Re: RC: Re: Re: Amblin/Racking/what ever

["Truman Prevatt, Ph.D." <truman.prevatt@netsrq.com>]

CMKSAGEHIL@aol.com wrote:

> In a message dated 6/22/00 11:45:50 AM Pacific Daylight Time,
> truman.prevatt@netsrq.com writes:
>
> << The passing of genetic information is a discrete process not  a
> continuum.>>
>
> Yes and no.  It is a continuum in the sense that all of the genetic material
> other than a few mutations goes back in an unbroken line through thousands of
> years of ancestors.
>
> << That is a half Arab has half it's genes from an Arab. If he is bred to a
> non
>  Arab then the Arab contribution is 1/4. Ten generations later with breeding
> to
>  nonArabs, the Arab content is 1 in 1024 and twenty generations it would be 1
> in
>  over a million. >>
>
> Nothing wrong with your math, Truman--only your premises.  What you are
> saying is exactly why practical folks don't get hung up on "purity" when
> maybe there was one stray ancestor "back there" 15 generations.  However, the
> sort of influence we're talking about in founding breeds is not a single
> ancestor, but rather a major percentage of the ancestry.  Example--Justin
> Morgan's pedigree is roughly half Arabian--give or take a little.  This is
> not the case of a single outcross to Arabs, but rather the breeding together
> of MANY horses who have a significant amount of Arabian blood over a period
> of time, so the percentage is not dropping.  If you breed half-Arabs to each
> other repeatedly, you will get a bell-shaped curve of how many actual genes
> are there from the Arabian ancestors--a very few will have primarily Arab
> genes at one extreme, and a very few will have not very many at the other
> extreme, but the bulk of the offspring will have something in the middle--in
> other words, something approximating half of their genes coming from Arabs.
>

That's exactly the type of selection, i.e. among random horses be they with some
Arabian, that will wash out pretty quickly. There are about 100,000 different
genes identified in the human gnome project. I would assume that the horse
carries about the same number. So given not breeding back pure Arabians into
morgans, then it would not take long before the Arabian influence would be
washed out.

I also remember that there (at least was) is not acceptance as to the actual
sire and dam of Justin Morgan's horse.  So if this is the case then that even
makes the whole situation fuzzier. Some of you Morgan fanciers out there want to
comment on that.

Truman

--
Truman Prevatt
Brooksville, FL

Mystic "The Horse from Hell" Storm
Buck's Mystic Karma
Rocket a.k.a. Mr. Misty
Jordy a.k.a. Bridger (when he is good)
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