Chromosome Number Alteration

[muffin10]

Organisms have different chromosome numbers. I'm wondering how this can evolved. If an organism has something that occurs to change its chromosome number (splitting, agglomeration, whatever) how could it make fertile offspring when mating with another member of its (ex) species?

[vascop]

Read this http://scienceblogs.com/pharyngula/2008/04/21/basics-how-can-chromosome-numb/

[muffin10]

Thanks vascop - precisley what I was looking for! I think that he's a bit optimistic about the success of pairing in meiosis, and also the spread of the variation through the population, but I suppose that it only takes a few...

Interesting point about it being a mechanism for sympatric speciation - always a difficult concept to explain.