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I say that chromosomal rearrangements in and of themselves are in fact NOT the impetus for evolution.
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And I would agree, that they are not in and of themselves the impetus for evolution (gene duplication is also important, and there have to be small mutations, at the single nucleotide, or small indels, or epigenetic factors level as well). But, gene flow in rearranged chromosomes can be suppressed, allowing divergent evolution in the two types of chromosome (original and rearranged), possibly triggering and at least providing the process for parapatric speciation. And there is evidence that incompatible beneficial mutatations concentrate on the rearranged chromosmes during the period of hybridisation after rearrangement.
See Navarro and Barton, Chromosmal speciation and molecular divergenece - accelerated evolution in rearranged chromosomes, Science 300, 321 -325.
This a study of protein evolution in man and chimpanzee, focusing on the difference between rearranged and co-linear chromosomes in these species, that I have summarised and reviewed here:
Human/chimpanzee divergence
[This message has been edited by Speckle, 05-05-2003]
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