Orton's Arm Posted January 12, 2007 Share Posted January 12, 2007 Suppose there's a trait out there for, say, height, which is 80% determined by parents' observable traits, and 20% determined by environment, random chance, or recessive genes. Under those circumstances, if two parents were 100 units above the average height, their children would, on average, be 80 units above the population's average. Suppose that being taller conferred a survival advantage or reproduction advantage of some sort. Darwinism tells us to expect the population to become progressively taller. But there are those on these boards who implied otherwise--that this drifting back towards the population's mean would over the long run cancel out whatever genetic incentives for height Darwinism would otherwise have provided. According to this view, only those traits which are 100% heritable are candidates for Darwinistic evolution. Moreover, Darwinistic pressure towards increasing levels of height is presumed to bring about far more harm than good, due to the assumed reduction in the level of genetic diversity. I'd point out that if the views in the above paragraph are adopted, Darwinism's scope of influence becomes very narrow indeed. Few if any traits are 100% heritable. If the basis for Darwinism is rejected, all we're left with is Creationism. Do we need to start taking Creationism seriously? Or should we start believing Darwinism can and does work even if a trait isn't 100% heritable? I'm a Christian, but I believe that the basis for Darwinism is sound. Consider that the chihuahua is descended from wolf ancestors! Given a steady source of genetic pressure, and enough generations, animals can and will experience large changes. These changes aren't limited to traits that are 100% heritable, but seem to include any trait that's largely influenced by genetics. Edit: correction. Link to comment Share on other sites More sharing options...
meazza Posted January 12, 2007 Share Posted January 12, 2007 I'm taking bets on over/under of how many pages this thread will total. Link to comment Share on other sites More sharing options...
/dev/null Posted January 12, 2007 Share Posted January 12, 2007 I'm taking bets on over/under of how many pages this thread will total. pick a number, eventually the number of pages will regress towards it and then probably exceed it Link to comment Share on other sites More sharing options...
VABills Posted January 12, 2007 Share Posted January 12, 2007 pick a number, eventually the number of pages will regress towards it and then probably exceed it 3.5 generations for any change. Link to comment Share on other sites More sharing options...
meazza Posted January 13, 2007 Share Posted January 13, 2007 pick a number, eventually the number of pages will regress towards it and then probably exceed it You pick the number. I'm the bookey remember Link to comment Share on other sites More sharing options...
/dev/null Posted January 13, 2007 Share Posted January 13, 2007 I'm the bookey Nobody asked so please don't tell Link to comment Share on other sites More sharing options...
slothrop Posted January 13, 2007 Share Posted January 13, 2007 Everything you ever need to know about Evolution: Evolutionary Theory Link to comment Share on other sites More sharing options...
Nanker Posted January 15, 2007 Share Posted January 15, 2007 It's clear to me now. Once I had it explained by a Teacher. Alright kids. It is now my job to teach you the theory of evolution. Ahhhhhhhh!!! Oh Boy! Now, I for one think that evolution is a bunch of BULL CRAP, but I've been told I have to teach it anyway. It was thought up by Charles Darwin and it goes something like this. In the beginning we were all fish, OK, swimmng around in the water. And then one day a couple of fish had a Retard-baby. And the Retard baby was different so it got to live. The Retard fish goes on to make more Retard-babies and then one day a Retard-baby fish crawled out of the ocean with its – mutant fish hands and it had butt sex with a squirrel or something and made this – Retard-Frog-Squirrel, and then that had a Retard-baby which was a Monkey-Fish-Frog. And then this Monkey-Fish-Frog had butt sex with that monkey, and that Monkey had a Mutant-Retard-baby that screwed another Monkey and that made YOU. So there you go. You're the retarded offspring of 5 monkeys having butt sex with a fish-squirrel. Congratulations. Ahhhhhhhh!!! I can't take it anymore! Ahhhhhhhh!!! Yep, you see. I knew that would happen. Thank you Mr. Garrison for clearing that up for us. Link to comment Share on other sites More sharing options...
