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From: pell@boulder.Colorado.EDU (Anthony Pelletier)
Newsgroups: sci.research,sci.med,talk.rumors,misc.headlines
Subject: Re: Life imitates art?
Message-ID: <1157@sigi.Colorado.EDU>
Date: Mon, 25-May-87 17:36:28 EDT
Article-I.D.: sigi.1157
Posted: Mon May 25 17:36:28 1987
Date-Received: Tue, 26-May-87 03:29:17 EDT
References: <6693@allegra.UUCP> <1664@tekcrl.TEK.COM> <1084@aecom.YU.EDU>
Sender: news@sigi.Colorado.EDU
Reply-To: pell@boulder.Colorado.EDU (Anthony Pelletier)
Organization: University of Colorado, Boulder
Lines: 49
Xref: mnetor sci.research:107 sci.med:2207 talk.rumors:827 misc.headlines:555

>In article <1664@tekcrl.TEK.COM>, terryl@tekcrl.TEK.COM writes:
>> In article <6693@allegra.UUCP> atd@allegra.UUCP (Anton Dahbura) writes:
>> >
>> >      ITALIAN SCIENTISTS CONFIRM APEMAN CAN BE CREATED
>> >
>> >      by Uli Schmetzer (Chicago Tribune, May 14, 1987)
>
(Craig Werner) writes:

>	This ignores the fact that Apes have 48 chromosomes and
>humans have 46, and sounds more like somebody's idea of a hoax,
>or a typical article from the National Enquirer.
>-- 
>			      Craig Werner (MD/PhD '91)
Craig, if you mean second year student, say second year student.

Once again you show your passion for facts without any real understanding
of what they mean.  I do not for a moment suggest that the article about
the chimp/human hybrid is necessarily true.
I do, however, wish to point out that
you reason for declaring it false is irrelevent.  No doubt, someone has
already pointed out to you that hybrids between two species with
differing numbers of chromosomes do exist (have you heard of mules).
In horses 2n (=2x)= 64; in donkeys, 2n=62.  This has no bearing
what-so-ever on the fitness of the hybrid offspring.  In fact, due to
heterosis, the hybrid is superior in many ways to either parent
(don't ever tell my horse I said that :+).
The important fact in survival of the hybrid is not chromosome number,
but appropriate dosage of gene-products.
Since estimates are that humans and chimps are more closely related
at the gene-homology level than horses are to donkeys, a
chimp/human hybrid might very well be viable.

The fact that the animal is aneuploid does have a rather dramatic
on meiosis.  The chromosomes do not have homologues with which they can
pair at meiosis 1.  In the mule, pairing between the analogous chomosomes
of each set does occur, albeit poorly.  Depending on the segregation
of the extra donkey chromosome as well as other factors, sometimes
a viable gamete is produced (very rare, but it does happen).

The rather cute trick that plants such as triticum aestivum (wheat)
have used to produce fertile new species from a sterile hybrid is to
undergo endo-reduplication to produce a 2n (6x, in the case of wheat)
plant.  I am told that, in mammals, polyploids are always aborted.
So a similar approach, using colchicine to disrupt the mitotic
spindle in the zygote, would probably not work on the putative
chimp/human cross (imagine a 2n=94 fertile new primate species).

A.J.P. (a few ultimately irrelevent "higher" degrees)