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Random evolution

  1. Mar 22, 2010 #1
    How can we say that evolution is random when it is based on choice aswell? For example the first creatures that came onto land made a choice to do so. Sure they were probably pushed there to survive but they still made the choice. Throught out evolution these decisions were made and evolution then followed to fit the choice. When you start looking at evolution this way you will start to realise how much control we actually have over our own evolution. Am I wrong?
     
  2. jcsd
  3. Mar 22, 2010 #2
    That's where I stopped reading.
     
  4. Mar 22, 2010 #3
    wow, really. Good to see you never question anything you have ever learned.
     
  5. Mar 22, 2010 #4
    Fixed. It's good to see you questioning things prior to understanding them though.
     
  6. Mar 22, 2010 #5
    Your argument hinges upon the fact that early organisms had the capabilities of rational, ethic and philosophic decisions. When in fact most of them were driven by simple stimuli that either enhanced or weakened their chances of survival.
     
  7. Mar 22, 2010 #6
    Yes. You are wrong, but your mistake is a common one: evolution is NOT random. There are many factors which allow for changes in any organism's inheritable characteristics. Some of them are quite random: eg, the specific location where a cosmic ray might damage its DNA.

    Other factors, such as the choices a creature makes in deciding if it should migrate today or in a month are not so random at all ... and the particular choice might have life or death consequences.

    I can recommend an excellent book: "Inside the Human Genome" by John Avise , a professor at Univ. of California , I believe.
     
  8. Mar 22, 2010 #7
    Sorry, I don't see how it is completly random when it can be controlled. If food is hard to come by where I am now, I will make the decision to move to wherever I want. Based on that decision over millions of years I will evolve based on my decision. To say early creatures did not have this ability to make choices is a huge assumption. I will decide where to raise offspring and they will evolve accordingly. The results may not be random but more of a probablity based on decision.
    Plus once we evolve we must be aware of our new state in order to use it. To know how it works and what we can do with it. To simply say evolution is random to me seems that nothing can be controlled. Which would make every decision you make pointless.
     
  9. Mar 23, 2010 #8
    Please just stop posting if your not going to read the responses. I left it up for you to find out what was wrong on your own, however someone has drawn it out for you completely.

    Why are you under this notion that evolution is completely random? Why do you think that evolutionary pressures are decided by organisms? How do these decisions effect the evolution of the organism would it have been different had they made a different decision??? All of these are possible to answer however, it doesn't change the fact that your original premise of evolution being random is wrong.
     
  10. Mar 23, 2010 #9
    Ok, I will stop posting. Thanks for your responses.
     
  11. Mar 23, 2010 #10
    It is interesting that your reply is as absurd as was your proposition that evolution is a 'random' process.

    That you would, given the option of actually reading our replies, you perfer to cease posting rather than to turn your brain on and actually LISTEN to what we've been telling you is remarkable.

    Why not let us know if we've successfully informed you of the 'laws' of evolution?? Or do you prefer that we, on that matter, remain as much in the dark as you profess to be in your comment?
     
  12. Mar 24, 2010 #11
    I mean I will not post anymore on the subject until I learn more. Sorry for the confusing. I am reading the responses.
     
  13. Mar 24, 2010 #12
    oh thanks for clarifying ... i do, then, retract my criticism , please forgive my misunderstanding. Good to see that you are interested enough to investigate the matter .. you're showing a quality which is highly valued in the scientific community ;)

    "It's not about the conclusions, it's about the process one uses to arrive at them" - j. anderson , aka: tkjtkj , Copyright 2010. Usage licenses available for $0.25 per event, inquire within.
     
  14. Mar 24, 2010 #13
    I guess I should have mentioned that I am not a scientist. I just have many questions that keep me up at night. Learning these things on my own is very hard without a teacher to guide me. So with this new knowlegde you have about my ignorence maybe you can answer my other questions.
    What is the role of dominate chenes in evolution? If a chene is a dominate one is this a form of evolution? Are brown eyes "better" than blue eyes? How is it decided what gene is to be dominate? I have tried to find the answers on my own but maybe this questions are to simple. i just want simple answers. If there is a mutation and it is better, is there a chance it will still not be passed on?
     
