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Aware of evolution

  1. Aug 23, 2010 #1
    Is having a genetic advantage enough for evolution to occur? Doesnt a organism require some sort of knowledge (or instinct) in order to use such an advantage in order for it to be any sort of advantage? Example: we say the first step in the formation of a eye is a cell that is sensitive to light. Well wouldnt the organism with this advantage have to be aware of it in order to use it. It cannot be taught how to use it as there wouldnt be no any one to teach it. Without and knowledge or instinct of how to use this new trait, this organism would have no advantage at all. A organism with the ability to sense light means nothing if it does not know how to apply it. If you don't know how to use it you lose it.
     
  2. jcsd
  3. Aug 23, 2010 #2
    Ok might be off a bit here but please correct me if am. What u describe as knowledge or instinct probably dosnt exsist at all. Animals and man to a large degree are self aware not because we are programed but because our minds are emergent. The senses send raw data to the brain. The brain self organises through trial and error. Connections that produce positive results are reinforced while those that produce negitive results are broken. Thus all organisms that survive to open their eyes taught themselves to use them. The brain is not only plastic after being damaged, it is plastic in self organization. In general there may be a few things that are genitic like hate those who dont look like me or fear others that are bigger than me but even these small geneticly programmed sences are highly variable between individuals and might have a nongenitic explantion.
     
  4. Aug 23, 2010 #3
    in my opinion its a question involving the driving force of adaptation...or one of them.



    mutation



    thats the missing variable you are looking for. animals evolve because of mutations and without them adaptation would stop as the latest science would say.

    The mutations are either helpful, nonhelpful (like skin tags, a dermatological imperfection but not a huge deal) or deleterious (lethal) for example.

    in the case you mentioned, my prof always said the are fish with and without eyes. whether or not you have them is because some benefit was conferred to you upon the mutation (or creation) of phototically-sensitive cells. they provided conduction of some form of beneficial energy such that new pathways are created or sustained that lends adaptability to the organism as a whole, otherwise they are just a waste of energy and will rescind (snake legs)


    he didn't say it like that but pretty close. that was 96 forgive the years.
     
    Last edited: Aug 23, 2010
  5. Aug 23, 2010 #4
    The answer is No, but not in the way you intended. For the genetic advantage to lead to evolution the following conditions must also be met:
    1. The environment in which the organism lives must remain such that the genetic advantage remains an advantage.
    2. The organism must not contain sufficient genetic disadvantages to lead to, on average, a net disadvantage.
    3. Chance must favour the reproduction of the organism.

    Do you need to know how to use a thicker fur coat to benefit from improved resistance to cold temperature? Do you need to know how to use a sharper tooth to more effectively kill your prey? Do you need to know how to operate your immuned system to better resist disease.

    I hope you see that the answer to each of these is a resounding No.

    Most prganisms are not aware in the sense I think you mean it. Most organisms are single celled automata. Most animals that are aware make use of nearly all their genetic benefits without conscious thought. This includes humans. You don't need to know that you have more fast twitch muscles in order to run. You just learn to run like everyone else then discover you are damn fast. The Olympic medal follows on.

    Simply untrue. I don't know how to make insulin, but my body seems untroubled by this and gaily goes about making insulin in response to biochemical promptings.
     
  6. Aug 24, 2010 #5
    that's not an exact correlation. Insulin production is involuntary, whereas the 'use it or lose it' question concerns voluntary processes that involve choice.
     
  7. Aug 24, 2010 #6
    The insulin production is part of a programed involuntary response system. Things like, running, which involve voluntary control, need to be chosen in order to engage the ability of the body and, if activity requiring the use of certain bodily abilities is not chosen often enough, the ability to perform the activity could be lost.
     
  8. Aug 24, 2010 #7
    This thread sounds like a variation of the mousetrap argument.

    Edit: here is a particularly http://udel.edu/~mcdonald/mousetrap.html" [Broken].
     
