The incidence of polyploidy Allopolyploidy is much more common than autopolyploidy. The fern genus Ophioglossum has 2n ranges from about 240 to 1260 Origin of species by hybridization Species with the same chromosome number can sometimes arise from hybridization. Much more common in plants than animals. Rates of reproductive isolation are variable, but an average is about 3 million years for reproductive isolation. Many topographic and other barriers.
Speciation is at the boundary between microevolution and macroevolution.