*cough*... right... uh... *stupid look* since the math, as well as the physics stuff (gravitational gradient vs. gravitational pull, stuff like that) totally went over my head (I hate math), I figured I'd search. wikipedia: tide So ... you tell me. Does that mean that the gravitational PULL is greater fromt he moon? or the gradient or whatever?
The AlphaWolf: The classical gravitational formulae are very simple and I trust my memory on this issue. Twice the mass at the same distance, results in twice the force. Three times the mass at the same distance, three times the force. The force depends directly on the mass. Twice the distance, one quarter the force. Three times the distance, one ninth the force. The force depends inversely on the square of the distance. The gravitational force computations in my last post are correct unless I made a mistake in either the data or the arithmetic, which I doubt. If you know somebody who can do these calculations, ask him to check my data and my arithmetic. I am aware that the tidal force due to Luna is greater than the tidal force due to Sol, but I am certain that this does not imply that Luna has a greater pull on Earth than Sol. I do not know the formulae for tidal effects, so I cannot be certain that my calculation of relative tidal forces for Luna and Sol are correct.
Well Dinosaur its to bad you resort to insult phrases, to communicate. I guess in your opinon it was nessacary to make insult comentary to up lift your mental frame. So then in your grand proffesssion of facts which is it that is reponsible for the proccess of aging, is it the SUN, MOON, or just wind. May be it is a plot, where by chemical are placed in foods to cause aging, or is it a lack of education about how to eating food. I will Remember that Dinosaur said that my concepts about the effects of or solar system on human life was worth less nonsenses. But please exsplain again for us the aging proccess. DwayneD.L.Rabon
I never said an aging mutation is favored in natural selection as you CONSTANTLY accuse me of. I pointed out that it would have gotten into the gene pool anyways because its negative effect (dying) was negligible during early stages of lifeform's life. I wont say any furthur. All in all, I think this is pathetic. You still cant grasp the point I was making to you. Twist your ideas around. Claim you claimed something else. Misinterpret my words. Arguing on the internet is seriously pathetic. And your quote-reply style of writing is frankly very annoying too. Im not going to put up another rebuttal.
I think everyone should just walk away from this thread. Nobody has demonstrated any real knowledge of the biology of aging. Everyone is arguing and getting all hung up on little tidbits of knowledge and isolated factoids. The thread is now so disjointed that it’s not worth the effort to go back and correct the numerous fallacies that have been put forward by numerous people. Just walk away – it will be good for the blood pressure. Please Register or Log in to view the hidden image! <P>
I tend to agree, but will note that the sun's gravitational force on moon is stronger than Earth's but the Earth's gradient at moon (or the moon's at Earth) is stronger than the sun's because the gradient falls off as the cube of the separation but the force only as the sqaure. alphawolf is correct in that evolution does not look ahead, but wrong in that natural selection (which really acts more on the gene pool than the individual) can not select for aging and death, if gene pools with these characteristic are more "fit" (and they are because these characteristics can get the old deadwood out of the way so the resources are available for the new models.) Recall the analogy I made with old cars. There comes a time, even without built in aging, that the wear and tear on bodies makes it not worth while to repare them, just as with cars. - I.e. it is better to get a brand new edition, make from digital information, (genes) than to continue to repair the old issue from the womb factory.
Ok, I figure I can understand what you say better than SS, so I'll ask you to explain. First, how does natural selection act more on the gene pool than the invididual? Natural selection acts on the gene pool THROUGH the invidividual. I agree evolution only works on populations and not on indivudials, but natural selection itself only works directly with individuals. And I still don't get how aging would be selected FOR. Your basic premise appears to be that the organisms that do not age won't get replaced, which isn't the case as they would still have offspring, which would have the immortality genes, which would replace the other "immortal" organism. Just like trees and stuff. Many trees don't age, yet obviously trees HAVE evolved, and ARE fit. I don't see how gene pools with the aging genes would be more "fit". The problem I have with that analogy is that cars don't reproduce. You're assuming that "immortal" organisms wouldn't have offspring to replace them. Evolution wouldn't replace the IMMORTAL genes, it would replace the worn out INDIVIDUALS. (no need to "repare" anything). Basically what I'm saying is that aging is not selected FOR, but it did evolve. It's just a side-effect of evolution.
