Did you happen to read the post while you were quoting it. I said that the intermediate stages that have yet to produce the eye do not carry a competitive advantage. Also are you sure that those are not subspecies of the same species of bird(some sort of finch I think). And what if every once in a while some terrorist blew up the building where the monkey was typing(mass extinctions) that would add even more iterations until the correct sequence was reached. Don't be too ready to dismiss the "earth is not old enough" argument. ------------------ Don't come in Bullard's house! [This message has been edited by Hydra (edited February 27, 2001).]
Im not trying to readily dismiss the earth is not old enough example. I just know that it is an old, religion-based and religion-pushed argument. And each time they found that the earth was actually older than previously thought, they just pushed back the argument. "Oh, so now the earth is millions of years old instead of the few thousand we thought. Well maybe insects evolved then but not people, no way, we're too special...What, now the earth is billions of years old. Hmmm, well maybe other primates evolved, but definitely not humans, God put us here for a special purpose." Anyway, the intermediate stages that have yet to produce our human eye DO carry competitve advantages. Each step has a competitive advantage over the previous one. From what I gather, you understand my argument for intermediate steps, but you dont think they are favored by selection? After all, what good is 5% of an eye? Well, 5% of an eye is better than no eye at all. Many invertebrates have a simple light sensitive spot. Photoreceptors of this kind have evolved many times from ordinary epidermal (surface) cells--most of the time ciliated cells whose biochemical machinery is light-sensitive. When information about changes in light sensitivity are useful, the the invertebrates are favored. It is easy to imagine how the toad who can distingusih between light and dark has an advantage over the toad with no eye at all. So the intermediate stages that have yet to produce the human eye do carry competitive advantages (mutations can cause these beneficial changes in the first place which are then selected for). Catastrophic events do occur. This is of course how they thought the dinosaurs became extinct. There is no direct fossil evidence of the existence of primates prior to 60 million years ago. Current evidence shows the hominid chain breaking off about 5 million years ago. Catastrophes do occur. Catastrophism was first thought up by a man named Cuvier(1769-1832), who is also known as the "father" of paleontology. Interestingly, Cuvier was very religious, and thus beleieved in immutability, but nonetheless couldnt figure out a way to describe all the strange looking fossils he found (hence his idea for catastrophism). While catastrophes occur, they do not make evolution impossible. Uniformitarianism, an idea by Charles Lyell (1797-1875), a British geologist, is the philosophy Darwin used. Lyell studied rock formations (think of the Grand Canyon) and realized that the geographic landscape we see today is more likely a result of the incremental effect of processes that are still going on today (wind and rain erosion, etc). Catastrophes occur, but there is still time for evolution to take place and for humans to evolve (evolution has us evolving from monkeys in only 5 million years and the earth is over 4.5 billion years old). Also, the Finches on the Galapagos are considered to be seperate species. You can argue that they are not, but then it just becomes an argument of classification. Are apes and chimpanzees different species? Linnaeus' taxonomic system says yes. The Finches are a very interesting study. There are 14 species and evidence suggest that all 14 are descended from a single South American species that migrated to the islands about half a million years ago. This doesnt seem like too long for 14 different species to evolve. Nonetheless, experiments done by the Grants over the past 20-30 years prove its possible. They studied the effect of a serious drought on the island on one species of birds. In just one generation they documented enourmous changes in beak size and width as a result of natural selection taking place (they ratio of small seeds to large, hard seed changed drastically). In fact, if a "catastrophe" such as the drought that happened in 1977 on the Galapagos occured only once every centruy, it would only take 2000 years to transform the species into a new species of ground finches. Another example deals with a population of elk (red deer). 100,000 years ago these elk colonized and then became isolated on an island of Jersey, on the French coast. By the time the island was reconnected with the mainland only 6000 years later, the red deer had shrunken to the size of a large dog. There are many other examples of evolution of species. Now, of course there is no documentation of, say, a toad evolving into a monkey, because evolution doesnt work that way. It acts ont he individual and it acts in small steps. But as each step occurs, eventually you get different species and different species until you end up with a wide spectrum of species, from human to whale, etc, etc. ------------------
The last part is where your evidence chain runs out. Sure a bird can change its beak size, or an animal can grow larger or smaller. We breed greyhounds to be fast runners. But we cannot breed greyhounds to grow wings and fly. There is evidence to support an animal adapting to its environment. Where is the evidence of a plant becoming an animal, a sea creature becoming a land creature, the origin of mammals, or any other major evolution. From what I have seen, the only evidence that new species evolve is that they once did not exist and now they do. The same fact can also be used to support creationism. Secondly, not every gene produces an advantage. Sometimes it takes multiple genes in concert, but if the first does not produce any advantage, it is no more likely to be passed on than any other. This makes recieving the other genes later moot because you need them all. Finally, I am not saying that insects may have evolved or that primates may have evolved. I am saying that life on earth likely did not evolve through mutation and natural selection from some pool of protiens that was here when the world was formed. I believe that God set the course for the evolution of species, and/or introduced different lifeforms when and how he saw fit. ------------------ Don't come in Bullard's house!
