Re: Change from 48 to 46 chromosomes

ron house (house@helios.usq.EDU.AU)
Tue, 24 Oct 1995 02:25:33 GMT

djb209@leonard.anu.edu.au (David J Betty) writes:

>48 chromosomes appear to be an ancestral state for great apes. Sometime in
>the human line of descent between the last common ancestor of humans and
>(presumably) chimps, two pairs of acrocentric chromosomes evidently fused
>to become a pair of large metacentric chromosomes. This pair are the
>second largest in humans, and examples are labelled chromosome 2. (Human
>chromosomes are labelled in approximate descending order of size.) The two
>halves of human chromosome 2 (2p and 2q) each have separate chromosomes as
>homologues in the karyotypes of chimps.

Can anyone explain how this works? I mean, if a single individual has
a mutation leaving him with a different no. of chromosomes, surely he
would not be able to breed with anyone else? Wouldn't it be impossible for
the single chromosome to match up with two separate ones?

--

Ron House. USQ | A nonviolent diet is the
(house@usq.edu.au) Toowoomba, Australia. | foundation for a nonviolent world.