GENEALOGY-DNA-L ArchivesArchiver > GENEALOGY-DNA > 2001-02 > 0982594274
From: Helen <>
Subject: Re: [DNA] Dominant and recessive
Date: Mon, 19 Feb 2001 09:51:14 -0500
Back to the question of dominant and recessvie: is
it not true that dominant and recessive are not as
clear-cut as usually explained in General Biology
classes, and ordinarily, only biology majors
> In a message dated 2/18/2001 11:40:05 AM Pacific Standard Time,
> > I am a genealogy researcher with little or no real DNA training. I note that
> > the concept of Dominant and Recessive has disappeared from the dialogue of
> > the experts. Is it not viable?
> The terms dominant and recessive are still useful, but they apply to pairs of
> genes. If a trait is dominant, one copy is sufficient for expression; if it's
> recessive, both copies must be present.
> I suspect the reason that we don't discuss these concepts here is that the
> tests of genealogical interest use mtDNA and Y chromosome markers. They are
> not testing for genes per se -- they are looking at parts of DNA which not
> expressed, the so-called "junk" DNA. Also, the mtDNA and Y chromosome markers
> don't come in pairs -- you have one variety of mtDNA, inherited from your
> mother, and if you are male, one Y chromosome, inherited from your father. In
> a sense, mtDNA and Y chromosomes automatically dominant.
> We did have a short thread on whether it would be practical to have a
> database of genetic traits which seem to be handed down over many
> generations. If you want to search the archives, I think the keyword "quirks"
> would bring up the messages. I'm still pondering if this is feasible -- I can
> see lots of problems in defining traits, for example.
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