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ISSUES OF ORIGINS IN ZOOLOGY AND GENETICS

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ISSUES OF ORIGINS IN ZOOLOGY AND GENETICS:A LOOK AT THE EVIDENCEMarcia Oliveira de PaulaIssues in ZoologyProblems in the animal fossil recordProblems on origin of complex structures in animalsIssues in GeneticsDNA ReplicationStructure of eucaryotic chromosomesGene expressionTranscriptionTranslationRegulation of gene expressionMutationConclusionBibliography271Institute for Christian Teaching Education Department of Seventh-day Adventists ISSUES OF ORIGINS IN ZOOLOGY AND GENETICS: A LOOK AT THE EVIDENCE By Marcia Oliveira de Paula Centro Universitário Adventista de São Paulo São Paulo, Brazil 431-00 Institute for Christian Teaching 12501 Old Columbia Pike Silver Spring, MD 20904 USA Prepared for the 26th International Faith and Learning Seminar held at the Geoscience Research Institute, Loma Linda, California, U.S.A. July 16-28, 2000272Introduction Zoology and genetics are required courses for biology majors, and genetics is required in the programs of several courses in health areas, such as Medicine, Nursing, Dentistry, Psychology and others. Both subjects are usually structured around the theme of the theory of evolution. Also, the majority of the textbooks used in the teaching of these two courses have an evolutionary orientation. However, a careful examination of the scientific basis of these disciplines shows that the evolutionary framework doesn't fit with a lot of their fundamental aspects. Some of these topics even constitute strong evidence in favor of intelligent design. The objective of this paper is to analyze these topics to see why they provide good evidence that is consistent with a creation model for the origin of life. Issues in Zoology The science of Zoology deals with the study of animal life. The whole study of Zoology is now structured around the theory of evolution, according to which all the present animals would have developed from unicellular common ancestors (protozoa). The present animal taxonomy (classification) is based on phylogeny, i. e., the evolutionary history of a group. Problems in the animal fossil record If all animals developed from common ancestors, ideally, one expects to find several series of links connecting different groups of organisms. However, that is not what we find in the fossil record (Brand, 1997, p.141). Darwin recognized that the fossil record did not show much evidence for connecting links. He thought that as more fossil collecting was done over time, these links would be found. In his book "Origin of species" he says: "Lastly, looking not to any one time, but to all time, if my theory be true, numberless intermediate varieties, linking most closely all the species of the same group together, must assuredly have existed; but the very process of natural selection constantly tends, as has been so often remarked, to exterminate the parent forms and the intermediate links. Consequently evidence of their former existence could be found only amongst fossil remains, which are preserved in an extremely imperfect and273intermittent record" (Darwin, p. 179). "Nature may almost be said to have guarded against the frequent discovery of her transitional or linking forms" (Darwin, p. 292). "Geological research (…) has done scarcely anything in breaking down the distinction between species, by connecting them together by numerous, fine, intermediate varieties; and this not having been effected, is probably the gravest and most obvious of all the many objections which may be urged against my views" (Darwin, p. 299). In the 130 years since Darwin's prediction, many fossils have been collected. This improved database still suggests that, for most animals, the fossil record does not contain connecting links between types (Brand, 1997, p. 143). One of the most important fossil gaps is the one between the microorganisms, such as blue-green algae and bacteria, that are found in Precambrian strata, and the abundant and complex invertebrate sea life of the Cambrian period, as well as the strange Ediacaran fossils of the Precambrian (Morris, 1995, p. 81). Almost all of the phyla of invertebrate animals that have a fossil record occur in the early Cambrian: protozoa, sponges, cnidarians, mollusks, brachiopods, annelids, arthropods and echinoderms. The only major absent phylum is the Bryozoa, which appears in the Ordovician (McAllester, 1971, p. 70). If evolution had really occurred, we should find in Precambrian rocks the evolutionary ancestors of all these animals. According to Axelrod (1958), the high degree of organization of the Cambrian animals clearly indicates that a long evolutionary period preceded their emergence in the fossil record. However, an examination of the Precambrian rocks for precursors of Cambrian fossils indicates they are not found anywhere. The majority of the fossils found in the Precambrian rocks are fossil microorganisms. Only in the top of the Precambrian some multicelular fossils are found. Among them are the Ediacaran fauna, including cnidarians, annelids and arthropods. They are multi-celled animals, but they are not considered ancestral to the Cambrian animals (Gould, 1989; Seilacher, 1984). They are a unique, extinct assemblage of animals with no clear ties to other groups (Brand, p. 143, 1997). If we find fossils of bacteria and blue-green algae in the Precambrian, certainly we should find fossils of the ancestors' of the Cambrian animals. If microorganisms evolved into metazoans, it seems likely that transitional forms should have been found but they have not. The sudden appearance of the274major phyla in the Cambrian has been called the "Cambrian explosion". Recently the estimated time over which the explosion took place has been revised downward from fifty million to ten million years  a blink of the eyes in geological terms. The shorter time estimate has forced sensationalist writers to seek new superlatives, a favorite being the "Biological Big Bang" (Behe, 1996, p. 27). Gould has argued that the fast rate of emergence for new life forms demands a mechanism other than natural selection for its explanation (Beardsley, 1992). Futuyama (1992, p. 343) says that the fast origin of the animal phyla, which happened in the 100 million years between the Ediacaran fauna and the Burgess Shale fauna (Cambrian), has been considered one of the biggest problems of evolution. The theory of separate creation of each group explains the evidence better than the theory of a single


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