slothrop Posted January 15, 2007 Share Posted January 15, 2007 It's clear to me now. Once I had it explained by a Teacher. Alright kids. It is now my job to teach you the theory of evolution. Ahhhhhhhh!!! Oh Boy! Now, I for one think that evolution is a bunch of BULL CRAP, but I've been told I have to teach it anyway. It was thought up by Charles Darwin and it goes something like this. In the beginning we were all fish, OK, swimmng around in the water. And then one day a couple of fish had a Retard-baby. And the Retard baby was different so it got to live. The Retard fish goes on to make more Retard-babies and then one day a Retard-baby fish crawled out of the ocean with its – mutant fish hands and it had butt sex with a squirrel or something and made this – Retard-Frog-Squirrel, and then that had a Retard-baby which was a Monkey-Fish-Frog. And then this Monkey-Fish-Frog had butt sex with that monkey, and that Monkey had a Mutant-Retard-baby that screwed another Monkey and that made YOU. So there you go. You're the retarded offspring of 5 monkeys having butt sex with a fish-squirrel. Congratulations. Ahhhhhhhh!!! I can't take it anymore! Ahhhhhhhh!!! Yep, you see. I knew that would happen. Thank you Mr. Garrison for clearing that up for us. See above post Link to comment Share on other sites More sharing options...
ieatcrayonz Posted January 16, 2007 Share Posted January 16, 2007 Suppose there's a trait out there for, say, height, which is 80% determined by parents' antler sizes, and 20% determined by environment, random chance, or recessive genes. Under those circumstances, if two parents were 100 units above the average height, their children would, on average, be 80 units above the population's average. I don't know diddly about Darwin but I can tell you if I had antlers, the last thing I'd worry about is what percentile my parents were in when it came to height. Holcomb, I'm not sure which, but you need to see a psychologist, psychiatrist, surgeon, mathematician or taxidermist. Link to comment Share on other sites More sharing options...
Ramius Posted January 17, 2007 Share Posted January 17, 2007 I am a strong believer in evolution, due to my extensive background in biology and the biological sciences. But the fact that someone like holcombs arm is still alive today and wasnt done away with by nature is enough to make me question that belief. Link to comment Share on other sites More sharing options...
ieatcrayonz Posted January 17, 2007 Share Posted January 17, 2007 I am a strong believer in evolution, due to my extensive background in biology and the biological sciences. But the fact that someone like holcombs arm is still alive today and wasnt done away with by nature is enough to make me question that belief. How big are your Mom's antlers and how big are you? He has given you an objective means by which to test his theory and yet you refuse. Link to comment Share on other sites More sharing options...
yall Posted January 17, 2007 Share Posted January 17, 2007 Suppose there's a trait out there for, say, height, which is 80% determined by parents' antler sizes, and 20% determined by environment, random chance, or recessive genes. Under those circumstances, if two parents were 100 units above the average height, their children would, on average, be 80 units above the population's average. Suppose that being taller conferred a survival advantage or reproduction advantage of some sort. Darwinism tells us to expect the population to become progressively taller. But there are those on these boards who implied otherwise--that this drifting back towards the population's mean would over the long run cancel out whatever genetic incentives for height Darwinism would otherwise have provided. According to this view, only those traits which are 100% heritable are candidates for Darwinistic evolution. Moreover, Darwinistic pressure towards increasing levels of height is presumed to bring about far more harm than good, due to the assumed reduction in the level of genetic diversity. I'd point out that if the views in the above paragraph are adopted, Darwinism's scope of influence becomes very narrow indeed. Few if any traits are 100% heritable. If the basis for Darwinism is rejected, all we're left with is Creationism. Do we need to start taking Creationism seriously? Or should we start believing Darwinism can and does work even if a trait isn't 100% heritable? I'm a Christian, but I believe that the basis for Darwinism is sound. Consider that the chihuahua is descended from wolf ancestors! Given a steady source of genetic pressure, and enough generations, animals can and will experience large changes. These changes aren't limited to traits that are 100% heritable, but seem to include any trait that's largely influenced by genetics. Are you trying to discuss the finer points of evolution, or merely use another thread to discuss regression? Link to comment Share on other sites More sharing options...
