Autosomal - who is related?

I recently received an email that got me wondering if you might not understand the relationships that testing for Autosomal chromosomes can develop for you and how to understand them.

In this graft you see that your Great grandparents are a solid color - right? in reality the are mixed colors too, but solid is needed for the explanation. As you see, the colors mix as they get closer to you; that is basically what happens to your Autosomal chromosomes as the combine and recombine at each generation. Of course this is only a graft of ONE chromosome, you have 22 pairs that do this recombination dance. Now your chromosomes are pairs to make up the pair, you get one of the set from Dad and one from Mom, They don't recombine with each other they do the dance with themselves. So you have a clear line from Dad and a clear line from Mom, but with out some work you don't know which parent gave you what set.

The email asked " On my actual Family Finder DNA test results I have 4 matches on Chromosome
> 7, called A, B, C, and D.
>
> A is from 82.2m to 94.9m - 10.08cM and 3100 SNP.
>
> B is from 86.1m to 96.3m - 10.45cM and 2700 SNP.
>
> C is from 90.7m to 102.7m - 9.24cM and 2800 SNP.
>
> D is from 97.1m to 106.2m - 9.98cM and 2200 SNP.
>
> Does this mean A, B, and C are all related to each other and to me? And D
> is related to C (and me) but D is not related to A and B?
>
> Is it correct that while the results do not indicate that D is related to A
> and B, it does not rule out the possibility that D could be related to
> either A or B or both?

My response was:

No it means they are all related to you.
First you need to understand that all chromosomes are PAIRS one chromosome from Dad One chromosome from Mom.they are numbered the same so unless you do some detective work you will not know which parent your cousins descend from.

Now if you had known cousins or half siblings from either parent tested and they matched you on specific sets of segment numbers then, if one or more of these unknown cousins matched them then you would know up what one of your  parents line they descend from.

but see if they match each other then if the three of you figure out what parent's line converges. you will know what parent the match comes from.

Just incase you do not know this...a negitive match DOES NOT MEAN your not related, it just means a measurable segment did not survive the combination recombination to either of the two persons comparing.

Read down the page it helps explain the different types of testing....

A good explanation is here:     http://www.geneticsand.us/

Hope this helps : Nelda