[js1138]

If you plant the seeds produced from hybrids, your results will not be good.

I don't doubt that, in most cases. But at some point in evolution there must be discontinuities in chromosome count. If these are always absolute barriers to reproduction, there is a problem.

[shubi]

"If these are always absolute barriers to reproduction, there is a problem."

Let's say you had an insect whose chromosomes got "stuck". It produced 1000 eggs. All of a sudden you would have a new species with a thousand individuals.

[jennyp]

I don't doubt that, in most cases. But at some point in evolution there must be discontinuities in chromosome count. If these are always absolute barriers to reproduction, there is a problem.

IIRC, there's a variety of chromosome counts among horses.