the 3rd to 4th cousin level, you may not really be able to tell, with the exception of the fact that we tend to get a lot more segments.

I have a 2nd cousin of whom we do not share a lot of DNA.  While we still share in the range of what is expected for a second cousin, the longest segment size is just over 20cM.

 

At least sorting through these matches have become easier now that we have this additional feature.  Again, this works well with the closer predicted relationships.  This may not be as useful if you already have a lot of distant matches and your Polynesian matches fall within that range.  A lot of my western Polynesian (Samoans and Tongans for example) matches are in that range.

Below are some of my Samoan matches and while their total shared is not a whole lot, their longest segment size is significantly smaller compared to what we normally see with eastern Polynesians.  This is true with other DNA companies like FTDNA and 23andme.

My top FTDNA matches where the endogamous matches come in among my known relationships.

I am hoping that in the near future Ancestry will put the longest segment size immediately on the match list page so it will be easier to go through rather than click on each name to see if the match really is worth looking into.    For now, what we have is definitely an asset to help us sort through these matches.

More Genetic Communities at AncestryDNA

Finally, after asking AncestryDNA to split their Genetic Communities at least into 2 main regions (eastern Polynesia vs. western Polynesia, they come up with a major update, not just for Polynesians but for other places in the Pacific Islands, Asia, and America.

The former “Hawaii, Tonga & Samoa” genetic community has been broken into 4 different communities.

The maps that go with these genetic communities are not the best given how small these islands and atolls are on the map.  Not to mention how distant one island nation is to the next, especially when you see how AncestryDNA decides to group them together.

The Polynesian Islands genetic community is basically the same map that they had for the former Hawaii, Tonga & Samoa genetic community.

The Cook Island & French Polynesia genetic community covers a vast area.  But the area covered is nothing like comparing the distance between New Zealand & Hawaii.

The Hawaii & New Zealand genetic community basically just highlights the remaining extreme points of the Polynesian triangle (minus Easter Island), with Hawaiʻi to the north and New Zealand to the southwest.

The broader Hawaii, Tonga, Samoa, Fiji & New Zealand genetic community’s map does not even zoom in.  You will have to zoom in to see a better view of the islands within this genetic community.

And finally, the Tonga, Samoa & Fiji genetic community would also include other western Polynesian islands like Niue, Tokelau, and Tuvalu.  What is interesting, although it is no surprise, that they also included Fiji into this group.  Historically Fiji had some role with initial populating of Remote Oceania.  I have seen a few Fijian matches not just for me but also with my mother and cousins.

It would be nice if in the future they really can fine-tune these genetic communities a bit more.  While we know that eastern Polynesian people come from western Polynesia centuries ago, those of us from Hawaiʻi, Aotearoa (New Zealand) and Rapa Nui (Easter Island) know that we had ancestors coming from what is known as French Polynesia (Tahitian archipelago and the Marquesas) as recent as 800 years ago.

So while I did not get the French Polynesia (with Cook Islands) community, my mother did.  She does have more matches with western Polynesians (Samoans and Tongans) than I do.  She also has more matches with Fijians than I do, so I am not surprised she got the Tonga, Samoa & Fiji and also the Hawaii, Tonga, Samoa, Fiji & New Zealand genetic communities.

We will see as time goes by how my own genetic communities get updated.

Ancestry updates their ethnicity yet again

As of November 13, 2019, everyone’s AncestryDNA results were updated.  Back in late October, only a few people have been getting the new update and all new testees.  Now we are all on the same page.

They did several changes which include increasing the number of genetic communities for various populations, increasing the size of their reference samples, renaming of categories and adding in a few new categories such as Guam, Samoa and Tonga.

We are going to concentrate on Samoa and Tonga, which they attempted to split off from the rest of Polynesia.

When AncestryDNA created the Polynesia category back in December 2013, it only consisted of 18 Polynesian samples which included at least one (or possibly more) of the samples that have distant European ancestry.  They updated their category and rolled out the new update to everyone back on September 12, 2018 with an additional 40 more samples increasing to a total of 58 for Polynesia.

In June and December 2018, I had the opportunity to speak to David Turissini, Ph.D who is a population geneticist at AncestryDNA.  I expressed my concerns with him regarding more specific categories among Polynesians.  Basically splitting eastern from western Polynesia.  I also explained why I thought that would be much better for us particularly for matching as we all tend to match each other at a very closely predicted relationship.  And that I thought the low number of reference samples could possibly affect the way we get our results.

