Evolutionary Theory Case Study Example | Topics and Well Written Essays - 500 words

Evolutionary Theory - Case Study Example Numerous species have not been named and as such lumping of organisms together as belonging to the genus and species classes may be incorrect as the case in the repopulation program in the Islands of St. Kitts and the neighboring Island of Nevis. These two species of rodents appear to be identical in morphological features and that is the reason why they were taken to be of the same species. However, their morphological similarities have nothing to do their genetic makeups since the DNA (Deoxy-Ribonucleic acid) are quite distinct from each other. The differences in DNA can be explained through concepts of evolutionary theories of natural selection of stabilizing selection and diversifying selection    This is a type of natural selection that experiences genetic diversity decrease in a population that that is stabilizing. It has been argued that this is the most common way through which natural selection takes place. As such, the stabilization process employs negative selection which results in organisms with intermediate phenotypes being selected. In the case of the two islands, it is quite clear that the rodents from the St. Kitts Island underwent a stabilizing selection because their traits seem to be normal or not very much different from those of the rodents from the other island of Nevis. Probably, the two islands were connected and after a natural disaster like an earthquake, they became separated. It follows that those rodents that had intermediate phenotypes were selected over those that had extreme phenotypes hence the development of the new distinct species. Diversifying selection is used to refer to the exact opposite of stabilizing selection whereby the extreme phenotypes in organisms are naturally selected over the intermediate phenotypes. This can be explained by the studies done by Charles Darwin in the Galapagos Island with regards to the finch populations.