I do not think we differ enough here to discuss much more. I was only trying to say that the individual's genes are in the gene pool after a few generations, if he had offsprings; and that selection would rarely if ever effect the number of offsprings the first with the new mutation had. That is, "good gene A" in the gene pool helps many individuals carrying it during the next few thousands of years. This subgroup grows relative to those in the population without "good gene A." Some of the individual carriers of "good gene A" still got eaten by tigers etc. The success of "good gene A" is more a matter of its effect on the gene pool than on any individual.* Not my premise. Not my assumption. Certainly there are "neutral characterists" that just happened,which one could call "side-effect of evolution," but programed death of cells surely is not a "neutral characterists" - Ergo, It was selected for. One can not be sure of the mechanism of this selection, but I bet it was that if individuals do not becomes less fit and die, then duirng the thousands of years they live, they will have non fatal accidents (leg crushed by falling tree etc.) Thus an injured population with average age of 10,000 years is not as fit in the stuggle for survival against a competing population made up of uninjured people with average age of 30 years. This may not be the correct reason why most creatures, including man, age but it seems to me to be a possible one. The point is not whether or not I have guessed the correct reason, but that some reason does exist. -I.e. aging did not just "happen" to creep into all animal gene pools but was selected for. This also illustrates why it is important to understand that although the selective advantage is for each individual with "good gene A" it is the survival benefits that "good gene A" gives to the gene pool / population that is most important. _______________________________ * A good example of a gene that is bad for the individuals carring it but good for the population is gestation term. Longer gestation causes more women carrying genes for this to die in child birth but is good for the population. Obviously, some compromise is reached, but looked at only from the individual mother's point of view, more smaller babies would rarely be fatal for her. If only the individual were important, then human gestation peroid would be less than the 9 months as even with modern medicine this still kills some individuals. (I assume you will agree that carrying genes that sometimes kill is about as negative a selection FOR THE INDIVIDUAL carrying them as you can imagine.)
Aging isn't as simple as just programmed cell death. There's more to it (genetically speaking, I know free radicals and stuff don't count).... but yeah... I agree. How is that selecting FOR aging? That's more of what I was saying... since the "immortal" organisms are still becoming weaker and stuff, they reproduce less, and therefore mutations that age individuals aren't relevant in the long-run. That's what I'd consider side-effect, as natural selection isn't favoring aging, aging just happened to evolve because other things are more important than living longer. Evolution isn't selecting aging, it's selecting other things and the side effect of those other things is aging. lol, you make it sound funny. Aging creeping into gene pools Please Register or Log in to view the hidden image! I think the issue here is just semantics. We're both talking about the same thing, except you call it selecting for aging and I call it a side-effect.
Strange that the same "side effect" should creep into all animal gene pools - I admit you can call it bopa or anything you like, but "side effect" implies that it just happened to be beneficial and it being beneficial had nothing to do with it becoming part of all animal's gene pools. With this approach you can get rid of all of Darwin's ideas. The natural selection process had nothing to do with evolution - it was all only side effects. Perhaps I missunderstand you. Please tell me what was the "main effect" being selected for that is always accompanied by the aging "side effect"?
It is possible or likely that aging is merely due to an inability to continue repairing a complex organism? Perhaps complex organisms die in 120 years or less due to there being no evolutionary pressure to select for immortality, rather than there being pressure to select against it. Continuous repair of an organism as complex as a human being seems like a formidable task. As posted elsewhere in this thread, there is some evidence that evolution can select for longer life if it enhances reproductive success. In my memory, the most complex organisms which come close to immortality are various plants: Bristle Cone Pine trees, some other types of trees, and some fungi. Otherwise, I think that only single celled organisms are immortal or close to it. Compared to humans and other animals, the extremely long lived organisms are relatively simple. I think that Bristle Cone Pine trees produce viable seeds after living 2-3 thousands years, making longevity reproductively successful for them.
Yes it is possibel, but no to the non-selection idea, because there are aging clocks in each cell. Not sure of spelling but they are called the "telemars" - basically a string of molecules that gets shorter each time the cell divides to make its replacments etc. Interestingly there was a lady, who in the literature is called "Helen B" that did have some cancer at Johns Hopkin. Some of her cancer cells did not have the tellmars (or something else that caused then not to grow shorter). Helen B cells have been a problem for the bio-research industry which often exchanges tissue smples and cultivates cells. I.e. Helen B cells have spread thru out the world and do not die off after replicating. Many cell cultures are now contaminated with Helen B cells. To build the normal complex programed cell death cycle (telemars) in to all cells (with Helen B's cancer cells being a possible defective mutation) requires evolutionary selection for aging. It is definitely not a "side effect." Defintiely not an acident. Definitely not what one would normally call "wear and tear." It is a complex genetic program that was selected for and makes gene pools with it more fit than those without it in mutual competion, for the reason you (and I) mentioned. I.e. accidents do happen (including accidents of improper cell repair and replacement) and after a few thousand years of life, most of the immortal organism population is not very fit, can not compete for survival against a gene pool, housed in bodies that were recently produced from digital information (genes) and is still nearly perfect.
