Evolution

This is a full affirmative argument. I will focus the rest of the debate on addressing Con's criticisms and adding in necessary details that he may request be expounded upon. The Case for Evolution: In light of the discoveries of the sciences of biology, chemistry, geology, and physics, the evolutionary theory provides the best possible explanation for the origin and development of life on Earth. [1] The Earth is estimated to have formed 4.4 billion years ago, and was absolutely antagonistic to life for the majority of the time since them. [2] Now the Earth flourishes with life and is the home of an advanced technological civilization. This momentous change was the resolute of eons of geologic and (as this discussion will stress) biological activity. About 3.5 billion years ago, the first semblance of organic life began to develop. [3] It was initially comprised of simple organic compounds such as amino acids and nitrogenous bases. [4] These compounds have been observed to form naturally under the right conditions. [5] In the 1920's, British and Russian scientists hypothesized that the early-Earth atmosphere was reducing, producing perfect conditions for the formation of organic compounds. This hypothesis under laboratory conditions at the University of Chicago and the experiment produced a huge number of organic chemicals. Alternate theories positing that volcanic activity could have produced the right conditions have been tested and found plausible. [7] The formation of more complex systems from these basics proceeds fairly logically. The building blocks of more complex organic compounds eventually arrange into proteins and nucleic acids. A 2009 experiment demonstrated that RNA, the basic genetic compound, can be synthesized abiotically from basic precursor molecules. Researches were also able to synthesize polymers by dripping solutions of amino acids and RNA nucleotides onto hot sand or clay. This did not require the assistance of enzymes or ribosomes. Some of these polymers could actually act as weak catalysts themselves, forming the basis for further cell infrastructural development. [8] This of course leads to the question of how cells themselves formed. This is an easily answerable concern: vesicle self-assembly results from lipids, which have both hydrophobic and hydrophilic components, arranging into a membrane such that the hydrophobic ends are on the inside. These membranes have limited permeability and can create an internal environment quite chemically different from the external environment. The addition of the clay montmorillonite, a common volcanic ash, increases the rate of vesicle formation exponentially. Complex vesicles have been shown to 'reproduce', exhibit selective permeability, and carry out basic metabolic functions. [9] Some RNAs, which play a major role in protein synthesis, also can carry out catalytic functions. These RNAs are called ribozymes, and can make copies of short pieces of other RNAs provided that they have the nucleotide building blocks. Natural selection on the molecular level has produced self-replicating ribozymes under laboratory conditions. This occurs because some RNA molecules are better suited to copying under certain conditions. Occasionally, a copying error occurs that makes the RNA even better suited to copying than its predecessors. [10] Such RNA molecules could carry information about vesicles the carried them and be spread to daughter vesicles as the carriers divided. At first they would only have specified a few traits, but over time the traits would have become more and more complex and numerous. Once the need for self-replication could be fulfilled by proteins, the more stable DNA could replace RNA as the genetic code. Once self-replicating and self-regulating vesicles emerged, there was no stopping the rapid diversification and growth of cellular life. [11] The transition from unicellular to multicellular life is readily visible in the diversity of life today. We see single celled organisms, small groups of cooperative cells, and cell colonies that become more and more interdependent until they become one organism. From this we can see the variety of all multicellular life, from the simplest hydra to the most complex vertebrates. [12] I have a limited amount of room, so I have left out many important details in the history of life, focusing on the aspects I deemed most important. I can explain the existence of organelles, the eukaryote/prokaryote split, or specific events later on if necessary. It looks like Con's argument will demand discussion of the Cambrian explosion. In the interest of space, I will skip any discussion of genetics and the basics of microevolution (natural selection, descent with modification, etc.) and go right into macroevolution. If the macroevolution discussion depends on these topics then I will go back to them. Macroevolution refers to evolutionary changes that occur above the species level. It can refer to speciation and to broad trends in life that may occur. [13] Macroevolution is the cumulative effect of microevolution occurring on a grand scale over a long period of time. To accept microevolution is necessarily to accept macroevolution: there differences between the two exist in degree and not in principle. Speciation simply occurs when reproductive barriers result from continued genetic isolation, there is no magic to it. Some species can reproduce with one another, but their internal genetic pools are almost entirely self-contained. [14] The idea that evolution has occurred over time to produce the multitude of life on Earth is supported by an overwhelming body of evidence. Organisms have homologous structures, which are aspects of their physiology that are very similar to those of other species but differ greatly in function. This suggests that they share a common ancestor and were modified over time. They also have vestigial structures; structures that once served a function but no longer do. The similarities between different species are even stronger during embryonic development and on the chemical level. The uniformity of the chemical composition of life provides overwhelming evidence for common descent. [15] It is not nearly possible to describe the theory of evolution entirely in 8000 characters. I could write 100 times this much and not be done, but that is a research project I have neither the knowledge nor the time to undertake. This explanation of evolution is beyond the level of analysis that most Creationist ever bother to go into, and I was able to support all of it using only a few chapters from a borrowed 101 level biology textbook and Google. The support for evolution is unbelievably immense, and as I will demonstrate in the following rounds there is a crushing rejoinder for every argument that could possibly be brought against it. The science of biology and the practice of medicine are heavily based in evolutionary theory. To understand biology not just in terms of pure facts but also in terms of the mechanisms that govern the function of all life, one must have a rigorous understanding of evolution. The structure and function of all life is described and understood more deeply and thoroughly as a result of the theory of evolution. The theory of evolution is surely among the most important advances in the history of human thought. That some people continue to reject it in favor of a traditionalist worldview that is not grounded in facts or logic is a great shame. Sources: All are from Campbell's Biology, 9th Edition, by Reece et al. except for these two: [2] http://en.wikipedia.org... [5] Chemistry: The Central Science, 8th Edition, by Brown et al. I won't bother citing page numbers because it's not like you guys have those books. I'm just verifying that these books exist and that I didn't just make that up. If you prefer, pretend I'm so smart that I didn't need to look any of that up.