  15. Mar 24, 2010 #14
    Sometimes an inquisitive nature can be sooo strong that it can have a person expending harmful energies: eg, not being able to sleep because of a huge list of questions might be such a situation. It is plainly not healthy to have needed sleep compromised.
    I sense that your questions are unending , which is fine, as long as they don't begin to dominate one's life.
    I also think that a scientific view of things, which it seems you want to achieve, is not obtained by gathering a list of facts. I think that were you to find the time and opportunity to take some courses in genetics, even by some internet way, you'd become able to answer most of your questions by yourself: you'd gain the depth of understandings about mechanisms, etc, and answers to many of your questions would become obvious. More importantly, your then having a solid foundation in genetics might prompt you to think of new, alternative, explanations for the infinite number of questions that remain unanswered.. Who knows .. your ideas might significantly then advance scientific knowledge! On the other hand, your merely gathering a long list of facts would do very little toward preparing you for such adventures as science can provide.
    I admire your enthusiasm, but at the same time, i'd caution you to take a breather .. take time and think over how you might gain the comprehensive knowledge and tools to solve problems: that is what science is: problem solving. It's definitely not just a process for filling library shelves with facts. So, again, why not check out some nearby school, or an internet course in genetics ..

    Besides, you'd then sleep better ;)
    Nothing impels sleep quite as much as writing college term papers in the wee hours of the morning ;))

    Wishing you the best in your science adventures,
    I remain,
    j. anderson, md
     
  16. Mar 24, 2010 #15

    sylas

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    Science Advisor

    I think the word you want is "gene" rather than "chene". Evolution refers to heritable change from one generation to the next. It is not a form of evolution for one gene (actually one "allele", or variant form of some gene) to be dominant. There has to be something changing to be evolution.

    No. Or perhaps yes. It depends on the environment. The most likely way in which one color is "better" than another, in the evolutionary sense, will be if you are in a society where people tend to like one color better than another. In that case, the color might have an impact on how many children you are likely to have. So brown eyes will be better in a society where people find brown eyes attractive. Note that whether you find brown or blue attractive may also be a heritable feature -- though probably much more complex than a single gene. So there are some pretty complex interactions going on.


    Biochemistry. It will help to be a bit more precise in terminology. A "gene" refers to a particular functional location within your genome. For each "gene" there are a number of "alleles"; which are different forms of the gene, with a slightly different DNA sequence. Now because we have two copies of each chromosome, we also have two alleles for each gene... one from each parent. We say that one allele is "dominant" over another if when you have one copy of the dominant allele and another copy of the recessive allele, the effect is the same as if you have two copies of the dominant allele. The allele is recessive if you need both your copies of that gene to have the recessive form before it has an effect.

    Many genes are not quite that simple, but many others do have a simple dominant/recessive relation between the various possible alleles. This is simply a consequence of how the gene actually works in the biochemistry of your cells. Whether an allele is dominant or recessive is quite independent of whether it is advantageous or disadvantageous.

    Eye color (a bit simplified) is governed by a gene with two different alleles... a blue form of the gene and a brown form of the gene. You'll have two copies of that gene; one from each parent. If both of them are the blue allele, then you get blue eyes. If either one is the brown allele, then you get brown eyes. Thus the brown allele is "dominant" and the blue allele is "recessive".

    Yes, there is. A "better" gene (or actually, a better allele for some gene) is one that is more likely to be passed on, because having that allele means you are more likely to have more descendants. But it is still possible that you don't actually pass it on, and it is possible that it can even drop out of a population altogether. Being "better" only means it is more likely to be passed on.

    Cheers -- sylas
     
  17. Mar 24, 2010 #16
    WOW, thanks. All I had to do was say I am not that smart and I got everything I wanted. I guess sympathy is a great evolutionary trait of mine.lol i better get breeding.
     
  18. Mar 24, 2010 #17
    Well the dominant/recessive genes effect the phenotype of the organism. It doesn't really imply anything about the evolution because the 'evolved genes' could be recessive OR dominant, it all depends. This answers your second question as wel, if a gene is dominant it does not imply 'evolution', it just implies greater variance possibilities within our species. This may turn into evolution however depending on what's being selected for sexual reproduction. It's not as simple as 'oh a mutation has occured which gave me the ability to run faster,' that mutation ALSO has to make you a competitive and successful potential mate.

