> It's called "The why behind the Y chromosome" (G. Vogel,
> _Science_, 286, 877-78) and reports on a research report on p.
> 964 (which I didn't keep probably because I couldn't understand
> it). It reports research suggesting that the Y chromosome may
> once have been as large as the X, but progressively shrank. The
> article gives a neat diagram of the X, showing the hypothesis
> that the Y diverged in four stages, and that only a tiny part of
> the short arm can still recombine with the X.
>
> Go get it, Joyce!
>
> -Stephen
> ------------------------------------------------------------------------
> Stephen Black, Ph.D. tel: (819) 822-9600 ext 2470
For the last 250 million years chromosomes have had a habit of doubling and
increasing in length in alot of species. For example, dogs, cats, and foxes are
related 10 million years ago. Today the cat has 38 chromosomes and the dog has
78 chromosomes. We use to have 48 chromosomes but two fused together making
chromosome one. This cut us back to 46.
The reduction in y could be due to genomic imprinting. The chromosome know who
it came from the male or female. Different chromosomes are turned on dependent
upon which sex it came from.
Ron Blue
