Free «Origin of Animal Body Plans» Essay Sample

The existence of life in different forms in the past is evident from the fossils found in different areas, but scientists seem to make gross assumptions that raise some doubt about their facts. For instance, Erwin et al. reveal that some of the fossils found do not show any direct link to the modern creatures. This assumes that modern creatures evolved from the ancient one null. In addition, scientists assume that some marks in the form of burrows and trails were made a long time ago by creatures believed to have lived in those days. However, it difficult to accept this assumption given that even creature living in this time and age can make similar marks irrespective of their morphological characteristics. This puts some doubt on the credibility of some scientific and raises the question of whether evolution is based on such gross assumptions. This is evident once more in the sense that science does not provide an explicit explanation on the so-called abrupt transition of creature from simple to complex life forms.

The relationship between different phyla has also become difficult to establish using comparative anatomy. Although scientists agree that there comparative anatomy has failed to establish the relationship between living organisms and different fossils found in different parts of the world, a new approach has been discovered (Erwin et al). Molecular biology is taking the lead in investigating the link between fossils and modern creatures. DNA studies have shown that organisms with more similarities belong to one species. This means that animals that share more genetic characteristics are closer in terms of morphology and other intrinsic biological characteristics. However, there are some issues that molecular procedures such as DNA tests have not answered. In the case of apes and human beings, common knowledge has it that there are many similarities in DNA sequence. If these discoveries indicate that man and apes have a common origin, what process isolated human beings and apes given that human beings are said to evolve from apes? Why is it that human being are said to have come from apes and not vice versa? These are some of the questions that molecular studies fail to answer when associating different animal species with common origins.

The Neoproterozoic body indicates that multi cellular organisms originated single celled organisms. However, this belief does not explain why some organisms remained singe celled while other became multicellular. The only conditions that could have led to his occurrence are probably environmental conditions, which the Neoproterozoic body plans originated (Erwin et al). Despite the fact that all organisms start from singe cells after fertilization, the concept of as mentioned in evolution theories does not fit here. This is because long periods are associated with morphological changes that cannot occur during gestation alone.

Early body plans have many unresolved issues given that science cannot resolve some issues. Animals are believed to have left traces on the sea floor cannot have their genetic properties verified given that their genes are not available. Fossil records have established the presence of at least six Hox genes that are believed to have evolved over a period of approximately 35 million years (Erwin et al). Hox genes are presented in three different scenarios, which do not qualify as satisfactory explanations on how body plans were formed. This means that the manner in which body plans were formed remains mysterious given that even science has failed to provide clear explanations.


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