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Thread: How chancy is evolution

  1. #1 How chancy is evolution 
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    As far as iv been taught, in meiosis chromatins and chromosomes sepparate randomly( whichever ones get caught on either spindle). Doesnt this put in an element of chance as to wheather or not a mutation is passed on to the next generation?


    just wondering
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  3. #2  
    Forum Cosmic Wizard spuriousmonkey's Avatar
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    It doesn't really matter if you think big.


    "Kill them all and let God sort them out."

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  4. #3  
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    Sorry do you mind explaining?
    just wondering
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  5. #4  
    Universal Mind John Galt's Avatar
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    It doesn't matter what happens to single individuals, but to entire populations. I think that was spurious's intent.
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  6. #5  
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    But for a population to be affected the mutation had to be started in an individual, say there is a mutation for a bird to have a greater wing span, it doesn't affect the population if it doesn't happen to go in the right gamete right?
    just wondering
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  7. #6  
    Forum Cosmic Wizard spuriousmonkey's Avatar
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    Doesn't matter. So many generations, so many individuals. And does it really matter if they get this particular mutation? There are so many other possible ones.
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  8. #7  
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    It is gene frequency that evolution works on. How many members of a population have a specific gene. Mutations accumulate in populations. Most mutations are neither particularly helpful, or particularly harmful, which means they are not weeded out over time.

    Imagine an organism that has a mutation that modifies an enzyme so that it degrades a poison found in a rare food plant. If that poison is not commonly ingested, that mutation is harmless, and not much use. However, half of all the descendents of that original organism will have that specific gene. That might be a big part of a population.

    Only if the situation changes, and that poisonous plant becomes more common, and is eaten more often, will the gene frequency change. Suddenly, all those individuals who have the mutation will have a selective advantage. Over time, that gene becomes much more frequent in that population.
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  9. #8  
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    i get the whole mutation becomes helpful later on thing. I suppose my main question was if we played it over again is it likely that species would have different adaptations then they do now to deal with problems in different ways.
    just wondering
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  10. #9  
    Universal Mind John Galt's Avatar
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    This matter is in dispute. Stephen Gould made much of the fact, in his opinion, that if the 'tape of life' were replayed a different set of 'winners' would emerge. In conrast, someone like Simon Conway Morris asserts that nature is constrained by a tendency to move towards efficient 'designs'. He expects intelligent alien life to be (apart from intelligent) bipedal, with dextrous appendages and sense organs concentrated in a 'head'.

    The truth is that we do not know.
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  11. #10  
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    Ophiolite

    True, we do not know.
    However, the evidence suggests that chance plays a big role.

    For example : why are humans bipedal with two arms? Why not centauroid?

    The answer can be seen in the fossil record. We evolved from lobe finned fishes, which developed into the fish with amphibian characteristics, Tiktaalik, with two anal and two pectoral fins. We know from observing other fish that this number is not necessary. There could well have been six fins in total. But there were not, due purely to chance.

    Tiktaalik led to Acanthostega, a four limbed amphibian, which evolved into four limbed reptiles, and eventually into a four limbed human (2 arms and 2 legs).

    There is absolutely no reason, apart from blind chance, why terrestrial vertebrates might not have been based on a six limbed design.
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  12. #11  
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    Quote Originally Posted by skeptic
    There is absolutely no reason, apart from blind chance, why terrestrial vertebrates might not have been based on a six limbed design.
    That is one view. The alternative view is held by individuals with pedigree, logical arguments and supportive evidence. I remain unconvinced by either argument.

    Was it blind chance that led to fish, ichthyosaurs and dolphins all developing a similar form? The question is rhetorical, the point -hopefully - clear.
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  13. #12  
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    Quote Originally Posted by spuriousmonkey
    It doesn't really matter if you think big.
    To expand on this, there are a lot of misconceptions about how randomness works. Some philosophers I've met are actually able to convince themselves, through logical argument, that winning the lottery is just as likely as losing, since every number has an equal probability of being drawn. ..... This is obviously not so (the part about the odds of winning being equal to the odds of losing) but people fool themselves.

    An sometimes less known rule of probability for laymen is what people in the insurance business call the "law of large numbers." This law states that, over a sufficiently large group of dice being rolled, each outcome will come up with exactly the same frequency. The larger the group, the more this statement approximates to being perfectly true. So, it is very very rare that a person can roll a million dice and get 250,000 one's. Very rare indeed. You don't get exactly 166,667 one's either, but you always get something within a few ten thousands of 166,667.