He told me that I already understood how Polynesians lack genetic diversity so increasing the number of samples would not make any difference.  But then I pointed out how it was not that difficult for me to distinguish a western Polynesian (Samoan, Tongan, Tokelau, Tuvalu) versus an eastern Polynesian (Maori, Tahitian, Cook Island Maori, Hawaiian, Marquesan, Rapa Nui).

Despite all that was said, I was surprised to see how they increased the number of reference samples for Polynesia along with adding in Samoa and Tonga.

New categories & increase of samples for Polynesia

You can read more about it here:

https://www.ancestry.com/cs/dna-help/ethnicity/estimates

So their reference samples of 16,638 has increased by 23,379 samples to a total of 40,017.  Of that amount, they added 130 more samples to the Polynesia category and creating Samoa with 73 and Tonga with 97 samples.

While I have not noticed a lot of Tongan results yet, I have seen several Samoans.  Most of the ethnicity results I have seen are either Hawaiians or Maoris.  For the most part, eastern Polynesians are getting either Samoa and/or Tonga in the range of 1% – 4%.  For Samoans, I’ve seen about 60% – 70% Samoa and the rest Tonga.  A few Cook Island Maoris seem to have a higher percentage of Samoa compared to other eastern Polynesians but that may be due to the fact that they have ties to Aitutaki or its neighboring islands versus Rarotonga.  Or maybe Cook Island Maoris just have a higher percentage because of another group of people that settled earlier and/or it could be due to the original people who just so happened were genetically more like Samoans.

This whole classification, while it cannot be accurate as it is nothing but an estimate, really makes it interesting and gives us a bit more of an insight as to the settling of Polynesia.  Of course we can also see this as more people are getting Y-DNA tested and mtDNA and we slowly learn more about these different migration patterns which no surprise, confirms our oral histories.

My results have changed throughout time since I tested with AncestryDNA back in January 2014.  The biggest breakthrough came last year as they actually created the Philippines category which correctly allocated my Filipino side from Polynesia, therefore decreasing my amount.

But what does my tree look like compared to my current DNA results?

 

With the latest update it made my color scheme more difficult to accomplish but in the tree I do point out the foreigners.  While my father was born in Lahaina, Maui, Hawai’i, both of his parents were from the Visayas region in the Philippines.  For my maternal grandmother’s mother – Rose Holbron, her paternal grandfather was from Hull, England while her maternal grandfather was from Queens, New York, U.S.A.  And for my maternal grandmother’s father – Frank Kanae, he had distant American ties.  His great-grandfather Isaac Lewis Kanae was the son of Captain Isaiah Lewis.  I still have not pinpointed his origin yet.  And Isaiah Lewis’ father-in-law Oliver Holmes arrived in the Hawaiian Islands in 1793 from Plymouth, Massachusetts.  At the time Oliver Holmes left Plymouth, there were only 15 states in the U.S.A.

So what I did was place their ethnicities under a continental level and compared it to my DNA results, which all adds fairly nicely, taking in random inheritance.  My mother gets 17% European compared to her sister who gets exactly 15% which is consistent with the genealogy.  And in turn my mother gave not one but both of my brothers about half of her European – 8% and 9% for them while I ended up with the higher percentage – 11% which appears as about 11% – 12% at different testing companies.

And while I show 2% Samoa, my mother ended up with 1% of both Samoa and Tonga.

 

For my cousin who is not admixed, it was interesting to see, despite the erroneous genetic communities that would come up, how hers changed.  Because we match other Polynesians at a very closely predicted relationship, and the fact that my cousin is not admixed, she matches a lot of part Polynesian people who fall into a specific genetic community among others of whom she also matches.  So she ends up with the same genetic community.

 

 

With this latest update, they finally got rid of the Native American category for both my cousin and my mother.  But now with Samoa and Tonga, it is no surprise that they would give us a small percentage of that.  And having gone through several of these 1% – 2% categories of Samoa and Tonga, they all seem to range the same – 1% – 4%.  Interestingly for my mother, her range for Tonga was 1% – 3% while her Samoa was 1% – 4%.  But the way it ended up was both 1%.

I have also been witnessing those who previously had small amounts of Polynesia now being reclassified as Samoa, Tonga or Guam.  Usually, these are people with either Melanesia or some other Southeast Asian from various parts of Indonesia.  I would be really interested in seeing more results who have ties to that area.

