Ec 4 Essay Example | Topics and Well Written Essays - 500 words

Ec 4 - Essay Example These two definitions are summarized as historical genesis and current utility. This presents a dilemma of incorporating distinct criteria of current utility and historical genesis under a single phrase. Biologists have failed to to acknowledge the confusion between these two distinct definitions for they tend to observe natural selection as a dominant evolutionary progression, making the historical process and the current utility seem as combined (Gould & Vrba 7). An outstanding instance of how linking these two definitions has caused misunderstanding is Darwins’ and Williams’ failure to label the infused sutures as adaptation since they were not built by selection to function as they do in mammals (Gould & Vrba 7). Williams calls this feature as an accidental effect that aids in the survival of mammals and not an adaptation. Nonetheless, these biologists failed to give the features that develop as a result of fitness to a current role a name (Gould & Vrba 7-9). Since the new features that develop in organisms to aid in the survival of the descen dants re not considered as an adaptation, they develop due to capability and not natural selection and are referred as exaptation. This, then, generates a variance between those features that develop due to natural selection and fitness to a current role. In this case, the mammalian sutures are an exaptation and not adaptation (Gould & Vrba 7-10). Exaptation offers a solution to the dilemma of preadaptation. Evolutionists and biologists have experienced trouble with the concept of preadaptation. Most of them have connected the features that develop to assist in performing a new role as preadaptation. If adaptation were developed for a current use, then structures functioning in a distinct and subsequent way cannot be preadaptations. In this case, preadaptation has been associated with indeterminate teology. Teology implies a description of the role of a given