The Extended Phenotype

Abstract

Introduction: The extended phenotype is a particular way of approaching the biological and evolutionary concept of the phenotype. The genotypic manifestation (phenotype) will be viewed beyond the limits of an individual`s body. Extending past the organism to the other phenotype could be seen as a unique way of adjusting to the conditions of the environment. Parasites that manage to extend their phenotype, thus changing the phenotype of their hosts deliver a marvelous representation of the extended phenotype and the idea that a gene has many different effects on its environment, inside or outside the body. Materials and Methods: Using the book ‘The Extended Phenotype` and several research papers three examples will be presented. Results: The first example is the Dicrocoelium dendriticum (fluke) and its life cycle. Following several studies of the biology of Dicrocoelium dendriticum , the utterly complex way this microorganism passes through will be presented. The way it manipulates two completely different types of organisms, namely the Cochlicopa lubrica and Formica fusca will be explained in further detail. The ‘fluke`, deliberately turning the black colored ant into a parasite-driven organism, ensures a further infestation of its final host - either a sheep or a human, causing serious liver damage. The second example is the Spinochordodes tellinii . This organism infects grasshoppers and upon reaching its adult form, brainwashes its host through mimicking neurotransmitters and endocrine proteins, making the grasshopper seek out and plunge into water. The third example is the malaria parasite and especially the way it makes infected female mosquitoes that carry the parasite significantly more attracted to human breath and odors than uninfected mosquitoes. Conclusions: It can be concluded that that the extended phenotype is not only an idea but a steady phenomenon among different organisms.