Orton's Arm Posted January 17, 2007 Author Share Posted January 17, 2007 Are you trying to discuss the finer points of evolution, or merely use another thread to discuss regression? I'm discussing the relationship between evolution and regression toward the mean. For example, tall parents tend to have children who are also tall; but not quite as tall (on average) as their parents. Does this mean evolutionary forces don't apply to height? I feel all traits are subject to evolutionary forces; including those traits which experience regression toward the mean. Others feel that if a trait experiences regression toward the mean, evolutionary forces don't apply to that particular trait. According to this way of thinking, if something in the environment made it so that tall people tended to have more children than short people, the population wouldn't get taller. Regression towad the mean would make it so that in the long run, the population's average height would stay more or less the same. Because just about all traits are subject to regression toward the mean, that line of thinking constitutes a rejection of Darwinism. Link to comment Share on other sites More sharing options...
Orton's Arm Posted January 17, 2007 Author Share Posted January 17, 2007 I am a strong believer in evolution, due to my extensive background in biology and the biological sciences. But the fact that someone like holcombs arm is still alive today and wasnt done away with by nature is enough to make me question that belief. Wow! Just this once Ramius chose to post a personal insult instead of an intelligent remark! That's so unexpected of you, Ramius, so unpredictable! Oh, oh, what's next? Please tell us you could have posted something intelligent, but whomever you're disagreeing with would have been too stupid to understand it! Link to comment Share on other sites More sharing options...
Ramius Posted January 17, 2007 Share Posted January 17, 2007 Suppose there's a trait out there for, say, height, which is 80% determined by parents' observable traits, and 20% determined by environment, random chance, or recessive genes. Under those circumstances, if two parents were 100 units above the average height, their children would, on average, be 80 units above the population's average. NO. Thats completely out and out wrong. Heritability does not indicate the degree to which a trait is genetic, it measures the proportion of the phenotypic variance that is the result of genetic factors. Take a genetics class before you consider posting any type of response. Link to comment Share on other sites More sharing options...
ieatcrayonz Posted January 17, 2007 Share Posted January 17, 2007 NO. Thats completely out and out wrong. Heritability does not indicate the degree to which a trait is genetic, it measures the proportion of the phenotypic variance that is the result of genetic factors. Take a genetics class before you consider posting any type of response. Look. Before you guys get off on a 35 page rant, will someone please explain to me how people get antlers? No one is even disputing that, but I have never seen one person with antlers. WTF? Link to comment Share on other sites More sharing options...
KD in CA Posted January 17, 2007 Share Posted January 17, 2007 Please God make it stop. It's almost enough to make me want to read Molson's posts. Link to comment Share on other sites More sharing options...
SilverNRed Posted January 17, 2007 Share Posted January 17, 2007 Please God make it stop. It's almost enough to make me want to read Molson's posts. No it isn't. Link to comment Share on other sites More sharing options...
Orton's Arm Posted January 17, 2007 Author Share Posted January 17, 2007 NO. Thats completely out and out wrong. Heritability does not indicate the degree to which a trait is genetic, it measures the proportion of the phenotypic variance that is the result of genetic factors. Take a genetics class before you consider posting any type of response. The phenotype is something observable, and involves not merely genes but genetic expression; as well as environmental influences. The genotype is the underlying genes themselves. Heritability (in the narrow sense) is the extent to which children's traits can be predicted by observing the traits of their parents. If parents 1.0 SDs taller than the mean tend to produce children 0.7 SDs above the mean, the narrow-sense heritability for height is 70%. Heritability in the broad sense is the extent to which children's traits are determined by genetics. The extent to which a trait is heritable in the broad sense can be estimated by studying identical twins. In our earlier discussion, some of those who disagreed with me implied that if a trait was less than 100% heritable (in the narrow sense), evolutionary forces wouldn't apply. This implication, if correct, would undermine the basis for Darwinism. Link to comment Share on other sites More sharing options...
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