Evolutionary movement of centromeres in horse, donkey, and zebra:

Centromere repositioning (CR) is a recently discovered biological phenomenon consisting of the emergence of a new centromere along a chromosome and the inactivation of the old one...Even more surprisingly, five cases of CR have occurred in the donkey after its divergence from zebra, that is, in a very short evolutionary time (approximately 1 million years).These findings suggest that in some species the CR phenomenon could have played an important role in karyotype shaping, with potential consequences on population dynamics and speciation.

I though this was interesting because a) I don't know much about higher order genetic changes (chromosomal rearrangements, etc.) b) we've talked about chromosome # differences between wild and domestic horses before (they are full interfertile). Anyway, I know aneuploidy is usually the problem, but I think there will be some really interesting stuff coming out of this area (I wonder if RPM could offer more?).