GENEALOGY-DNA-L ArchivesArchiver > GENEALOGY-DNA > 2008-11 > 1225902440
From: Al Aburto <>
Subject: Re: [DNA] 23andMe Results (attention Chia)
Date: Wed, 05 Nov 2008 08:27:20 -0800
Ah! Thank you for pulling me back into the right frame of reference!
> In a message dated 11/4/2008 6:33:03 AM Pacific Standard Time,
>> What I would like to see is percentages for the upper and lower halves
>> and both too for the Ancestry Painting. That would be helpful although
>> I'm not sure one really knows if the upper half is paternal or maternal?
> No, there's no way to tell which is which. Indeed, I'm not even sure they can
> phase* a whole chromosome so that everything in one half (top or bottom)
> actually belongs to one chromosome. Your genotype results are always given in
> alphabetical order, so the first one listed could come from your father for one
> SNP and from your mother in another SNP. The combinatorial possibilities grow
> very rapidly. Anders has been working with a program called PHASE that uses
> population data for comparisons -- maybe he can shed some light on this.
> Phasing: Determining the haplotype phase (the arrangement of alleles at two
> loci on homologous chromosomes) from genotype data using statistical methods.
> Ann Turner