First off... I started thinking... why is aging beneficial? HOW is it beneficial? Ok, it replaces the old by the new. That still happens in organisms that don't age. Maybe it happens faster? EDIT: about cancer... cancer also needs other mutations in order to be cancer. Having telomerase to keep adding the telomeres isn't enough for it to be cancer. They need to reproduce faster, have a mutation that makes them NOT stop reproducing when it gets too crowded, etc. but anyway, assuming it is beneficial, that's pretty much what I'm saying. It didn't evolve for being "beneficial". huh? why? it makes perfect sense using darwin's ideas. I'm just saying that not EVERYTHING evolved because it was selected FOR, some things just evolved as concequences of something else. That's it really. I doubt you can disagree with that statement. Aging is one of those. and by selecting for I mean that aging individuals didn't have an advantage over immortal individuals. That natural selection didn't say "ah, you age, therefore your genes will be passed on. You don't age, so your genes will die". And that's the only way natural selection works- by WEEDING OUT the "unfit" individuals. Immortality would NOT be weeded out. It's not a disadvantage. Aging was not selected AGAINST, and therefore survived, but it wasn't selected FOR either. it's basically exactly like useless vestigial organs. That's how they wither away and become functionless. What happens to something that doesn't affect your ability to pass on your genes is irrelevant. I dunno, it may have been that a good mutation causes harmful effects later on, or organisms had bad mutations that happened later in life and therefore there wasn't a selective pressure <i> against</I> them, etc. Telomeres. It's part just of the DNA at the end of chromosomes, and because of certain uh... not errors... um... because of something that goes on during replication, the genome gets smaller every time. Therefore telomeres are a kind of buffer preventing real genes to get shorter (and therefore be rendered useless) every time replication takes place. This is How I think they evolved: most eukaryotes with distinct (non-circular)chromosomes have telomeres. Organisms like yeast or simple organisms that don't age obviously need to keep regenerating the telomeres every so often, or they WOULD age, so they have an enzyme called telomerase that does just that. Humans also have telomerase, but it is only active in gamete production (for obvious reasons) and early embryo development/stem cells such as bone marrow cells and others. Now, what I'm thinking is that at first organisms had telomerese active in all cells, therefore rendering them "immortal". It was part of their genetic code. Then, because older organisms did not have as many offspring as younger ones, mutations that stopped telomerase from being produced later in life remained in the gene pool. Fast forward, and you have telomeres long enough so that organisms can reproduce, but short enough and without telomerase that organisms age. again, it was not selected FOR, they didn't have an advantage over others, it just happened that way.
Not much point to continue this. You remain focused on individuals, immediate benefit, speak of evolution "for being benefit" (not random and then selected etc.) but I will try again Nothing evolves for benefit. Mutations occur, most are quickly selected against in the first indvidual to carry them (often prior to birth), some are neutral but probably lost in a few thousand years, a very few provide small benefits, but usually insignificant to any individual. (lost in the noise of all the other things and events that determine his fate and reproductive rate). It is the cumulative small effects over thousands of years in the gene pool (that "pull" the weak signal out of the noise) in the typical case where the small benefit is finally detectable as slight increase in the preveliance of the new gene in the gene pool. In another 50,000 years most may carry the new gene. Repeat this millions of times and you can evolve eyes etc. I.e. the first individual multi-cell creature to develop a few light sensitive cells got essential no benefit from them, but they were nearly neutral and the basis for the next step etc. Evolution almost always works much more on the gene pool than the individual. The sudden functional improvement (the "hopeful monster") that could be notice in the noise of daily events is extemely rare if it ever happened at all. I disagree. Genetic mechaism for aging is too common in almost all mutli cellular life forms to be an accident. It was selected for. I have already explained why a gene pool housed in "imortal bodies," which in 10 or 20 thousand year of living would on the average be severly crippled, perhaps fingerless, blind etc. from accidents. I.e very unfit in competion with a set of genes housed in recently created bodies, which were made from digital instructions (genes) and still nearly perfect. Your "imortal individuals" would be strongly selected against, probably starving to death (or more likely eaten by the physically-fit young ones, blessed with the aging gene) if food was short. Perhaps considering which won the competion for audio recording technology will help you understand what I have already explained before. The vinal recording LP suffered accidents (scratches etc) but the digital CD is not so damaged during it a much longer life. Which is more fit after 1,000 uses? The gene pool that can eliminate the accumulation of accidental damage is more fit in the long run. PS do not try to turn the argument around by claiming that the audio CD is the "imortal one" - With iPods, downloading into gigabite drives etc, it is already on its way out with less than half the life span enjoyed by the good old vinal LP.
