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Beginner question regarding evolution

  1. May 24, 2010 #1

    I stumbled on your website when looking for a good place to ask educated professionals.
    I'm 16, I have a question on evolution.

    Ok so let's say there are these birds on an island with a food source that require long pecks, but these birds have smaller pecks than needed. So after a long time, I'm not sure to say how long, the birds have developed a longer peck, enabling them to reach the food source.
    Now, as I understand, mutations happen every day and most of them are harmless, and some of them don't even matter. Perhaps some small mutation in a stomach cell.
    I also recall that mutations happen randomly, and not in any particular part of the body for any animal. Just completely randomly.
    So how can these birds develop with themselves this long peck, even if they have millions of years to do it? A single, a single part in their body being transformed beneficially? And how come the animals don't have extremely weird shapes (within each species) if mutations happen completely randomly? Why are the ears on the same spot in almost all human beings? I understand that if the human is too weird looking, he might not be able to get a mate. But a little weirder looks would happen if it would happen randomly, right?

    Don't think I'm against evolution, this is just something I can't grasp. I'm a pantheist, so I believe in evolution.
  2. jcsd
  3. May 24, 2010 #2
    The ones with long beaks get more food, more strong, more able to survive and reproduce and thus contribute this trait to the lineage at the expense of the lil' ones that get hungry, weak, and die. It is however about averages and populations as a whole: on average, the long-beak population will be more successful than the small-beaks if the food source is more available to long-beaks, and after many generations, the proportion of long-beaks will start to dominate since these will have had a better chance for survival. And once they begin to dominate, additional factors affect the appearance of the trait such as sexual factors: the female will grow to know longer beaks are a better mate for her offspring, further decreasing the proportion of the small-beak trait. At some point, the population of small-beaks reach a critical point, beyond which the slide to extinction becomes likely.
  4. May 24, 2010 #3
    Thanks for answering! But what about the latter part of the question, about the similar appearance of all humans?
  5. May 24, 2010 #4
    That's not very clear what you're asking. Ears are at the same spot because that spot was selected as an advantageous trait in our evolutionary history. Genetic machinery guides this process and those genes were selected by the favorable advantage to survival and reproductive success imparted by that location.

    Look at any trait in any species, and at some point in its evolutionary history, the trait was an advantage to survival and/or reproductive success.

    Live and evolution is all about survival and reproduction.
  6. May 24, 2010 #5
    But people seem to fail to account that those mutations, at least as proposed by mainstream evolution, are random and in both ways, they can be positive and negative.

    Then, they are settle, and lets say one species evolves its beak to be 0.1 mm bigger, that would hardly give it such an edge compared to other species, nor does it mean all species with 0.1 mm shorted beaks will become extinct.

    Then, that one unit that has its beak 0.1 mm bigger will mate with another unit that has its beak 0.1 smaller, and hops.... there goes the advantage

    And finally, what if evolutionary changes are not random, but susceptible to determination to a certain level, by the actual species? That would allow for accumulating positive features much easier than a settle random process that goes both ways and is effectively canceled out, as its effects are too settle to make a big difference over one or even a few generations?

    Does the bigger beak evolve randomly, against common logic, or does it evolve bigger because the species need it?
  7. May 24, 2010 #6
    And I thought I had it all figured out :( I hope someone answers this question aswell
  8. May 24, 2010 #7
    If you want a good grade, you'd better stick to what you are being told at school. You can explore other possibilities, but the educational system is unlikely to reward you for it :) You can still present the mainstream version in tests, and work out alternatives for your own intellectual benefit :)

    The idea is those random mutations give such an edge to the species it affects, that they get way more competitive and push out the rest who don't have that mutation
    It doesn't make much sense considering what I wrote in my first post here, but thats the way things are.. for now. I sure wish evolution was the only aspect of science I find rather unconvincing :) Keep in mind it is an old theory, and even Darwin had his doubts, which are reflected in his journals.
    Last edited: May 24, 2010
  9. May 24, 2010 #8
    Thanks for all the answers! I'm definitely going to ask here again if I have any problems.
  10. May 24, 2010 #9
    Mutations are random and are either positive, negative, or neither.