No reputable person in the world, including myself, has every proposed the direct evolution of dog to bird--thats why I said in my previous post Now, of course there is no documentation of, say, a toad evolving into a monkey, because evolution doesnt work that way. It acts ont he individual and it acts in small steps. But as each step occurs, eventually you get different species and different species until you end up with a wide spectrum of species, from human to whale, etc, etc. Is it possible that birds and dogs, very very very far back have the same common ancestor, though....I think so. It is only over million and millions of years that they have each evolved seperately, through mutation and other processes. And you are right about polygenetic traits. There are many other things you can bring up, such as the existence of introns, or the fact that many codon triplets code for the same protein, etc, etc. There are many little quirks like this. And like you, I agree that God plays a role at some point. I just see his/her/its role to be smaller. I dont think God intervenes much and I dont even think God started the prociess on earth, or that God even started the process of the Univers (maybe there is something bigger than the universe that were just part of), but I do think God plays a role at some point. And I think every day, as new discoveries are made, the evidence for natural selection and evolution become more and more overpowering. You will never see the direct link from animal to plant. But evolution doesnt argue for a direct link, or jump, just for small steps(as Ive stressed repeatedly) that eventually get you there so its lack is inconsequential anyway. ------------------
But you don't see any connection, even through hundreds of steps, between an animal and a plant. People talk about the missing link between man and ape. Where are the broccoli people that can cover this gap. Also I was not saying that a dog evolved into a bird. I am merely suggesting that there is no apparent evidence that an animal of the species genus carnivorus could ever develop into anything else. Where did wings develop from, and until they allowed for flight, what was their competitive advantage? There are way to many unanswered questions to even say evolution from a common ancestor is likely, let alone proven as this thread states in the title. ------------------ Don't come in Bullard's house!
Look at the link between bat wings and human hands. You might be interested to know that the structure is the same in both. The bones types found in the human hand are the same found in the bat wing. Yet, the bat uses the structure to help it fly while the humans cant fly on their own at all. They use it for a totally different purpose. Structures like this are known as homologous structures. There are other examples. ------------------
So Hydra- Are you saying you don't believe in evolution at all, on any level? Or are you saying that you just don't believe that everything evolved from one common ancestor? Even though I don't believe in creationism as an end all solution to this question, I see how BOTH creationism and evolution could be the solution. In other words, some god could have created primordial oozes (more than one ooze just one) or whatever you want to call it and then, depending on the various environmental niches, the ooze(s) could have evolved into say two species to fill those niches. Those two species could have evolved into thousands of others over time because of environmental change and the development of new niches. Similarily, as some environmental niches disappeared, the animals or whatever filling those niches could have either adapted to new niches or simply become extinct. Why couldn't there have been more than one type of ooze from which plants and animals evolved? As to how that ooze got there- it could be created by a god or simply random. I happen to believe in the last- you believe what you want. On another note, one possible advantage for the evolution of wings would be that they would allow smaller reptiles (the first in the fossil record to not only have wings but also feathers) to escape from larger reptiles/animals/whatever that would chase them for food. Ali ------------------ Poopy!
Furthermore, on a strictly osteological level, human phalanges and sheep phalanges are remarkably similar. ------------------ Poopy!
Ok, I thought of something else. To think that true archaeology has only been around for about 150 years, we have come a LONG way. My point here is that there is still a massive amount of information YET TO BE DISCOVERED. Furthermore, the archaeological record is being destroyed at an alarming rate. The market for antiquities (including bones of dinosaurs and rare artifacts from all over the world and the U.S.) is astronomical. The laws preventing the movement of these antiquities in and out of the U.S. (one of the largest markets) are ineffectual at best. My point here, to spell it out clearly, is that as amateur archaeologists, poorly trained archaeologists, laymen, and simple looters continue to destroy the archaeological record in search of artifacts (versus the archaeological search for information), the less likely any possible solution for the question of evolution will ever be found, assuming, of course, that there is a solution to be found that will show up in the archaeological record and that there are missing links. I believe there are, but, hey, I'm not that religious and I'm going to eventually be going to graduate school to study human evolution. Ali ------------------ Poopy!
I don't believe in RANDOM evolution, evolution through genetic mutation and natural selection. Evolution that is GUIDED by a supreme beingis much more feasable. For all of the millions of viable species that exist on earth to just be random permutations of some genetic stockpile would simply take too long to come about without the guidence of a supreme being. Ali, What was the advantage of pre-wings(wing like appendages that were not capable of producing flight). If an animal loses the use of half of its legs, but does not get to fly in return, wouldn't it die before it could procreate for enough generations to develop into a flyer. ------------------ Don't come in Bullard's house!
