Furthermore, though the islands have a rich variety of flowering plants, insects, birds, land snails, and fish, they have no native species of reptiles, amphibians, or conifers, and a single species of bat and a seal species are their only living native mammals. Why do some kinds of organisms live in Hawaii but not others?
Finally, some categories of native Hawaiian plants and animals are represented with remarkable abundance. For example, approximately 800 species of flies belonging to the genera Drosophila and Scaptomyza exist in the Hawaiian islands—about a quarter of the worldwide total and far more than are found in a comparable area anywhere else on earth. But only about 15 percent of the world’s total of insect families is represented in Hawaii. Before the arrival of humans, Hawaii had no native species of termites, ants, or mosquitoes, according to the fossil record.How can all these facts be explained?