    Can't say that. 1/10 mm could have an advantage. But maybe it wouldn't. But mutations are not all like that: one mutation could cause the beak to be several inches difference with just one birth. And there is still chance nothing would come of this individual but also chance it would mate with it's smaller-beak comtemporaries and could cause the off-spring to have a much larger beak than the parent with the smaller beak. And if it's a very successful trait leading to easier access to food, then these individuals would have an advantage over other small-beak individuals. But again, they could mate with small-beak partners or even another large-beak and still have off-spring with small beaks. It depends on how the gene is expressed and how successful it is in confering advantage to it's owner. And really we need to view this in terms of a population and not just one or two individuals. It's the population as a whole that evolves, not the individuals.

    No. Mutations are random. Use "subtle" not settle.

    It evolves because it has a selective advantage towards survival and reproduction. Species don't "need" anything. Rather they have random changes in their DNA which is then presented to nature which then selects or de-selects the trait based on it's ability to affect survival or reproductive success.
  11. May 24, 2010 #10
    You said it - mutations can go both ways. Chances are 50/50 and cases of rapid and well pronounced mutations are very, very rare. You have mutations going both way in one population - you will get those advantages compensated by disadvantages. And as I said, one generation of "subtle" mutation could not possibly make an individual stand out, as there are many other factors. For example one unit can develop a little bigger beak, but be a little less agile and that could render the beak advantage useless.

    Crossbreeding patters over generations can however result in species that have an edge, but they will also be carriers of bad genes that could potentially bring an end of their successful lineage as generations shift.

    Truth is we cannot know for sure, as those changes happen in very long periods of time.

    There are MANY observations that support my view, for example in forest fires butterfly population seems to mutate to change its camouflage so it doesn't stand out on burned out tree trunks and thus become easy prey. There is no process of some butterflies changing to "burned tree color" while others are changing to PINK, YELLOW or any RANDOM color. The "mutation" is not random, it is exactly what that species needs badly to survive.
  12. May 24, 2010 #11
    I agree that useful mutations are rare.

    I suspect more likely the population of butterflies had a diverse range of coloring to begin with and the change in environment only selected from that population, the darker-colored ones by giving them an advantage to predation. I do not believe they changed suddenly in response to the darker trees. However I am familiar with the moth population in England which because of the industrial revolution, gradually changed from white to a dark color which gave them a survival advantage on the soot-covered trees. These however were still caused by one or more random mutations with the gene frequency in the population for that trait increasing gradually over many generations giving rise to the predominant darker color.
  13. May 24, 2010 #12
    Do you have any plausible ways of proving that evolution is random and its direction is not being determined by the actual needs of species?

    Life seems to rapidly adapt to change of conditions, and that can be driven by the actual species requirements. When conditions change, species cannot afford to wait millions of years for small random mutations to build up to ensure their survival. Also, as you said it - RARE

    For example, did the giraffe long neck evolved as a random mutation, or their predecessors were constantly stretching their heads up to reach vegetation, and their genetic material has adapted ALL giraffes to evolve longer necks? Or you suggest there were also short neck giraffes that died out because they couldn't compete?

    Why is it so scientific to believe in chance and coincidence, rather than the unique adaptability of life, which is in plain view so often?

    Conditions on the planet have been changing so dramatically over the course of history that life could hardly endure if it wasn't adaptable and had to solely depend on chance and random and minuscule mutations, which are usually so slow they could never save spices from extinction.

    IMO there is a certain degree of intelligence to evolution. There are also random mutations, but I don't think it is them who drive the direction of evolution.

    One thing I learned thou - the b in subtle is mute - 10x for that correction
    Last edited: May 24, 2010
  14. May 24, 2010 #13
    I think any Biologist you ask would tell you evolutionary change is entirely random and subject to chance. In fact, I saw Stephen Gould shortly before he died. He used the term "massively contingent" in that talk to describe the randomness of evolution. I've used the term often ever since.

    Do it quick enough it won't.

