question_answer 62)

  Does the occurrence of diversity of animals on earth suggest their diverse ancestry also? Discuss this point in the light of evolution.

Answer:

                  Since animals show a vast diversity in their structures, they probably have diverse ancestry. Because common ancestry may greatly limit the extent of diversity, e.g., all birds are closely related, they have common ancestors but birds and reptiles are also related. We can thus build up small groups of species with recent common ancestors, then super-groups of these groups with more distant common ancestors, and so on. In theory, we can keep going backwards like this until we come to the notion of a single species at the very beginning of evolutionary time. As many of these diverse animals are inhabiting the same habitat, their evolution by geographical isolation and speciation is also not likely to occur. Thus, occurrence of diversity of animals on earth suggest their diverse ancestry also.