So while I was told the number of increase of samples would not do anything, it obviously did quite a bit.  If only they would have renamed the Polynesia category by specifying Eastern Polynesia.  They should also do the same renaming their genetic community.  It would make more sense as we know that both Samoa and Tonga is part of Polynesia and of course, their map for Polynesia would include Samoa and Tonga within that area.  I would have expected western Polynesia as I mentioned to them versus eastern Polynesia, but they really got very specific.  And in the end result, Samoans will see that they are about 30% Tongan and probably the same for Tongans where they will see a smaller percentage of Samoa.  These people do get about 0% – 1% Polynesia in their results.

We will just have to wait to see what the future updates would bring.

Previous entries about AncestryDNA’s Polynesia category:

https://hawaiiandna.wordpress.com/2014/12/15/polynesia-category-ancestrydna-com/

https://hawaiiandna.wordpress.com/2015/06/30/polynesia-category-ancestry-com-part-2/

Largest Segment – Is it the best way to gauge the closeness of relationship?

In my earlier blog posts I have mentioned how significant the largest segment size is when determining a true 2nd to 3rd cousin relationship.  Polynesians can have a total shared amount that can easily exceed 100cM.   These totals tend to over-estimate the predicted relationships.

From the ISOGG Wiki’s page, you can see that the average for 2nd cousins once removed (2C1R) is 106cM while 2nd cousins are averaging around 212.50cM.

So we tend to get a lot of these 2nd – 3rd cousin matches, depending on the company you tested with.  This is why the largest segment size has become important.  Blaine Bettinger has a post entitled The Shared cM Project – Longest Shared Segment where people had submitted their longest segment size based on their known relationships.  You can compare 2nd and 3rd cousins there and see what the average is for the longest segment size for specific relationships.

A quick look at the type of numbers just by looking at my own ONE TO MANY from GEDmatch.com.

My cousin Allen who is a 2C1R to me (his maternal grandmother & my mother are 1st cousins) has a large segment of 35.9cM.  You can see more comparisons of the largest segment for 2nd to 3rd cousins from Blaine’s Shared cM Project but I also have been keeping my own numbers from my known relatives.

Only one of those 2nd cousins shared a large segment of 21.8cM, pretty small, and then it gets even lower as you go more distant.  But normally 2nd cousins will share a rather large segment, which is why more than 20cM has always been advocated and also among the Ashkenazi Jewish community.  In fact, I thought they used 25cM, but I could be wrong.  I even mentioned 30cM would be good.

But is it a requirement?  Absolutely not.  However, if you cannot find a connection, or the same geographical origin i.e. New Zealand or Hawaii, then that would be a strong indicator that you are not as closely related as it was predicted.

I have been noticing how I do have a few Hawaiians whose largest segment is more than 30cM but have not been able to find a connection.  I also notice that these matches will not have the same geographical origins as I do.  So could it be that these large segments remain in our population for many generations?

Here’s an example of how it actually has remained for centuries by comparing my Hawaiian mother and a Maori.

Taking my mother’s ONE TO MANY matches, I sorted them by the largest segment size.  I indicated the known relatives in blue and the unknown in red.  My mother has a Hawaiian match as 44.6cM for the largest segment.  I still have not been able to find a connection, although one of that match’s branch goes back to the area of a few of my ancestors.  But even for us, that was more than 3 generations ago from my mother.  Another at 39.9cM, not sure if that person is a Hawaiian or Maori.  And there is a Maori match with the largest segment of 25.9cM.   At FTDNA, there is a Maori match whose largest segment is 23cM.

Here is the largest segment sized match with a couple of Hawaiians from MyHeritage.

37.2cM and 33.6cM.  They have pretty good trees but their ancestry goes back to totally different islands from my own ancestors.  And I saw in their trees the origins of the different islands is further back while the more recent ones were born in Honolulu where some of my more recent ancestors were born.  I did trace many of my ancestors’ descendants who remained in Honolulu but none are those connect to these matches.

Here is a Maori match from MyHeritage.

Notice that the largest segment is 34.2cM.  The highest I’ve seen with a Maori.  How can a large segment last that long after many centuries?

And while the focus here is utilizing the largest segment to get a more accurately find a true 2nd to 3rd cousin match, we know how in one generation a large segment can quickly be reduced.

Comparing with the largest segment that my mother shares with her 1/2 3C.  This is how they connect.  I outlined in yellow all testees in this particular comparison.

The largest segment that my mother & her 1/2 3C share is 49.6cM (FTDNA indicated 52cM) according to GEDmatch.  But that particular segment was not inherited entirely by my mother’s sister and seemed to have been broken up thanks to recombination and turned into a 10.7cM and a 25.1cM segment.

My mother’s deceased brother seemed to have received that same segment or maybe even slightly larger.  And while he is not alive to test, his son did, and he shares 50.2cM with this 1/2 3C of our parents, or our 1/2 3C1R.

