They are reassemble new each generation. Recombination reduces phenotypic variation by producing more phenotypes that are near the mean, and reducing the frequency of the extreme phenotypes. Not common, because having four homologous chromosomes causes unequal separation at meiosis. There are some polyploid complexes, with repeated hybridizations. A loop must form when the chromosomes are lining up in meiosis Fertility may be reduced because many gametes are inviable.
Recombination is suppressed.
Natural selection often eliminates one of the arrangements, so polymorphism for inversions within a population is uncommon. This can be a mechanism of reproductive isolation of closely related species. Duplications and deletions Unequal crossing over can change the amount of DNA in the offspring. Deletions are usually inviable, but duplications may be advantageous. Duplications can result in gene families, because each copy can evolve on its own.