    Last edited by a moderator: May 4, 2017
  9. Aug 24, 2010 #8
    binbots calimed in his OP that an organism had to learn to use a genetic advantage. I demonstrated that this was not so, and thus his argument is false.
     
  10. Aug 30, 2010 #9
    LOL, no I was not trying to start up the mouse trap argument. These arguements seem to be about much more complicated organisms than I am speaking about. Saying how the brain works etc is not what I am trying to get at. I am taling about very primitive organism. i am also not taking about mutaions in which you dont need to be aware of in order to use. I am saying that thre must be SOME mutations in which a certain amount of awarness is required. As with the example I used before. How can a primitive organism be able to use his new super sensitve to light cell as a advantage if it has no idea what it is it is seeing? Sorry for sounding repeatative, but I guess it is my fault for not being specific enough.
     
  11. Aug 30, 2010 #10
    Sorry if it was a bit wordy. I meerly ment to say that the awareness you were speaking of is caused by the "eye" being there in the first place. A trillobite (example only) who developed a "better eye" might not know what to do with the improved vison it has but might learn to make simple associations, green plants GOOD brown plants YUCKY. By having this "better eye" its decendents would also quickly learn to make the same association. And so it gets passed on, not because they inherited the instinct but because enough of them could make the connection.

    Lemme put it this way.
    A. New eye is useful, confers an advantage and lineage expands.
    b. New eye has undiscovered uses, no advantage so the mutated gene degrades(like our vitamin C gene has)
    C. New eye is biologicaly expensive and not very useful, lineage dies out quickly.
     
  12. Aug 30, 2010 #11
    Maybe it can't. A fully formed eye would be useless if it wasn't connected into the nervous system, and the corresponding genes would simply go extinct.

    But that's an unimaginative pathway. Consider if a mutation makes some nerve ends slightly sensitive to light (as well as touch). This would confer the organism an immediate advantage, that it can detect objects and predators/prey by their shadows as they approach, a few moments before physical contact is made, and so it has the advantage of more time to react. Even if this organism doesn't "know" that it really is reacting to the shadow (and instead "thinks" it is reacting to things brushing against it). And since this may be advantageous, it would be more advantageous still for some of the nerve endings to be even more strongly light-sensitive, for these light sensors to be concentrated around the head rather than interfering with touch sensation all over, to be arranged for incrementally better directional resolution.. little by little, the development of an eye can be advantageous at every stage.

    Note also how the brain works: it readily adapts to new sensory input. For example, you can create devices that transfer compass readings onto your skin, and within a few weeks your brain will rewire this input so that instead of being aware of a skin-sensation you are simply always unconsciously better aware of which way things are. There does not need to be any change in the design of the brain, it will automatically rewire itself. No reason you should need to know what a sensation means before you start to learn how to use it.

    Of course, I don't know what the actual historical evolutionary pathways were for your example, and I don't know how what or how many intermediate stages were involved (note mutation is discrete rather than continuous).
     
  13. Aug 31, 2010 #12

    bobze

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    2 quick points,

    1. I think you're thinking of mutations the wrong way. It's hard not to think of mutations as conferring a "noticeable" (to humans anyway) advantage when they happen, even to the biologically inclined. That's just the way our brain wants to view things.

    In reality, mutations might be extremely small, tiny little changes with little selective value that only "shine", on down the line when other mutations happen.

    2. I don't think you're going back far enough with your example, remember that biology has a chemical basis. Eyes didn't come first, nor did simple eye patches, nor even a few "eye cells". Eye spots came first, which let organisms (through biochemical reactions coupled the cell's cytoskeleton) discern where light was vs where it wasn't.

    Build upon that system, step wise and slowly (and don't forget to add multicellularlity, then germ layers, then nervous systems etc) and I don't think "requirement to use eyes" is a problem anymore.
     
