Re: DNA Matches - Most CentiMorgans or Largest Segment? #poland #dna #galicia #ukraine #education


The largest segment data at Ancestry is new and a helpful piece of the puzzle, but we need to also look at what is left over. 

For example, 200 cM , 25 largest segment, and a total of 8 segments would mean that there are 175 cM to spread over the remaining 7 segments, or they are all 25cM, this is likely a pretty close match (and a statistical improbability, but I am trying to keep the math simple here.) The larger segment average points toward the shared DNA being from a recent close relationship.

 On the other hand 200 cM, 25 largest segment, and a total of 15 segments means 175cM spread over 14, and we have about 12.5cM on average.  The smaller average segment size points to a more likely case of many distant connections (endogamy) vs a recent close connection.  It is, assuredly, playing the statistics, but it can help us  decide which matches are more likely to turn up something we can pin down.  Because it is playing the odds, though, sometimes it will be wrong. 

Vivs Laliberte

Orange County, Calfiornia

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