    Usually the changes are moderate except during one of the several massive extinctions in history in which cases they do not change and most die. At one time, the human population had almost become extinct with estimates of only a few thousand left at that time. We recovered.

    Know what, I don't know exactly how it got so long. I suspect is was a combination of chance mutations, and selective pressures and I suspect it was gradual over many thousands of years although as I said I do not know for sure.

    It didn't endure millions of times in evolutionary history. I'm sure you realize billions of species have become extinct since the origin of life. Sink or swim.

    You're just humanizing a natural phenomenon. There is no intelligence what so ever behind evolution.

    Interesting talk. I like evolution. Makes sense to me. But I'm older than you and have studied it longer. Twenty years from now, you'll look back and say, "Jack was right. He was being solid with me." :)
    Last edited: May 24, 2010
  15. May 24, 2010 #14
    I asked about a plausible proof, not about what every person, milled through the educational system will tell me. I know what the textbooks say ;) If you are into writing I guess there is no point of explaining the meaning of the term "conformity" then? :)

    Being able to make "decisions" (figuratively said) based on your surrounding environment is not strictly a human attribute. So no, I am not humanizing anything.

    I think it is about 95% of all species ever lived that are extincted today. But most of them were extincted in the major extinction events with very few exceptions. Plus some changes in conditions are way too rapid for life to adapt. You won't grow fur overnight if the climate changes to cold. But species tend to adapt to the cold fairly quickly, which is a natural process, it's not like they are waiting for some random mutation that is rare and might take millions of years so they grow more fur.

    Evolution is a theory that has not been set in stone, sadly few people have the privilege of being taught by professors who share that fact with students. There are way to many inconsistencies for evolution to be fully accepted scientifically, now if you are a "believer" that's a totally different story :)
  16. May 24, 2010 #15
    I see you have doubts. Evolution however for me is absolute; I have no doubt about it and if you keep studying life, you'll get there too. Something else will happen. Sorry, can't explain it. In time you'll see what I mean if you keep an open mind. :)
  17. May 24, 2010 #16
    It is strange, considering even the father of evolution had his share of doubts. I guess you are a believer then, my mind is open to all possibilities, which spawned this interesting discussion, it seems that it's your mind that is shut to everything besides the mainstream :)

    It is in our nature to question, especially when there is evidence suggesting controversies. However, as I advised the starter of the threat - if you are after recognition from the mainstream, you'd better conform to it.

    My approach to studding life is more Polymatic, I found connecting the dots between the scientific and the artistic to be way more beneficial to me.
    Last edited: May 24, 2010
  18. May 24, 2010 #17
    I'm sorry. I thought you were the original poster and if I implied you're younger than me and are not then I apologize.
  19. May 24, 2010 #18
    No need to apologize, plus I am probably younger than you anyway, your longer career suggests that :)
  20. May 24, 2010 #19

    D H

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    Evolution is a very new science, about 150 years old. Darwin was the start, not the end. Even though it is a young science it has been turned upside down at least twice in its short history. Darwin didn't know about genetics or about DNA.

    You, dgtech, are the one making extraordinary (and extremely outdated) ideas. The burden of proof is upon you to justify these claims.

    You are talking about Lamarkian evolution, which is an outdated idea. You need to read up on population dynamics.
  21. May 24, 2010 #20
    Your points are valid, but the assumption that I went into exploring alternatives before studding the mainstream theory is a hasty one. I accidentally used the giraffe, which is a typical Lamarkian example, but my idea wasn't that the actual giraffe is passing characteristics, but that the actual process of evolution might be environment aware, after all the organisms is a collection of interconnected systems and is also connected to the environment, so changes in the environment create changes in the organism which can be translated into genetic changes. It is a chain reaction, and with such a large portion of our DNA being regarded as JUNK no one can claim to know for sure if that is plausible or not. It is an open chapter.

    I have a lot to say in order to support my view, but that would simply bring me more infraction points, and I have plenty ;) Plus no one would even benefit from the information I provide, as you will likely erase the post.
    Last edited: May 24, 2010
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