This is what the comparisons look like.

My younger brother got nearly the entire segment as my mother got it but I got a very small portion of it, just 14.3cM.  That’s a huge difference from 49cM.  Had my mother nor my younger brother got tested, I would not have been able to find this good match and would have concentrated on matches with large segments more than 20cM or even 30cM.  My older brother got DNA tested however he does not share any of this same matching segment.  In fact, he shares 0cM on this particular chromosome.

This 1/2 3C was key in finding my mother’s biological parents.  At the time I did not know how we were related but I did concentrate on this match because of the large segment size.

So how do we really filter all of these matches?  By solely concentrating on the largest segment?  You should definitely not spend too much time on large segments that are less than 20cM and whose shared total is way over 200cM.  With those particular matches, if you compare trees and notice no common geographic area, that would be a big indicator that it is a distant match.

Remember that with a 2nd cousin you would share a pair of great-grandparents.  With a 3rd cousin you would share a pair of 2x great-grandparents.  By that generation or even a generation further back or two if you find that you do not share the same geographic location, then the match is a distant match.  The same applies for large segments greater than 30cM.  If no common geographic location, then it is probably a distant match.

Confirming what could have been a NPE (non-paternal event) or misattributed parentage

Another useful tool for DNA testing is to answer those questionable paternity that either was brought up by a family member or documentation may not support what is known.  This was one of the main reasons why I got DNA tested in the first place.

Quite a bit of people getting DNA tested are finding what is known as an NPE (non-paternal event) or a misattributed parentage.  That is when the presumed or putative father was not the biological father.  This could have happened either recently, a generation ago, or way beyond that to where current living people may not be aware.

This is when people need to take the extra steps by testing other family members or also getting other specific tests, such as a Y-DNA test. Sometimes it can be a Y-DNA test that makes people realize that there was an NPE.

Back in July of 2015 I figured out who my mother’s biological mother was.  Her name was Rose Kanae, and Rose was married three times.  I found that one of her husbands — Joseph K. Akana  resided at the same address where my mother was born.  So the assumption was that he was probably my mother’s biological father.  The  Akana surname is of Chinese origin, and it is what initially made me believe that he was not the biological father.  My mother was told after having met Joseph Akana once as she was 5 years old, that he was a pure Hawaiian man.

Last October a cousin confirmed that Joseph indeed was my mother’s biological father.  It was explained to me by a couple of relatives that Joseph took the surname – Akana from his Aunt who married a Chinese man surnamed Akana.  Joseph’s original name was Joseph Kaapuiki, and later he went by Joseph Kaapuiki Akana.

This same cousin who confirmed that Joseph was my mother’s biological father did question Joseph’s paternity, suggesting that Joseph’s mother Elena Kauhi was not so faithful.  This is how I was able to confirm that Joseph’s father – John Kaapuiki was his biological father.

Below is my mother’s top 5 matches.

These all say “Possible range: 1st – 2nd cousins.”  Her first match is how I was able to figure out who her biological mother was.  This is how Frank is connected to my mother.

Frank and my mother are actually 1st cousins once removed, making Frank & I second cousins.  With females there is less ambiguity whereas with men there can always be that questionable paternity.

The second top match was “lkauhi” and this is how that person actually is related to my mother once I was able to get my grandfather’s genealogy.

“lkauhi” is off to the right, and she matches my grandfather Joseph Kaapuiki (Akana) via his mother’s side, through Elena Kauhi.  This would confirm that Joseph is the biological father of my mother since “lkauhi’s” grandfather Johnathan and Joseph’s mother Elena were brother and sister.

One of my cousins gave me the names of our grandfather Joseph Kaapuiki Akana’s ancestors going back as far as his grandparents.  His father John Kaapuiki‘s father was Kukahuna Kaapuiki.

Further research online revealed that the Akana-Kaapuiki family listed my ancestor Kukahuna and traced it a few more generations back.  But I was not confident at first to know that any of the names beyond Kukahuna were my own ancestors.  This is the same family that I was told my grandfather Joseph took his surname from, and that they were related.  Given that they listed Kaili Kaapuiki who married a Chinese man surnamed Akana as the sister to my ancestor Kukahuna Kaapuiki, I knew that was probably the connection but could not confirm it through documentation.

I looked for the genealogy of my mother’s 3rd match “milt17th.”  I contacted him and he confirmed his genealogy, that he was the grandson of Kaili Kaapuiki and Akana.

This confirms that John Kaapuiki was the biological father of my grandfather Joseph Kaapuiki Akana.