GENEALOGY-DNA-L ArchivesArchiver > GENEALOGY-DNA > 2010-03 > 1269934290
From: Angela Cone <>
Subject: Re: [DNA] Family Finder Test
Date: Tue, 30 Mar 2010 20:37:08 +1300
Hello Kathy, (& Stephen, John, Richard..)
Yes,.. this does make sense,. this is something that I am interested in as
Both sibling comparisons and grandchild/grandparent comparisons would give
us useful information (with the latter being clearer in indicating the
actual crossover events).
I'd imagine that there will be far more tested sibling comparisons compared
to tested grandparent/grandchild comparisons.
I'm interested in collecting data on both of these, and as a part of this am
creating comparison diagram galleries.
These can be seen here:
(the latter is still under construction,.. - the text labelling needs to be
So far the only diagrams included are that of the 23andme mendel family, but
I would like to expand it much further in the future. To do this, I need
everyones help..... (or more precisely, everyone who has been tested and
also has a sibling or a grandparent/grandchild tested - with either 23andMe
or FTDNA's "family finder")
I was planning to announce this after writing a page on how people can
submit diagrams to me to be included in the diagram and what data I'd like
to collect. I haven't got this page ready yet as I'm currently battling a
head cold (plus making sure that "captain chaos" doesn't get up to too much
I'll probably make a bigger announcement about this in 4-6 weeks time
("Captain Chaos" and I are shifting in a months time, and after the shift I
will have more time to do DNA related things).
On Tue, Mar 30, 2010 at 7:32 PM, <> wrote:
> > It should be possible to gather crossover statistics
> > as more families partake in the FF tests
> I have a Google Doc spreadsheet started to look at the 23andMe RF
> transitions at
> When comparing two siblings, you actually are taking into account four
> chromosomes, each is a combination of two grandparents in terms of
> If you assume that there will not be exactly the same crossover
> location, you can take the crossover points and divide by 4. So if
> there are 7 crossover
> points within a chromosome in the graphic in the Family Inheritance
> section, then you would divide by 4 and come up with an average of 1.75
> crossovers for that chromosome for that particular sibling pair. There
> are likely to be more crossovers than our estimates because some of the
> chromosomes have missing information. I am also counting the faintest
> blocks that are barely visible for my family, so there probably will be
> observer error involved as well.
> Does this make sense?