This sort of discussions always bring to mind that what one is trying to do
is to find a metric in the DNA space. Just like we do when we define
distance in ordinary space. I do not think such a metric has been found.
----- Original Message -----
Sent: Wednesday, October 10, 2001 9:40 AM
Subject: Re: the definitions of evolution
> Tim Ikeda wrote in one part of his post:
> > Well, let's take the chimp/human split as an example. Do we have a
> > process? Yes. First, we have sex. We have empirical evidence that
> > do not reproduce exactly. We have evidence that relatively few changes
> > the development pathways of organisms may have large effects of
> > -- Changes that even retain or enhance viability. We have evidence that
> > chimp and human genomes exhibit _tiny_ differences, no greater than what
> > has even been seen among organisms of the same species. We have observed
> > numerous modes of speciation in the wild and a few in the lab. We have
> > observed and even understand the biochemical basis of the generation of
> > genomic variation. Basically, we have ample evidence that populations
> > diverge genetically over time and frequently speciate. We may not
> > know what drives or supports divergence, but it is an observed reality.
> > Determining whether a process occurred is simple, knowing the exact
> > the mechanism/s involved at any particular time is the problem.
> One thing that does puzzle me is how the chromosomes of
> related species can be so different in there arrangement
> in the respective genomes. For example, morphologically,
> the mouse and the rat look quite similar. Yet the
> arrangement of the genes on the respective organisms seems
> very different. Likewise, often the introns also seem to
> have almost no homology.
> I don't say this to argue, but unlike Li's lucid
> description of the globin gene, I find the speciation
> process quite baffling. In my ignorance at least, I
> would have expected it to be rather similar.
> by Grace we do proceed,
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