    Dominant genes may be selected for in order to 'squash' unwanted recessive gene traits. These are called autosomal-recessive genetic disorders. One which I know of off the bat is http://en.wikipedia.org/wiki/Phenylketonuria" [Broken] which can lead to mental retardation. It is more than just a 'single' problem though, if you look further into it but it is still an autosomal recessive disorder and you can see an image on the wikipage showing the inheritance of such a disease. Diseases can also be dominant genetic disorders too.

    Eye colour is more than just simple dominant/recessive genes, it involves many genes. Brown is the dominant phenotype though. Depending on where you live and where your parents are from will change the probability of inheriting one of many different eye-colour types.

    Nothing is decided in evolution, it just happens.

    If there is a mutation it doesn't make it automatically 'better'. It takes many of mutations in order for benefits to be readily noticable. (unless it's for resistance to viruses or disease which is noticable as soon as the event occurs) Most mutations are harmful however and by the way nature is set up will most likely not have a opportunity to be passed on. Genes that are neutral or beneficial have a greater chance of being passed on but it's no guarantee. Human cells also have the ability to correct these mutations when they are made directly from the DNA, this reduces the humans ability to evolve because it gets rid of the majority of mutations that occur indescriminatly.

    EDIT: I've noticed sylas posted an entire response as I typed this up. :rofl:
     
    Last edited by a moderator: May 4, 2017
  19. Mar 24, 2010 #18
    I wish more people who discussed this topic understood that.
     
  20. Mar 24, 2010 #19
    Yes, that is a good way of wrapping it up. It sounds a lot like a meditation in a way.
     
  21. Apr 1, 2010 #20
    Even that decision regarding when it should migrate would have had a random start right? Then by the copy-paste method(inheritance) of evolution, the organism follows the same decision pattern. Evolution doesn't postulate a sit-and-think model of life.
    For example, the development of horns in a bull several thousand(or million) years ago and the way the bull began to use it was random. Copy-pasting over successive generations resulted in bulls having non-random horns and using them in a particular non-random way.
    So i think evolution is all about random mutations which get inherited. Inheritance is the one that makes the process seem non-random. But the origin of changes is random.
     
  22. Apr 1, 2010 #21
    I have to disagree, mutations can occur at random but not all lead to Evolution of an organism. In fact the vast majority (in most species) does not lead to any change in the general population over any amount of time. So while mutation may be random (to some extent) Evolution is not.
     
  23. Apr 1, 2010 #22
    'Randomness' is *one* of the forces at work. Eg, if weeks prior to some catastrophe the food supply for the birds at their summer place was destroyed by 'legislative action', (voting is not a random thing, i think you'll agree!), the result might be two groups of birds: those who died for lack of food, and those who decided to migrate early , eg..
    Such a migration could be 'species saving' or even lethal, if the time of year were such that food existed at the endpoint of the migration.

    We must not carry the idea of randomness to inappropriate degrees.
    And why do you say that 'thought/thinking' isnt part of the story of evolutionary forces influencing survival? A smart Hutu (during the time of tribal massacres) who sensed the advisability of escaping early on certainly would be more likely to survive the mass killings.

    You might think that evolution is singularly based upon randomness but that is incorrect and is an idea not shared by science.

    Natural selection is the *opposite* of chance. The most significant forces at work in natural selection are three , and the first two (mutation and gene recombination) are quite random. 'Necessity' is the 3rd element. Natural selection happens in a milieu of the history of what adaptations have been successful in the past: and that by definition shows that it therefore can not be random.

    If you (a clever mathematician) and (not one) attend a casino, your history of knowledge of math makes your betting choices not random, or certainly not as random as mine might be. I.e., your history has modified what is possible for you to do .

    Likewise, for an organism to evolve, it had by logical necessity to have been able to survive to the point of time in question: this means that what follows can not possibly be entirely random. The 'possibilities' that the organism has to further evolve have been changed to be different from those of his 'siblings', as it were.

    The 'genetic background' of any evolving life form restrains as well as promotes future possibilities. Again, this, therefore can not be seen as 'randomness'. Even your computer as you sit there reading/typing away is incapable of any random act. It's physical construction , etc, requires it not to be able to do random things.
     
