Someone asked in sci.bio.evolution, how evolution can produce species with a #
of chromsomes that differ from the parent species. I was wondering if
the # of chromosomes per species tends to change in parallel with speciation,
and what the relationship tends to be in general ( I assume each new
speciation doesn't automatically indicate a change in the # of chromosomes).
I know that if chromosomes are linked-gene clusters, then selection should
favor the producing of chromosomes containing genes that are adaptive in net,
but I'm wondering what would cause a new chromosome to form
(towards the end of becoming another net adaptive cluster of genes)?
Can the new creation be spontaneous (and under what conditions?), or does it
have to be derived from a pre-existing chromosome (by splitting)?
Thanks in advance for any info or leads.