The Theory of Evolution Is Valid

I. The Nested Hierarchy of Species My opponent really makes no effort to try and refute this argument; instead, he just claims that other biological systems could also have a nested hierarchy. However, this is not true: "The nested hierarchical organization of species contrasts sharply with other possible biological patterns, such as the continuum of "the great chain of being" and the continuums predicted by Lamarck's theory of organic progression. Mere similarity between organisms is not enough to support macroevolution; the nested classification pattern produced by a branching evolutionary process, such as common descent, is much more specific than simple similarity. Real world examples that cannot be objectively classified in nested hierarchies are the elementary particles (which are described by quantum chromodynamics), the elements (whose organization is described by quantum mechanics and illustrated by the periodic table), the planets in our Solar System, books in a library, or specially designed objects like buildings, furniture, cars, etc. "[1][2]Nothing so organized as this could possibly have come out of any other biological system: [3]Evolution does require a nested hierarchy of species, and this is indeed observed: "Therefore, since common descent is a genealogical process, common descent should produce organisms that can be organized into objective nested hierarchies. Equivalently, we predict that, in general, cladistic analyses of organisms should produce phylogenies that have large, statistically significant values of hierarchical structure (in standard scientific practice, a result with "high statistical significance" is a result that has a 1% probability or less of occurring by chance [P < 0.01]). As a representation of universal common descent, the universal tree of life should have very high, very significant hierarchical structure and phylogenetic signal. "[1]II. Past HistoryMy opponent is basically trying to claim that microevolution exists, but not macroevolution. Even though this debate considers both, this point is wrong on a number of levels because they basically are the same process. "Simply put, evolution is the result of changes in genetic code. The genes encode the basic characteristics a life form will have, and there is no known mechanism that would prevent small changes (microevolution) from ultimately resulting in macroevolution. While genes can vary significantly between different life forms, the basic mechanisms of operation and change in all genes are the same. "[4]Further, "Speciation is distinct from microevolution in that speciation usually requires an isolating factor to keep the new species distinct. The isolating factor need not be biological; a new mountain range or the changed course of a river can qualify. Other than that, speciation requires no processes other than microevolution. Some processes such as disruptive selection (natural selection that drives two states of the same feature further apart) and polyploidy (a mutation that creates copies of the entire genome), may be involved more often in speciation, but they are not substantively different from microevolution. "[5]So in other words, if my opponent believes in the processes of microevolution, he must believe in the processes of macroevolution. If not, then I ask him this simple question - what biological or logical barriers prevent the former from becoming the latter? II. A. AtavismsHaving a true tail is not as common as my opponent thinks: "More than 100 cases of human tails have been reported in the medical literature. Less than one third of the well-documented cases are what are medically known as "pseudo-tails. " Only 100 cases of true tails. That's it. [1]Out of my opponent's already flawed argument, he tries to make the conclusion that it is not a mutation. But, in fact, it is: "Additionally, researchers have identified a mutant mouse that does not develop a tail, and this phenotype is due to a regulatory mutation that decreases the Wnt-3a gene dosage Thus, current evidence indicates that the genetic cause of tail loss in the evolution of apes was likely a simple regulatory mutation(s) that slightly decreased Wnt-3a gene dosage. Conversely, a mutation or environmental factor that increased dosage of the Wnt-3a gene would reduce apoptosis of the human tail during development and would result in its retention, as an atavism, in a newborn. "[1][6]Overall, "The vestigial tailbone in humans is homologous to the functional tail of other primates. Thus vestigial structures can be viewed as evidence for evolution: organisms having vestigial structures probably share a common ancestry with organisms in with organisms in which the homologous structure is functional. "[7]II. B. Common Anatomies While Haeckel's original drawings were flawed, there is a common embryo form: [8]Even if there weren't any resemblances between the embryos, "All vertebrate embryos use these Hox genes to define their body plan. One surprising result of molecular approaches to development is that it seems that all multicellular animals, everything from worms to insects to mammals to jellyfish, use this same spatially organized array of homeobox-containing genes to define their layout. There are differences: vertebrates seem to have duplicated the array a few times, so that they have four copies of the set of Hox genes, while Drosophila (in which these genes were first identified) has a single cluster; mice and humans have 13 Hox genes in each cluster, while Drosophila has 9, and Hydra has 2. The universality of these genes in animal development has led to the concept of the zootype, or form that links all animals, rather than just the embryos of a single phylum. "[9]: So files have a lot of the same body structure as mice. "All animals examined so far have been found to have this same map of positional information encoded in their genome. "[9]II. D. Relatedness All animals are technically related to one another, but some are more strongly related than others. "Matches in base sequence between species indicate a high degree of relatedness. For example, in the figure on the right you can see that more matches are made between a human and a chimp than between a human and a chicken. This indicates that the human and the chimp shared a more recent common ancestor than the human and the chicken and are closely related. "[10]: So yes, cats and whales are related to primates, but they are not primates themselves. On the falsificationism claim, there have been cases where supposed relatedness was actually found to be false. Some of the cases in On the Origin of Species have been fraudulent. Conclusion The theory of evolution has been proven time and time again through reliable tests to be true. No other biological system could possibly produce the nested hierarchy of species that we see. In addition, evolution is true, but some of its predictions can be, and have been falsified over the years, making it a true valid scientific theory. It has stood the tests of time and extreme scrutiny, and is one of the most important theories ever hypothesized. Sources [1]: . http://www.talkorigins.org...[2]: Futuyma, D. (1998) Evolutionary Biology. Third edition. [3]: . http://www.talkorigins.org...[4]: . http://atheism.about.com...[5]: . http://www.talkorigins.org...[6]: Greco, T. L. , Takada, S. , Newhouse, M. M. , McMahon, J. A. , McMahon, A. P. , Camper, S. A. (1996) "Analysis of the vestigial tail mutation demonstrates that Wnt-3a gene dosage regulates mouse axial development. " Genes Dev 10: 313-324. [7]: . http://bioweb.cs.earlham.edu... [8]: . http://www.discovery.org...[9]: . http://www.talkorigins.org...[10]: . http://www.citruscollege.edu...NOTE: Sources 2 and 6 are quoted from source 1.