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Post by sarah on Feb 11, 2020 12:38:40 GMT -5
On 23andMe, my grandmother (approx age 85) has a second to third cousin match, however the match is my age (34)... so two generations apart. Does that mean the match's parents/grandparents will be much closer in genealogy to my grandmother or will it still be a second to third cousin match?
My family knows very little about my grandmother's biological family. All we have are anecdotal stories. We think she was separated from her parents around age 3 or 4. Her father was abusive so her mother fled to Hong Kong to find a family that would take her. We think she was born in Shantou Datou or maybe Dahao (汕頭達濠) in 1935. Her birthday and name were given to her in Hong Kong so all we have is limited information from DNA testing. Any suggestions are greatly appreciated.
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Post by merantau on Feb 12, 2020 3:51:57 GMT -5
To Sarah:-
The degree of relationship is based on amount of DNA matched. Assuming no half-relationships (i.e. descent via different wives, remarriage, etc), the same amount of genealogical distance should give the same expected value of match, where generational distance is the number of generations from subject up to common ancestor then down again to other person. Second to third cousin match would be equivalent to a range of 6-8 in generational distance.
You correctly surmise that the branches could be of different length. But the age difference is not particularly reliable in inferring this if there were large families and/or remarriage in the line of descent, I am the same age as some of my uncles and my granduncle! With Chinese incest rules, it is likely that only ONE of your match's parents (grandparents) will be a be 1 (2) step(s) closer in generational distance. Determining which will require you to do more testing, beginning with the match's parents and moving up the relevant line. The relevant grandparent COULD be equivalent to a first to second cousin match. However, there is always the possibility that an original apparent distant match arose by chance.
Have you considered using one of the Chinese genealogical DNA services? They are likely to have better sampling of the Chinese population. I can make no assurances of privacy with any of these services anywhere though.
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Post by sarah on Feb 29, 2020 12:22:20 GMT -5
Merantau, Thank you. That is very helpful information. I have not considered using one of the Chinese genealogical DNA services but I am open to it. Are they all in Chinese? Are there any you would suggest?
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