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Questions about evolution

  1. Nov 8, 2012 #1


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    Hey guys
    I was in a discussion with my friend and I couldn't answers some questions about evolution .. and since I'm not that good in biology, I hope that I get some explained answers.
    Q1 : How can mutations produce organs ?
    Q2 : Do genetic mutations produce positive and negative changes ?
    Q3 : Are there bad designs that could be an evidence for evolution ? ( please name some examples and explanations )
    Q4 : Can gene mutations be inherited ?

  2. jcsd
  3. Nov 8, 2012 #2
    Using words like design have little to do with biology. What would you consider a bad design? Would you consider someome with absence of a limb or birth defect a bad/poor design or simply a genetic problem. It is such a useless thing to talk of design in biology. Yes most things in biology appears to have a function. Maybe you should learn about vestigial organs.


    What do you mean by positive and negative changes ?. Mutations are just change in a nucleotide sequence. In biology we talk whether they are neutral, deleterious or advantageous.
  4. Nov 8, 2012 #3
    Q4: Yes, by definition.
    Genes are units of heredity. A mutation, by definition, is a spontaneous change in a gene. A spontaneous change in a unit of heredity can be inherited.
    Q3: “Design”, good or bad, can not either prove evolution or disprove evolution.
    No matter what one sees in the universe, one can explain it by hypothesizing gods with personalities matching the observations. Let us look at mythology. Gods can design things badly. Gods can even be stupid. Gods can also hate other organisms. So a “bad design” could be considered evidence for a god that is stupid, makes mistakes, is malevolent and intentionally misleading. If one accepts the possibility that the creators of the universe can be all these things, then one can not accept bad design as proof against evolution.
    Q2: Good and bad depends on the environment that an organism is born into. Saltations are mutations with a very large effect on morphology. Saltations are almost all bad in every context because they usually over extend some feature. However, a small mutation has a significant chance of being useful.

    Just one example out of many. Webbed feet on animals.
    Webbed feet can be very good for a bird that wades in the ocean for food. Webbed feet can be a nuisance for an animal that hunts in a dry desert.
    Webbed feet, as a first mutation, can be both good or bad for an animal that lives on a sandy beach. A second mutation that affects the behavior to make the animal choose either water or sand can make the webbed feet more useful.
    Webbed feet are something that can be good or bad depending on context. If you are willing to call the webs between toes an organ, then the webbing between toes is an example of an organ that can be generated by mutation. Labrador retrievers have webbing between toes. This is not something that all dogs have.
    “The feet are strong and compact with webbed feet which aid the dog in swimming.”
    “Bushy, shaggy tails with webbed feet and an oily coat make the Golden incredibly fast swimmer.”
    Human beings did not directly influence the mutations that gave the labrador retriever webs between the toes. They may have provided some selection once the mutation occurred. However, natural selection could have also given the breed webbed toes.
    Note that webbed toes can be harmful in an environment where the dog has to dig or climb, as some breeds do. Also note that the mutation would have been the first dog with webbed feet, not the later dogs that inherited this mutation. Mutations can be inherited, or they wouldn’t be called mutations.
    A mutation that made very large and thick webs between the toes, so that motion was inhibited, would be very bad. A small increase in skin area could be useful while swimming, and not to harmful while digging.
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