The Current Theory of Evolution is a Scientific Theory

Hi! First, let"s start with the Theory of Evolution. The Theory of Evolution was proposed by Charles Darwin in his book On the Origin of Species (1859) in which he postulated that a process called Natural Selection (defined as "the process whereby organisms better adapted to their environment tend to survive and produce more offspring.) was the main mechanism behind the incredible variety of plant and animal life on our planet. However, Darwin did not know what caused the appearance of beneficial traits in species, changes that eventually lead to different species and overtime, the variety of life on this plant. That question was answered by the discovery of genes, DNA, and the DNA-to-Protein process. Thus here is the Theory of Evolution in its form today: When species reproduce, changes in their offspring"s DNA (via mutations, translocations, epigenetic modifications, etc.) lead to changes in the proteins, and hence traits those offspring express. These changes can be harmful, neutral, or beneficial depending on the nature of the change. Often such changes can ambivalent- good in one environment, bad in another. Of these offspring, those with the most beneficial traits for their environment will have greater survival chances, and thus more opportunities to mate and pass their new genes to the next generation where the process is repeated. In other words, natural selection. Over time, if a trait is beneficial to survival in that particular place, it will slowly (or quickly depending on the circumstances) become more prevalent in the population inhabiting that particular place. However, often an original species is becomes spread over multiple different environments, and thus traits that are beneficial in one place, aren"t in another, and vice versa. This leads to different subgroups of the species developing different traits to cope with their different environments.Overtime, these different groups within the species, via natural selection, acquire enough traits to be considered a different species. This process- species dividing into different ones based off their different environments, is called speciation, and there are several types: Allopatric speciation is when two or more groups of the species are separated by a physical barrier (mountain, river, etc.) and so select and evolve differently (peripatric speciation is similar). Parapatric speciation is when the species is spread over such a large area that they develop different traits and eventually new species because of the variety that accompanies such a large habitat. As this goes on and on, species that were once the same become entirely different through billions of years of environmental changes, adaptations, and generations. It is the process of DNA changes to new traits to natural selection to speciation that causes the plethora of plant, animal, and bacterial species we see today. Now that we know that basic outline that the Theory proposes, lets look at what it would predict. After all, a good theory makes definite predictions that can be proven wrong if tested. First, the theory demands a large timescale, on the magnitude of millions of years (this is why people at first didn"t think it was correct, because the bible said the world was young, I believe the figure was 6000 years old). Second the theory demands a mechanism in which organism could change their traits from generation to generation (it demanded this before genes were discovered). Third, it would dictate the as a general rule, organisms that were predicted to diverge more recently in evolutionary history would have more similarities in a number of different ways (DNA, embryo development, etc.). Finally it would predict that all life formed from a a soup of inorganic molecules during the early formation of the earth (if every animal came from a previous animal, then there had to one or more very primitive organisms that formed out of inorganic molecules that the rest of the animals descended from). To test, and subsequently prove or disprove a theory, one has to test these predictions. A theory with untestable predictions, or is so general that it can not be tested at all, is not a true theory. Thus, let"s see what happened when people tested evolution. Let"s start with the timescale. Though in Darwin"s time, the heat generated from radioactive decay of elements in the earth was not known, and thus temperatures measured by geologist put the earth as too young for his theory, nowadays we can adjust for this and results are in favor of evolution. According the United States Geologic Survey "The oldest rocks on Earth, found in western Greenland, have been dated by four independent radiometric dating methods at 3.7-3.8 billion years. Rocks 3.4-3.6 billion years in age have been found in southern Africa, western Australia, and the Great Lakes region of North America. These oldest rocks are metamorphic rocks but they originated as lava flows and sedimentary rocks. The debris from which the sedimentary rocks formed must have come from even older crustal rocks. The oldest dated minerals (4.0-4.2 billion years) are tiny zircon crystals found in sedimentary rocks in western Australia." (For more evidence and information on the radioactive elements used for the dating, visit http://geomaps.wr.usgs.gov...). Thus, theory demanded and predicted a very large timescale, and was correct. Even in its earliest form, the one proposed by Darwin himself, required organisms to have some sort of mechanism of changing and acquiring new traits from generation to generation. In a way, evolution predicted DNA, a blueprint for an organism that could be changed, manipulated, added onto and subtracted from, because it needed a mechanism for variation that had just such capabilities. Again the theory was correct. Though the theory would predict evolutionarily-related organisms will share similarities, the fact it was formulated to explain such similarities and differences that Darwin observed makes using such pieces of evidence a bit dicey. In this case, evolution is tested by throwing different observed phenomena at it and seeing it would or would not predict it. However, instead of cataloguing every single observed fact that evolution describes, I"ll try to catalogue the main classes of phenomena evolutionary theory explains. Embryology: The way embryo"s form makes sense when it is applied to the model set forth by evolution. As you go down the taxonomic ladder, embryo of the organism"s look similar and similar. Additionally embryo"s devolopment provides a little window into evolution processes. For example: "One of the most celebrated cases of embryonic homology is that of the fish gill cartilage, the reptilian jaw, and the mammalian middle ear (reviewed in Gould 1990). First, the gill arches of jawless (agnathan) fishes became modified to form the jaw of the jawed fishes. In the jawless fishes, a series of gills opened behind the jawless mouth. When the gill slits became supported by cartilaginous elements, the first set of these gill supports surrounded the mouth to form the jaw. There is ample evidence that jaws are modified gill supports. First, both these sets of bones are made from neural crest cells. (Most other bones come from mesodermal tissue.) Second, both structures form from upper and lower bars that bend forward and are hinged in the middle. Third, the jaw musculature seems to be homologous to the original gill support musculature. Thus, the vertebrate jaw appears to be homologous to the gill arches of jawless fishes." (for further reading and more evidence go to: http://www.ncbi.nlm.nih.gov...) I will continue my arguments in the comments, as I have a LOT to say. As I will post in order, when you view them, you will see the end of my argument first, then as you scroll down you will reach where I left off (next is the fossil record).