> Autopolyploids possess at least three homologous chromosome sets, which can lead to high rates of multivalent pairing during meiosis (particularly in recently formed autopolyploids, also known as neopolyploids) and an associated decrease in fertility due to the production of aneuploid gametes.
Granted, there's an implication that meiosis won't split a cell into one monoploid gamete and one diploid gamete, but is more likely to divide chromosomes between gametes on a chromosome-by-chromosome basis. The implication is that the triploid organism would most likely evolve into a tetraploid organism, as described in the rest of the same paragraph:
> Natural or artificial selection for fertility can quickly stabilize meiosis in autopolyploids by restoring bivalent pairing during meiosis. Rapid adaptive evolution of the meiotic machinery, resulting in reduced levels of multivalents (and therefore stable autopolyploid meiosis) has been documented in Arabidopsis arenosa and Arabidopsis lyrata
I'm not sure what your argument is. Your quote includes the phrase "decrease in fertility."
So let's say an organism has four (A, B, C, D) chromosomes and is triploid.
Split the following cell into two daughter cells: A1 A2 A3 B1 B2 B3 C1 C2 C3 D1 D2 D3.
Besides the fact that I don't know what a cell does when it has to try to "pair" three sister chromatids, what happens when the resulting gametes are made and then attempt to fertilize each other? You will end up with 2, 3, or 4 copies of each chromosome. This is a problem not only because how does that organism do meiosis, but also, the expression levels of the genes on the various chromosomes are going to be unbalanced.