    This means that, in a system as large as the evolutionary process, even a very small difference in the likelihood of survival will still always make itself felt.
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  14. #13  
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    Quote Originally Posted by kojax
    Quote Originally Posted by spuriousmonkey
    It doesn't really matter if you think big.
    Some philosophers I've met are actually able to convince themselves, through logical argument, that winning the lottery is just as likely as losing,
    This reminded me of a friend who was raised in Kenya. He used to defend lion hunting on the basis that the lion had a 50:50 chance.
    "Either you hit him, or you miss him. That's fifty-fifty."
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  15. #14  
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    Quote Originally Posted by kojax
    Quote Originally Posted by spuriousmonkey
    It doesn't really matter if you think big.
    To expand on this, there are a lot of misconceptions about how randomness works. Some philosophers I've met are actually able to convince themselves, through logical argument, that winning the lottery is just as likely as losing, since every number has an equal probability of being drawn. ..... This is obviously not so (the part about the odds of winning being equal to the odds of losing) but people fool themselves.

    An sometimes less known rule of probability for laymen is what people in the insurance business call the "law of large numbers." This law states that, over a sufficiently large group of dice being rolled, each outcome will come up with exactly the same frequency. The larger the group, the more this statement approximates to being perfectly true. So, it is very very rare that a person can roll a million dice and get 250,000 one's. Very rare indeed. You don't get exactly 166,667 one's either, but you always get something within a few ten thousands of 166,667.

    This means that, in a system as large as the evolutionary process, even a very small difference in the likelihood of survival will still always make itself felt.
    All lotto numbers have an equal chance of losing or winning.
    "Kill them all and let God sort them out."

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  16. #15  
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    Ah yes, the topic rears it's ugly head.... my bad
    Dick, be Frank.

    Ambiguity Kills.
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  17. #16  
    Forum Cosmic Wizard spuriousmonkey's Avatar
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    it doesn't, but then again think big. Play the lottery for a few million years every week and there is actually a fair chance of hitting the jackpot.
    "Kill them all and let God sort them out."

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  18. #17  
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    I believe the odds of getting a jackpot winning lottery ticket are within an order of magnitude or two of finding the jaclpot winning lottery ticket in the gutter. Therefore I do not waste my money needlessly investing in a weekly ticket, but just keep my eye on the lookout for carelessly dropped tickets. The only downside to this is that I walk into a lot of lamp posts.
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  19. #18  
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    Quote Originally Posted by Ophiolite
    I believe the odds of getting a jackpot winning lottery ticket are within an order of magnitude or two of finding the jaclpot winning lottery ticket in the gutter. Therefore I do not waste my money needlessly investing in a weekly ticket, but just keep my eye on the lookout for carelessly dropped tickets. The only downside to this is that I walk into a lot of lamp posts.
    This also means you don't end up making negative expectation bets , though I suppose that depends on how one values bumps on the forehead and the risks involved in taking things from gutters versus the cost of a lottery ticket.
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  20. #19  
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    Spurious, you missed the point about payout odds. These are what keep the gambling industry afloat despite calculable probability.


    And since your talking big picture. How much money did you actually loose buying a lotto ticket every week for however many years, when you could have instead invested that money in something with better odds, like a diversified portfolio that approximates the stock market average.

    Or something more practical, like finding an unmet demand and starting a business, or learning a profitable skill, or purchasing a piece of property that you can lease/rent to others for profit. etc etc

    But then in an alternative POV, in the big picture of things; lottery profits usually go into social services. Which ironically profit those the most, who tend to spend the most on the lottery.

    on a side note(a side note to a side conversation, lol) It's just a pointless cycle in my opinion. redistributing wealth from bored, stupid and/or hopeful individuals, to the boring, stupid and/or hopeless;; and then on occasion, to one particular individual, for no reason whatsoever.
    Dick, be Frank.

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  21. #20  
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    Quote Originally Posted by marcusclayman
    on a side note(a side note to a side conversation, lol) It's just a pointless cycle in my opinion. redistributing wealth from bored, stupid and/or hopeful individuals, to the boring, stupid and/or hopeless;; and then on occasion, to one particular individual, for no reason whatsoever.
    Which makes it a glorious affirmation of the wonders of being human.
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  22. #21  
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    hahaha, buy my lotto tickets then, express your glorious humanity!!
    Dick, be Frank.

    Ambiguity Kills.
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  23. #22  
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    Just as a side note I was thinking given enough time the most efficient adaptation would show up even if you replayed evolution, it would just take a different amount of time (although competitor/predator would constantly change) to reach it. Does this sound right?
    just wondering
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  24. #23  
    Forum Radioactive Isotope skeptic's Avatar
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    Zendra

    Does not always work that way. For example ; What if the most efficient adaptation for a wild horse to evade predators is to grow an enormous set of wings and fly?