If the animal loses use of half its leg and doesnt get to fly, and had no other benefits from this adaption/mutation, then it would die off and not procreate. More likely, however, there was a benefit from the variation and thus it was retained. It is the same as the eye example. What good is 1% of a wing? There are many possible explanations. Perhaps it allowed the animal to hop slightly higher to get food of a plant, or to avoid danger. Perhaps the new look was favored by females and thus selected for sexually. There are many possible reasons. It is presently impossible to say exactly why, but unless God comes down and said I gave animals wings so that they could fly, evolution by some supreme beings control wont ever be proven. ------------------
First of all, evolution is not random. The FIRST instance of evolution MIGHT have been random, but the rest were in responses to the environment and to fill new and unique niches as the environment changed over millions of years. And, yes, it has changed drastically. Just imagine that Chicago was at one point under two miles of ice sheets. Second of all, pre-wings might have been an advantage because they could have allowed the reptile or animal to hop farther than just running would or it could have allowed the reptile/animal to manuever better, allowing it to escape its enemy. Furthermore, the creation of wings does not presuppose that legs get smaller. Legs getting smaller in reptiles could have become an evolutionary adaptation as the wings became more developed. More than likely, though, the legs did not get smaller right away as pre-wings and wings developed. If the legs got smaller and the animal did not get to fly in return, there are millions of possibilities. But it all comes down to the animal's adaptation to the environment. If it was advantageous to have smaller legs and no wings, then it could survive. This might even be what happened in the development of snakes, for example, because they still develop legs, but they are functionally useless, like humans' appendices. If it was not advantageous to have smaller legs and no wings, the animal more than likely died out because there was no environmental niche to fill. Ali ------------------ Poopy!
Hydra, JZ and I are giving you a gross simplification of evolution. To say that only one factor contributed to a species development is a fallacy. In reality there are many factors including preexisting flora and fauna, environment and its changes, sexual preference, etc. Suffice to say that evolution is a very complicated process that varied from region to region and from species to species. ------------------ Poopy!
The idea behind natural selection is that it is random. An animal cannot change its genes to adapt to the environment. Anything that animal can change to adapt would not be passed on to offspring, genetically. Natural selection is simply the idea that, through random genetic mutations of animals, advantageous traits are maintained and passed on from generation to generation until new species are formed. But any mutation of the genetic code, helpful or not, is completely and utterly random. It would be nice if we could change our genetic code by just thinking about it... then all my kids would be white Hakeem Olajuwons! ------------------ "all your base are belong to us!" "you have no chance to survive make your time!"
I'm the first to admit that I don't know a lot about genetics (but I will probably learn if I go to grad school ). But let me clarify my earlier statement. CHANGES might be random (like if a child of mine was born with six toes on one foot), but if that change is not advantageous and the reptile/animal/whatever with that genetic mutation does not reproduce, no evolutionary adaptation will occur. Do ya'll see what I'm saying? There is a difference between random genetic mutations and adaptations. If the six toes on one foot made my child undesirable or gave it some sort of disadvantage, it would more than likely not reproduce. HOWEVER, if that random change/genetic mutation was advantageous and allowed one specific reptile/animal/whatever to reproduce more than its fellow beings or gain more food than its fellow beings, it will have adapted to its environment, creating an evoultionary adaptation that was not random, but in response to outside forces. I feel like I'm not being clear here, so let me think on this and if I come up with a better way to say it, I will. Really what I am trying to say is genetic mutation is random, but evolution is not. ------------------ Poopy!
Makes sense. Variation is only one part of natural selection. Variation is random. The variation must also be inheritable, though, and that is a result of whether or not the variation is advantageuous in conjunction with the environment. So, in a sense, the environment does drive evolution. Of course, one could argue that the environment at any one point in time is random, but it is really a result of outside physical forces acting on the earth....which all boils down to the laws of the univers (gravity, etc,etc, which may be random or may be purposefully selected by some supreme being?????). ------------------
But aren't the laws of the universe, well, laws? So, doesn't that mean that they aren't random, but in fact, very non-random?? (I know this isn't a word ) ------------------ Poopy!
29 Evidences for Macroevolution http://www.talkorigins.org/faqs/comdesc/ Transitional Vertebrate Fossils FAQ http://www.talkorigins.org/faqs/faq-transitional.html The Evolution of Improved Fitness http://www.talkorigins.org/faqs/fitness/ ------------------
I am still convinced that these discussions never changae or anything. ------------------ Take an object. Do something to it. Do something else to it. " " " " "
