Autopolyploidy

Autopolyploidy causes the offspring to be reproductively isolated from its parent species. After the formation of the tetraploid offspring the gametes that they would form would be 2n of 6 chromosomes. The parent species forms gametes with n of 3 chromosomes. The parent species and offspring species can produce an offspring with 3n, although they would be sterile because gametes would not be able to form since a chromosome would be left unmatched during meiosis. This is an example of post-zygotic reproductive isolation because the offspring would be sterile but would have been viable.