Question 1
Describe the differences between divergent evolution, convergent evolution and parallel evolution and provide an example for each type of evolution.
Divergent evolution occurs when change from a common ancestral species increases as time passes, leading to a speciation event; that is, the evolution of two new species. Convergent evolution on the other hand differs from divergent evolution because it is the development of similar features separately in unrelated groups of organisms though natural selection. Finally Parallel evolution is a look at species that are more closely related then those of divergent evolution. It is the independent evolution of structures with similar form and function in two closely related organisms. …show more content…
An example of homologous characters is the four limbs of tetrapods. Birds, bats, mice, and crocodiles all have four limbs. Sharks and bony fish do not. The ancestor of tetrapods evolved four limbs, and its descendants have inherited that feature. Comparative embryology is the theory that all vertebrate embryos follow a common developmental path due to their common ancestry. All have a set of very similar genes that define their basic body plan. As they grow, the differences that will distinguish the embryos as adults become more and more apparent. The study of this development can yield insights into the process of evolution. While these features have a function vestigial structures do not have a purpose organisms have structures or organs that seem to serve no useful function. For example, humans have a tailbone at the end of the spine that is of no apparent use. Some cave-dwelling salamanders have eyes even though members of the species are completely blind. Vestigial organs are often useful in other species. Vestigial structures can be viewed as evidence for evolution because organisms having vestigial structures probably share a common ancestry with organisms in with organisms in which the homologous structure is