  14. Sep 1, 2010 #13
    Okay, I shall succumb to the temptation to reply to this thread. The notion expressed in binbots’ original post (OP is original post, right?) is entirely spurious. There has never been any suggestion whatever that for a selective advantage to be operative, the species itself has to be aware of its existence. One example that springs to my mind is zebra stripes. They are a good example because, to this day, though there are several hypotheses, there is absolutely no certainty whatever about exactly what selective advantage the stripes confer. All that can be said is that, for the feature to have become fixed in the species, they must have offered some selective advantage. What is widely accepted is that, whatever selective advantage they do offer, it is a tiny advantage. Thus zebra stripes are a good demonstration of the point that only a tiny selective advantage is necessary for a feature to become fixed in a species. What is also absolutely certain is that, whatever the advantage conferred by the stripes may be, the zebra themselves are utterly unaware of it. If it be that the stripes are better at causing confusion among lions when chasing an ever moving herd, then it just happened that stripy zebra had less tendency to be caught by the lions than did non-stripy ones. Whatever the truth about the advantage conferred by the stripes, the zebra themselves just led their lives, and the stripy ones made a better job of surviving and reproducing than did the non-stripy ones.
     
  15. Sep 1, 2010 #14
    To me there has always been something missing from the evolution theory. A driving force that pushes a species in a certain direction. Random mutations and natural selection don’t seem enough, another force is at play here. We say that evolution takes tiny, tiny steps and these lead to advantages. Well the smaller we make these steps the smaller the advantage, the harder for this advantage to spread throughout a population. The bigger the step the easier it will spread through a population but the harder it is to explain how this huge step came about genetically. Do you see the problem here?
    So what is this other driving force? Well the answer is so simple that it seems we have over looked it. It seems we never factor it in to the equation. It is us. We have been deciding our own evolution for a very long time. We decide who we breed with. We decide how tall, small, fat, smart etc. We are going to be. Every time we select a breeding partner we are putting in our vote for the next generation on evolution. To say we have no control is a very primitive view and may work well for certain primitive species. But for any species which has a CHOICE as to who to breed with has control. This is not NATURAL selection. This is selective breeding. We have been selective breeding certain species for thousands of years. This whole time we have been doing to ourselves as well, just unaware of it.
    Once we start looking as evolution as something we control a lot of things become a lot simpler. Example: For some reason our brains stayed approximately the same size as a chimps for millions of years. Then for some strange reason our brains started to grow at a rapid pace. It is still kind of a mystery as to why this happened. Explaining this with just the random mutation and natural selection is very hard to do. The answer they came up with was that there was constant climate change at this time which forced us to become smarter. I am not a fan of this answer, once again it is to random for me. An easier way is using selective breeding.
    A man was born in a tribe with a larger brain, hence he was smarter. This man figured out a new affective way to hunt. This man became revered and may have even become the leader of the tribe. This man had many offspring because of his new statues. From this moment on humans became AWARE that intelligence was a trait which we liked and they could help us survive. From this point on smart people were moved to the front of the breeding line. This is where the human brain started to grow rapidly. While our other traits like strength declined. WE decided what trait we wanted. There may have been men with this same larger brain mutation before. But until we decided a bigger brain is what we wanted these men just blended in like the rest of them.
    So why don’t we ever talk about our own power of evolution. The evidence is all around us. Birds pick birds with the brightest colours, they get brighter and brighter. Elephants pick large mating partners and they get larger. If anything this is the main component to evolution, and would explain so much mystery. Are we afraid to admit how much control we have?
     
  16. Sep 1, 2010 #15
    Yes, I see very precisely the problem here: Your understanding of evolution.

    Quite wrong. Population mathematics show that a selective advantage can spread throughout a species very quickly, certainly in evolutionary terms. The slow part of evolution is waiting for the advantageous mutations to come along. Once they appear, they become fixed in the species quite rapidly.

    You are quite correct that ‘survival of the fittest’ is not the only selective mechanism. The one you describe is known as sexual selection and has a large influence on many species – birds of paradise being an obvious and extreme example. There is also a phenomenon known as ‘genetic drift’. One of the best examples I have come across of this is in snails. These days, snails are nearly all ‘right coilers’. Once was the time when there were pretty equal numbers of right coilers and left coilers. Being a right coiler or a left coiler offered no particular selective advantage, until genetic drift led to the dominance of right coilers. Now, since opposite coilers find it harder to mate than same coilers, being a right coiler had a selective advantage. So right coiling became the norm.

