Evolution v. Creation

I agree with my opponent that the corollary of creationism is that God exists. However, we will leave it at that. EVIDENCE FROM OUR BODIES In a famous paper published in 1973, Theodosius Dobzhansky stated, “Nothing in Biology Makes Sense Except in the Light of Evolution. ” (Dobzhansky, 1973) In this section, and throughout the debate, we will see that his words are as true today as they were back when they were first written. VESTIGES AND ATAVISMS Some of the most interesting lines of evidence for evolution lies in vestigial structures and atavisms. First, we need to define our terms. A vestigial structure is defined as an anatomical structure in which the original function is absent or reduced. (Fairbanks, 2012) Before I continue, I wish to make this clarification: a structure does not have to be functionless in order to be a vestige. As Phil Senter wrote in the Journal of Zoology: “[A] structure is considered vestigial if, in comparison with its homolog in at least three successive outgroups, it is reduced to one-third or less its size relative to adjacent structures and if at least distally it has lost the specialized morphology present in three outgroups. ” (Senter, 2010) On the other hand, an atavism is the reappearance of a lost character specific to a remote evolutionary ancestor and NOT observed in the parents or recent ancestors of the organism. (Theobald, 2012) There are many such cases of vestigial structures such as remnants of sightless eyes – often buried under the skin – in cave fish and marsupial moles, small hind limb bones in whales and some snakes, dew claws on dogs, and a splint bone in horses. (Fairbanks, 2012) These are very interesting from a Creationist perspective. Why would God go through all that trouble and create sightless eyes? However, this makes perfect sense “in the light of evolution. ” In humans, goose bumps are a remnant of the past. Goose bumps form on your skin when tiny arrector pili muscles in the skin contract. The function of the goose bump is to raise hairs to better insulate the animal when the air is cold, or to make the animal look larger and more menacing when frightened. Although they do rise, they do very little for that purpose! (Fairbanks, 2012) There are also many good cases of atavisms such as humans born with tails and living whales with legs! (Theobald, 2012) Why would whales even have the gene to make legs if they were specially created, let alone are sometimes born with them? EVIDENCE IN THE GENOME HUMAN CHROMOSOME 2 AROSE FROM A FUSION OF TWO ANCESTRAL CHROMOSOMES All great apes have 24 pairs of chromosomes, but humans have only 23. Therefore, if we share a common ancestor with the great apes, there ought to be a fusion between two chromosomes. The second chromosome in humans is actually a fusion between two ancestral chromosomes. What is more impressive is that the fusion is right where we would expect it to be had two ancestral chromosomes fused with each other head-to-head at their telomeres. PSEUDOGENES A pseudogene is a segment of DNA resembling a gene but lacking genetic function. In other words, it is a segment of DNA that is disabled. (Fairbanks, 2012) “Humans do not have tails, but do we have “what it takes” for a tail? Hens don’t have teeth, but they have the genes for it. With atavism, it is as if our genomes serve as archives of our evolutionary past. ” (Jill U. Adams, 2009) If creationism as my opponent believes it to be is true, then why do chickens retain the gene for making teeth and humans the gene to synthetically produce Vitamin C? Some pseudogenes are actually beneficial. As Daniel J. Fairbanks notes in his book (Fairbanks, 2012) Malaria is one of the most horrific human diseases. However, at one point in our evolutionary history, humans enjoyed immunity to malaria. What happened for humans to gain and lose resistance to malaria? Malaria is caused by a microorganism known as Plasmodium falciparum. It cannot be transmitted from person to person but must be carried via a mosquitoes and acquired and transmitted when a mosquito bites a person. Chimpanzees suffer from a less severe form of malaria caused by a microorganism called Plasmodium reichenowi. What happened is the following: The human parasite evolved from the chimp parasite by jumping hosts from humans to chimpanzees. Plasmodium reichenowi recognizes a substance on a gene called CMAH. Our genome carries this gene and we have it in the same strand of DNA as chimpanzees do. However, the only difference is it is disabled – a pseudogene if you will. No-one has the original non-mutated version. The mutation that disabled the CMAH gene had a distinct advantage of those that did not – they became resistant to malaria. So, what happened? Why did we lose our resistance to malaria? The answer lies in the evolution of malaria itself. Mutations in a gene called EBA-175 allowed those parasites that carried the same mutation to recognize another substance which is abundant on human red blood cells about five to ten thousand years ago. The results: Plasmodium falciparum evolved as a new species. We are highly susceptible to this new form of malaria and the new version of malaria is much worse than the old one. That is all the time I have for today, I will expand and post other arguments in the next round. _____________________________________________________________ Bibliography Dobzhansky, T. (1973, March). Nothing in Biology Makes Sense except in the Light of Evolution. The American Biology Teacher, Vol. 35, No. 3, 35(3), 125-129. Fairbanks, D. J. (2012). Evolving: The Human Effect and Why it Matters. Amherst, New York: Prometheus Books. Jill U. Adams, P. &. (2009). Atavism: Embryology, Development and Evolution. Retrieved from Nature: . http://www.nature.com... Senter, P. (2010). Vestigial skeletal structures in dinosaurs. Journal of Zoology, 280(1), 60-71. Theobald, D. L. (2012). 29+ Evidences for Macroevolution: The Scientific Case for Common Descent. Retrieved from The Talk. Origins Archive: . http://www.talkorigins.org...