    It will not happen. Evolution does not work that way. Instead, the horse grows better legs and runs. Evolution does no work on the best anything. It is always a compromise, and often a lousy compromise. Which is why over 99% of all species that ever lived are now extinct.
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  25. #24  
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    ok fair enough, i did mention exception when related to predator/prey.
    I suppose i was thinking more along the lines of maximizing and minimizing different chemical intakes such as in plants.
    just wondering
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  26. #25  
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    Quote Originally Posted by skeptic
    Zendra

    Does not always work that way. For example ; What if the most efficient adaptation for a wild horse to evade predators is to grow an enormous set of wings and fly?

    It will not happen. Evolution does not work that way. Instead, the horse grows better legs and runs. Evolution does no work on the best anything. It is always a compromise, and often a lousy compromise. Which is why over 99% of all species that ever lived are now extinct.
    That's because evolution takes everything into account, not just escaping predators. Those wings serve no useful purpose the rest of the time. They might help foraging for food, but they consume too many calories to give them a favorable calories spent vs. calories gained ratio.

    The best ratio comes from using legs instead.

    Quote Originally Posted by spuriousmonkey

    All lotto numbers have an equal chance of losing or winning.
    That's the half of the argument that is true. Only the the second half of the argument was false (the part about the odds of winning being equal to the odds of losing.) My philosopher friends often confuse themselves by pairing true arguments with false ones, and then trying to evaluate the whole statement as being fully true or fully false. I still hang out with them, though, because they're just so much more laid back than the people in the physics department.

    The lottery is set up just like the horse's wings: to give an unfavorable dollars spent vs. dollars gained ratio over time.
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  27. #26  
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    Quote Originally Posted by marcusclayman
    Spurious, you missed the point about payout odds. These are what keep the gambling industry afloat despite calculable probability.
    we are talking about evolution, so you missed the point in my opinion.
    "Kill them all and let God sort them out."

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  28. #27  
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    Quote Originally Posted by kojax
    That's because evolution takes everything into account, not just escaping predators.
    Quite the opposite. Evolution takes nothing into account. Hence genetic diseases and a shed load of DNA in most genomes that does nothing in particular.

    It's like water running down a hillside, it 'wants' to go in every possible direction, but various external influences cause it to move downwards (gravity) and then to form discrete channels (rocks etc) before eventually forming larger and larger flowing structures with blind alleys, waterfalls, pooling and rapids. The river was never an intention, it is not a planned outcome nor even an option chosen from a list of possibilities. Nothing was accounted for. It is all a consequence of the interaction of a body of water with gravity and a hillside.

    The products of evolution are basically the same deal.
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  29. #28  
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    Evolution has no intention but living entities all have intention and that is to survive. No goals, no directors, mindless process of random mutations, cause and reaction, body plans built imperfect, poorly designed critters, no natural laws, chaotic animated atoms is all life is right?

    From single cells to multi-celled organisms to body plan organisms all have one thing in common and that is to survive. For a non thinking process that randomly put in alot of effort to make sure that the replication and reproduction process was successful for 3 1/2 billion years for the sole purpose to recycle energy to keep life going for as long as this planet is able to support it is not dumb luck.

    I heard some people say that bacteria are not aware that they are alive or aware of death. Are you aware that you are alive and do you fear death? of course!

    We are made of bacterial cells but we prefer to call it a eukaryotic cell. In reality we are a bacterial human species that is a host to colonies of different species of bacteria that enable us to stay alive. This entire planet that is considered living are all bacterial but come in all different sizes, shapes, body styles, etc.
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  30. #29  
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    mindless process of random mutations, cause and reaction, body plans built imperfect, poorly designed critters
    Well actually natural selection keeps those mutations that help make the critters more perfectly suited to survive in their environment


    randomly put in alot of effort to make sure that the replication and reproduction process was successful for 3 1/2 billion years for the sole purpose to recycle energy to keep life going for as long as this planet is able to support it is not dumb luck.
    No your right its not dumb luck, those that put in a lot of effort were rewarded with surviving.

    I heard some people say that bacteria are not aware that they are alive or aware of death. Are you aware that you are alive and do you fear death? of course!
    Are you saying bacteria are just as smart as us? Do they have a brain?



    I hope your not trolling because as i finish this I feel like I'v bitten the hook.
    just wondering
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