25 August 2019

YouTube: Endogamy Explained

At Saturday's Ottawa DNA group meeting, after an explanation of what endogamy is, the custom of marrying only within the limits of a local community, clan, or tribe, a survey found that more than half those in attendance had an endogamous line in their ancestry. As it wasn't well understood I mentioned a new YouTube video which explains how to overcome endogamy and locate the significant matches.

Jewish is mentioned in the title but endogamy is relevant more broadly.

The presenter Jarrett Ross, the GeneaVlogger, has a YouTube channel with lots of other videos free to view.


Lynne Willoughby said...

I thought I knew what Endogamy was but now am not so sure. I will definitely watch this video. In a discussion I had last night with another genealogist I think i might have been confusing "co-mingling" with endogamy. I put my hand up but am not not certain I shoud have. 😀

Anonymous said...

Yes true Endogamy by scientific definition is multiple marriages within a known related group going far back into time. Think of Island populations or an isolated area such as parts of the French or Swiss Alps, where there are villages with only 4 surnames. When working with DNA, Endogamy in your pedigree is important to know about. What I have mentioned in the past is Pedigree Collapse - somewhere back with your multiple great grandparents you have the same couple appearing. Having the same couple appearing twice in your tree, increases the possibility of inherence of DNA from that couple coming forward. Or another way of thinking of this in view of DNA Cousins, Pedigree Collapse creates a situation where you may have a higher than normal opportunity to have DNA matches to that couple since you may carry more than expected Segments. As for Co Mingling, that is what I discussed with Maurice Gleeson, re Irish families marriages within known family groups over time , but more recently as in less than 250 years, which makes it within the time frame of DNA 5th to 8 th cousins. This Co mingling as I call it is more reflective in the Shared Cousins Lists or Shared Match lists. Co mingling of my known Paternal and or Maternal groups creates for me a list which often showing a mix or blend of DNA cousins that are related to me directly via a ancestor in both our pedigree trees and by a collateral line of one or both of our related families. That is why pedigree trees should be back as far as possible at least to the 2nd or 3rd great grandparents, to see if there is one or more possible family lines that could have provided the shared DNA segment(s). The issue then is to decide if a segment of less than 30 cm is a true segment - inherited by decent (IBD) or a non true segment which is a false positive (IBS).

Shirley M said...

John - I thought that I had left my name with the Posting I added at 14.00, as Anonymous, not sure what I did to show it that way, my first comment posting. I watched the first part of the Video, will watch all of it later tonight, thank you for sharing the link. Shirley Monkhouse.