    Incidentally, there’s an extra real fascinator to this story: The gene that controls left coiling or right coiling in snails is exactly the same gene that controls human left / right asymmetry too! Most human beings have the same layout of internal organs. But mutations to that gene do mean that just occasionally, human beings are born with all their organs opposite hand. Other mutations to that gene can cause a more disorganised arrangement, but this is immediately fatal to the developing embryo.

    And as for selective breeding, yes man has intervened in animal (and plant) breeding for thousands of years, but the notion of its effect on the resulting evolution of those species is nothing new. The opening chapter of On the Origin of Species is a lengthy consideration of domesticated breeds of pigeon and what they tell us about the mutability of species.
     
  17. Sep 7, 2010 #16
    So sexual selection does show that we control our evolution. The point I am trying to make is that one of the first things we learn about evoltion is how random it is. But it seems that statement is very wrong.
     
  18. Sep 7, 2010 #17

    bobze

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    That's not one of the first things you learn about evolution, I think that is a misunderstanding people have of evolution that gets propagated over and over again.

    Evolution's main driving force is selection (natural or sexual), NS requires 4 postulates;

    1. Variation between individuals
    2. Heredity (some variation is passed on)
    3. Limited resource to cause competition and extinction of forms
    4. Differential survival and reproduction

    Ergo, it is not driven by "randomness", rather by the non-random survival and mating of variant forms.

    You could even make an argument that mutations (the "random" aspect of evolution) is not random. Certain parts of the genome are more mutation prone than others and certain changes result, more frequently in mutations (like deanimated cytosine results in few mutations, while deanimated 5'-methyl-cytosine results in lots mutations).

    If evolution was random (or in other words all individuals in a population were equally likely to survive and mate) then adaptive evolution could never have happened and life would be stuck back at LUCA
     
    Last edited: Sep 8, 2010
  19. Sep 8, 2010 #18
    Your first assertion draws a very definite response. Sexual selection does not show that we control evolution. Sexual selection operates perfectly naturally in many species without the influence of humanity. When a male elephant seal controls his harem by fighting off all his rival bulls – that’s sexual selection. When a male lion defeats the sitting male of a pride, kills all the defeated male’s cubs and then sets about fertilising the females himself – that’s sexual selection. And the outlandish, sometimes outrageous features that male birds of paradise develop, driven entirely by very choosy female birds of paradise – well that’s sexual selection too.

    Yes, humankind has intervened in the breeding of plants and animals for thousands of years. But one of the key points to grasp about evolution is the vast time periods over which it operates. It has literally taken us billions of years to get to this point. Humanity’s effects on evolution remain the tiniest of drops in the most vast of oceans.

    Your second assertion essentially draws agreement. But I’m not entirely certain you grasp why. You are right, the whole process of evolution is not so random as many people seem to think. Firstly, as bobze has pointed out, the natural selective part of evolution is not at all random, and it is entirely that part that tailors species to their environment. The ‘random’ part is the mutations that drive species change. Even that is not just as random as you might think. Just as lottery numbers are only random between very definite limits, so there are very strict limits on the random nature of species mutation. The random bit is actually only in the sequence of bases in the DNA, and there are only four of those. They code for amino acids in groups of three, but there are actually only twenty different amino acids, and there are even different sequences of bases that actually code for the same amino acid. The amino acids build up into proteins, of which there are a very large number, but not a limitless number. And those proteins have their effect on the final organism by affecting the embryonic developmental sequence. So you can see, this notion of ‘random mutation’ can be very misleading. A lion cannot suddenly sprout wings. A snake cannot suddenly grow legs. A mouse cannot suddenly develop the power of speech. All any species can do is make tiny adaptations to what it already has. And there are any number of examples of species that put a feature originally developed for a very different purpose to very novel use. Whale hind legs, for example.
     
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