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Does a human being ever evolve during his lifetime?

  1. Jul 28, 2012 #1
    Maybe not on the macroscopic level, but what about on the molecular level? Is his DNA gets mutated by radiation from computer monitors, does that mean he has "evolved"?
     
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  3. Jul 28, 2012 #2

    phinds

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    I think you have to defined exactly what you mean by "evolved" in order for that to be answered.

    In terms of long-term human evolution, I think the answer is no, but there are other definitions, such as exemplified by the phrase "his position on integration evolved as he grew older", which would allow for evolution, in some sense, within a single lifetime.

    So what DO you mean?
     
  4. Jul 28, 2012 #3

    phyzguy

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    Remember, your body is composed of trillions of cells, each one with its own DNA. So the DNA of one cell can "get mutated by radiation from computer monitors", but this does not affect all of the other cells. Individual cells, or groups of cells can definitely "evolve" within your body. Cancer is when a cell evolves to override the built-in limits on cell growth and this cell and its offspring then grow without limit. So this cell and its offspring are "evolving" within your body. Also, your immune system works in part by having clones of cells which evolve in response to foreign antigens.
     
  5. Jul 28, 2012 #4
    Mutations occur with or without radiation. It occurs naturally , majority of the mutations are not harmful or silent.

    http://en.wikipedia.org/wiki/Mutation
     
  6. Jul 28, 2012 #5
    The straightforward answer to the question posed in the thread title is no. Evolution does not happen to individuals, it happens to populations over time. Reading your post it becomes clearer what it is that you are missing. There are two elements to evolution, an origin of change and a selective mechanism. In the case of the biological evolution of life, the origin of species change is genetic mutation. But that in itself does not constitute evolution. Genetic mutation alone cannot tailor species to their environment. It is the much misunderstood selective processes that collectively are called ‘natural selection’ that tailor species to their environment. And it is selection that cannot operate on an individual. An individual is either dead or alive. Populations can consist of proportions with features that offer selective advantage. And it is the better chances of survival and of reproduction that those individuals with a selective advantage that means that, over time, species tend to become better and better adapted to their environment.
     
  7. Jul 28, 2012 #6
    Lets not forget even if mutation does happen it will probably in your somatics cells rather than the germline cells that go to your descendants.
     
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