For example, into Apini tribe from honey bees we have 9 species but among them, Apis mellifera has the most of the subspecies but dwarf honey bees have not any subspecies. Or in the Euglossini tribe, the genus Euglussa has the most species higher than 120 and other genus in this tribe have low species. What is the main reason for this difference? Whether a genus or species with highest numbers of species/subspecies has a specific genomic structure?
Hello Taghi;
1.When populations of a species are small and or isolated from one another they are likely to diverge from one another.
2. When a widespread species occurs in a mosaic of habitats or in a mosaic of competitors/predators/resources there is likely to be differentiation of the species.
Factors like these are generally invoked to explain population differentiation.
3. For parasitic species, host selection mechanisms may cause isolation of parts of a population in the sense that the site of mating may cause isolation. The fly genus Regoletis, the cerambycid genus Megacylene are examples of suites of species that are isolated only by host plant selection.
4. There are many other examples of similar mechanisms that cause reproductive isolation.
Examples like these will stimulate thinking about many other factors that increase the likelihood that a breeding population will be fragmented.
Best regards, Jim des Lauriers