  24. Apr 2, 2010 #23
    Binbot,
    Your question is not unreasonable, and not hard to answer, and you and some of the folk in forum have been making some progress, but one problem is that it is a very old question, so some of them (like me) tend to groan.
    For a start, there is the question of just what randomness is. That is not as simple as it sounds, because there are a few ways of defining it. This is not because all or any of those ways are wrong (or right!) but because various ways of looking at the question suit different contexts. In evolution for example, yes, certainly randomness matters and plays major roles, but though there always are random factors (meaning mainly that we lack information on them and cannot correlate them with any clear function) there also are highly non-random factors (meaning that we can find correlations and make predictions with varying (but non-zero) levels of justified confidence.
    For example, a wolf bears a litter of say, eight cubs. One of them is clearly larger, stronger, livelier, and more cryptically coloured than the others. Now, suppose that the modal survival rate in that environment is say, one out of a litter of eight. I put it to you that you cannot predict which one will survive with even 50% confidence.
    Disagree? Because the cub plainly is a fitter specimen than any sibling? Think again! It just takes one inconveniently placed germ, bear, landslide, or rattlesnake, and our hero is meat, not even history! Some other cubs (if any) carry on the line. That shows that there is an element of unpredictability, no matter what the cub or bear or rattlesnake chose!

    However!!! Suppose you had to bet on which cub would survive in this litter - which one would be the rational choice? In spite of the random aspects that mean that you cannot predict with 50% confidence, in most environments that star cub would be the smart bet if you must bet! And certainly the parents must bet or lose! There certainly are random elements, but there also is enough information to affect the rational prediction.
    Of course, if the environment is slanted towards famine, we might prefer to choose a cub that looks as though it could stand hunger, but that does not change the rationality of choosing a likely winner.

    Now, given your interest, but lack of formal training (if I understood you correctly) I recommend that you do some reading that directly addresses your questions validly, but at a level that does not require a degree in related matters.
    Try:
    Dawkins: Climbing mount improbable
    The extended phenotype
    River Out of Eden

    Dennett: Darwin's Dangerous Idea

    Maynard Smith and Szathmary: The origins of life.

    There are many excellent books on the subject nowadays, and I don't hold much of a brief for any one in particular, but if any of those leaves you in much doubt, you will at least be able to discuss the matter more confidently in this forum.

    Jon
     
    Last edited: Apr 3, 2010
  25. Apr 2, 2010 #24
    Jon Richfield, I have to disagree with what you have posted. Genetic variation is possibly the only 'random' event that leads to evolution... however genetic variation in single organisms is not evolution. So that means based on genetic variation we can not conclude evolution is random. (Because most of these genetic variations are discarded) Evolution is partly based on the genetic variations so randomness does play a role but evolution is not dependent on random acts. That's to say, it doesn't matter what comes out of the genetic variations evolution will still happen.

    Natural selection is far, far from random. It doesn't matter if your hero bear died from a lightening strike or if it won the state lottery and moved to Cancun. No where in theories of evolution will you find that evolution specifically chooses larger, faster, stronger, brighter etc. animals over another. It all comes down to inheritance of genes, the animals that pass on their genes carry on the evolution of their species. Period.
    Nothing is random about this at all and over time it's clear that the animals that pass on their genes are the best adapted for the enviroment and have a higher probability of being chosen to mate with.
     
  26. Apr 2, 2010 #25
    Well, you are *sorta* right, in that genes must be inherited to allow natural selection to occur . .but the determining element is *natural selection* , not genes, not heredity, not anything else. I.e., does an organism have a competitive advantage, no matter how slight, over its niche-sharing brethren. .. And that situation, the *environment* is as critical as is the capability of an organism to survive. Both environment and the physical capabilities/characteristics are what allows *NATURAL SELECTION* to progress.

    If I have 100 fruit flies in a screen-mesh cage, half of whom have wings and half of which , by some mutation, lack wings, its the winged individuals which will survive. BUT: if i attach a fan to the side of the cage, (i.e., i change the environment) its then the WINGLESS that survive! Only they are able to complete mating, not being blown off by the 'high wind'.

    *ENVIRONMENT* is the 'filter' that determines which individuals survive.. and that *environment* can be called the *natural selector* !
     
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