Evolution: The ramfications of multiple mutations And the necessity for Informatio.

I'm glad CON has abandoned his argument from abiogenesis, unfortunately, he seems to have misunderstood the explanation I gave about useful intermediates and the examples of observed macroevolution taking place. I'll try to make my meaning more apparent. Hopefully by clarifying these issues, I can convince my opponent of my position. ========= REBUTTALS ========= C1- Irreducible Complexity My opponent writes: "a wing without nerve connections would serve no purpose at all." Complex structures, such as limbs, do not suddenly emerge fully formed; they develop from earlier, simpler structures. Arms are believed to have evolved from fins, specifically from pectoral fins. The pectoral fin evolved through a repositioning of pre-existing pelvic fins through a mutation of its homeotic gene.[1] Pelvic fins, in turn, evolved from simpler pelvic flaps. In the gradual process from pelvic flap to pectoral fin, the necessary bones, muscles, tendons were each developed gradually. Though it's impossible to be sure exactly how it happened, it probably occurred something like this: first came nerves that allowed the fish to receive sensory input from the appendage. Muscles were then adapted from other purposes to allow a limited manipulation of it. Cartilage formed within the structure, giving it greater rigidity. Eventually, the cartilage became bone. The sarcolemma of the muscle fibers became elongated, making them more effective. These later became tendons. With all this in place, the transition from pectoral fin to leg was rather simple, in fact, we have transitionary fossils showing it.[2] Tiktaalik roseae is a prehistoric fish with several traits found in reptiles, among these, tiny feet in the pectoral region. This brings us to CON's second objection, the development of mammalian reproduction. CON names three important traits: live birth, mammary glands, and feeding instincts. CON claims that having any one of these, without the others, would cause the animal to die out quickly. This is must certainly not true. The platypus does not give birth to live offspring, yet it possesses mammary glands that its young feed off of.[3] Moreover, there is no reason to believe that live birth would necessitate breast feeding. Of these three traits, it's believed that mammary glands came first. Endothermic reptiles, possibly with hair or fur -- precursors to modern mammals -- probably developed bare, vascularized patches of skin used to facilitate the incubation of their eggs. These warm blooded animals likely had various skin glands used to radiate heat and keep their fur soft and pliable. With the development of internal body heat, the risk of bacterial growth increased, so it seems logical that these glands adapted to produce antibacterial and antiviral secretions to protect the skin and the eggs. At some point, these secretions may have supplemented the nutrients contained in the developing embryo's yolk sack. Over time, they may have grown and become more specialized, allowing the hatchlings to nurse.[4] Viviparity may or may not have developed in conjunction with breastfeeding. Regardless, we have a pretty good idea of how it happened. Chicken eggs typically spend one day in utero, followed by 21 days of external maturation. Platypus eggs, by contrast, spend 28 days in tract and only 10 in external incubation.[5] The evolution of live birth is simply a matter of eggs spending more time developing in the uterus. Saiphos equalis, or the common skink, a small snake-like reptile from southeastern Australia appears to be in the process of developing viviparity before our very eyes. Skinks living in the highland regions give birth oviparously, while skinks in the coastal region give birth viviparously. Even the viviparous skinks have not completely left behind their oviparous past -- baby skinks are born encased in a gelatinous membrane that they break out of within about 36 hours.[6] ========= CASE PRO ========= C1- Vestigial Structures I'll be brief here, since my opponent's objection is a simple matter of misunderstanding. It is not that scientists cannot conceive of a purpose for structures such as the tiny femur bone found on whale skeletons completely hidden from external view; they did have a purpose sometime in the animal's evolutionary past. The issue is that they no longer serve that purpose, they remain merely as reminders of their former use. It does not require omniscience to see this; these remnants of hind limbs are immobile, bound by strong ligaments and with the hip joint fused into one piece.[7] In the rare instances (about 1 in 100,000) where they protrude visibly form the body, the drag they create in the water actually hinders the animal.[8] C2 - Observed Instances of Speciation Again my opponent's objection is merely a misunderstanding. He writes: "if I do understand your second example, you state that obtaining different characteristics with reproduction is impossible as it gives sterile infants." This is incorrect. In the study I cited, the copper resistant plants were perfectly capable of reproducing with other copper resistant plants; it was when attempts were made to crossbreed them with the non-resistant plants that problems arose. The same is true of the fruit fly example. Flies that were bred together for multiple generations under similar temperature and humidity conditions were able to breed with eachother, but were not able to interbreed with populations bred for multiple generations under different conditions. == CONCLUSION == By explaining the development of limbs, viviparity, nursing, and other processes, I have dismantled my opponent's primary argument from irreducible complexity. In doing this, I have also given examples of transitionary fossils and instances of evolution taking place in the world today, thus strengthening the affirmative case. I eagerly await my opponent's reply. Thank you, the resolution has been AFFIRMED. -- References -- 1. Young et al. "Cdx and Hox genes differentially regulate posterior axial growth in mammalian embryos." Dev. Cell 17 (4): 516–26. October 2009. 2. Shubin et al. "The pectoral fin of Tiktaalik roseae and the origin of the tetrapod limb. Nature 440(6): 764-771. 2006. 3. "Platypus." Environmental Protection Agency/Queensland Parks and Wildlife Service. 2006. http://www.epa.qld.gov.au.... 4. Blackburn et al. "The origins of lactation and the evolution of milk: a review with new hypotheses." Mammal Review 19: 1- 26. 1989. 5. Cromer, Erica. "Monotreme Reproductive Biology and Behavior." Iowa State University. 2004. http://www.biology.iastate.edu.... 6. Stewart, et al. "Uterine and eggshell structure and histochemistry in a lizard with prolonged uterine egg retention." Journal of Morphology, n/a. doi: 10.1002/jmor.10877 7. Struthers, John, M.D. "On the Bones, Articulations, and Muscles of The Rudimentary Hind-Limb of the Greenland Right-Whale (Balaena mysticetus)." Journal of Anatomy and Physiology (London), Vol. 15, p. 141-321. 1881. 8. Wilford, John. "Whales' Hind Feet Show Up in Fossils." The New York Times. 1990. http://www.nytimes.com...