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From: sbishop@desire.wright.edu
Newsgroups: sci.bio
Subject: Re: Man vs Woman vs Chimp DNA Percentages
Message-ID: <1254.26fa1e52@desire.wright.edu>
Date: 21 Sep 90 19:06:09 GMT
References: <999@massey.ac.nz> <6284@bgsuvax.UUCP>
Lines: 25

In article <6284@bgsuvax.UUCP>, gagen@bgsuvax.UUCP (kathleen gagen) writes:
> From article <999@massey.ac.nz>, by AChamove@massey.ac.nz (A.S. Chamove):
>> Over the past few years, there has been a lot of debate on the following
>> question: 
>> If chimps and humans are so close genetically, then why can we not make
>> hybrids?  Of course a lot of people say that we can and could.  Others
>> say that there are incompatibilites, but no one I have encountered has
>> been able to specify what those incompatibilites are. Can you?
> 
> The chimp and man have incompatable chromosome numbers.  Chimps (as well as
> gorillas) have 48 chromosomes in their diploid genome whereas men have 46
> chromosomes.  It is thought that human chromosome 2 (a metacentric chromosome
> having two chromosome arms) was formed through the fusion of two acrocentric
> (one armed) chromosomes.  The evidence for this is cytogenetic. It is based
> on banding patterns and the identification of specific genes to the same
> band on homologous arms of the human, chimp, and gorilla chromosomes.
> 
> References will be provided upon request.
> 
> Kathi  

I am fairly certain that horses and donkeys also have different chromosome
numbers so that is not a specific barrier to fertilization.  Of course, it's
been a while since I studied genetics so I could be wrong about the chromosome
count.