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My thoughts of evolution and help me to correct them.

  1. Jun 22, 2010 #1
    DELETED because of immature thinking :(
     
    Last edited: Jun 22, 2010
  2. jcsd
  3. Jun 22, 2010 #2

    mgb_phys

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    There is a slight misconception - species don't evolve to fit their environments, that is a side effect (although a good way of picturing the result).
    Species evolve to have more babies, a change which results in more babies means the change will be passed on to those babies and so the change will become widespread - it's really your genes that are evolving not you.

    In this sense humans are most likely to evolve an immunity to the contraceptive pill rather than physically change to their new concrete jungle environment.

    There are examples of evolution over human (even historical) timescales. In some cultures red hair is considered luck, so a red haired person is more likely to find a date and have more children, hence pass on the ginger gene - so lots of red haired people in some celtic cultures. In others red hair is considered bad, so less likely to marry and have children - red hair dies out.
     
  4. Jun 22, 2010 #3

    Ygggdrasil

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    One example of human adaptation to "modern" (or at least relatively modern) society is the adaptation to drinking milk. Our ancestors did not have domesticated animals and therefore did not eat dairy products. So, adults were normally lactose-intolerant. While children produced the enzyme necessary to digest lactose (lactase) from their mothers milk, the body turned off the production of this enzyme went away during adulthood when it was no longer needed. However, in human populations that developed agriculture and were able to domesticate animals, people whose bodies did not turn off the production of lactase had a selective advantage and therefore the genes for lactose-tolerance became more prevalent among those populations.
     
  5. Jun 22, 2010 #4

    Borek

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    As long as there is no selective pressure this is unlikely. At the moment having 6 fingers and being able to type faster doesn't make your chances of reproduction (or chances of your kids surviving) higher. The day it will change we will start to adapt.

    But there more subtle changes - those better educated (which often, athough not always, means smarter & better organized) have less kids, while lazy bums living off social support multiply like rabbits. Assuming kids are similar to their parents, that can mean next generations can be on average more stupid than we are.
     
  6. Jun 22, 2010 #5
    Thanks for clearing some doubts. Decided to "close" my thread because i felt that it was such a joke :(
     
  7. Jun 22, 2010 #6
    Biologically speaking evolution is just the change in gene rates on the population. For a biologist, evolution is just change, never improvement.
    There is too much misconception on your knowledge to point out.
    Think an animal as a bag o genes, if they can pass to future generations their genes they are successful. On city environment, there is no restriction on transmitting their genes.
    Best,
    Alex
     
  8. Jun 22, 2010 #7
    I wouldn't be so quick to delete your misconceptions sharkey, this is how you learn. Now, the ability to resist HIV infection could be an evolutionary event, and there are a small number of people in documented as being resistant (immune is too hard to confirm). This could allow them to pass genes to a much larger population, but if they live and participate in a monogamous society, it doesn't matter right?
     
  9. Jun 22, 2010 #8

    Borek

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    Yes and no - depends on when HIV kills. If you survive long enough to reproduce and raise your kids, resistance is not that important. I think in some cases living short is beneficial to population, as it means it can adapt faster (more generations in a given period of time).

    Doesn't matter. If monogamous pair has more surviving kids, evolution works as usual.
     
  10. Jun 22, 2010 #9

    russ_watters

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    You should not feel insecure about not knowing all the answers, you should feel proud that you have the self-awareness needed to challenge your own preconceptions and work to expand your knowledge. This is an extremely important life-skill that some people never learn.....and fostering that is one of the key purposes of this forum, so you shouldn't feel ashamed about displaying that trait!
     
  11. Jun 23, 2010 #10
    That's a good point, but imagine Uganda for instance, and this immune or typhoid-mary individual (male in this case) survives for decades without drug therapy. He is promiscuous, and often fails to use condoms. In a changing environment that could be a great adaptation, but there would need to be a great pressure on the population, where the need to repopulate was an issue. Historically that isn't beyond belief. At the moment you would appear to be correct, but again, if children can be born with the ability to resist a pandemic that kills them without drug therapies before they can procreate, you might find bubble communities. In the case of HIV I've worked myself into a corner however, given that it is so prone to rapid mutation, a human reservoir would seem unlikely.

    Russ_Waters, well said, any way to un-delete his original post? I'd love to be able to engage him more fully, but I can only go on hints from quotes by others.
     
  12. Jun 23, 2010 #11
    Yes Admin.. please repost the OP's question.
     
  13. Jun 23, 2010 #12

    Borek

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    As far as I know edits are not saved in the database. But I can be wrong.
     
  14. Jun 23, 2010 #13
    Now that is a pity.
     
  15. Jun 25, 2010 #14
    The more important factor would be genetic isolation. If humans did not interbreed with isolated populations and were under very different selective pressures this would be more likely to give rise to a diff. type of human (speciation). The large scale changes that undergo a single large widespread population that does interbreed would be very difficult to interpret.

    And a big WOW to your second paragraph...
     
  16. Jun 25, 2010 #15
    Wow, and yet accurate.
     
  17. Jun 25, 2010 #16
    Accurate how? Accurate in that people in the US with lower incomes do have more children per family than people with higher incomes. But the rest, speculation. And fairly bold speculation. Which is provacative therefore fun imo.
     
  18. Jun 25, 2010 #17
    I wasn't aware that Borek was limiting his observation to the USA, but the notion that children raised in poverty and, lets say, stupidity might carry on that legacy is speculative, but not overly so.
     
  19. Jun 25, 2010 #18
    This is a nature v. nuture argument. Being raised in poverty implies a stupid genetic component? And what the heck is stupid exactly, how is this assessed?
     
  20. Jun 25, 2010 #19
    He may not have been (the US thing). I just have seen the stats on this for this country.
     
  21. Jun 25, 2010 #20

    lisab

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    It doesn't have to be genetic. Stupidity can be caused be ignorance (i.e., a lack of education).
     
  22. Jun 25, 2010 #21
    The bolded implies a genetic component unless I am reading it incorrectly. And it is under a topic concerned with evolution...
     
  23. Jun 25, 2010 #22

    Borek

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    I am thinking about genetic component. Since the dawn of civilization usual evolutionary pressures were removed, so one could think evolution stopped for us as a species. But it has been theorised that actually those smarter were able to leave more progeny, therefore increasing our average IQ. Could be this process is working in the opposite direction now.
     
  24. Jun 25, 2010 #23
    I dont know what smarter is in todays world. The idea of smarter 200,000 years ago when basic survival was tough is a little bit easier to define. Defining smart on the basis of an IQ test is a really thin slice of what I would deam smart. Does an IQ test measure the ability to read people and manipulate them? Does it measure the ability to get a group of people to do the bidding of an individual? Does an IQ test measure the ability of a person to work for long periods of time and their resourcefulness and endurance in performing numerous tasks. There are so many ways to define intelligence or smart and then trying to put into a category so as to define its evolutionary signficance in a world that we currently live in is imo a daunting task.
     
  25. Jun 26, 2010 #24

    Borek

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    I am aware of IQ limitations, and I would not dare to define smarter. But I prefer to live in a world full of people trying to push our civilization up and ahead, instead of trying to pull it down by overmilking. In this context if you are not aware of the fact that overmilking the system you are killing it, you are not smart.
     
  26. Jun 26, 2010 #25
    So people who run businesses based on the quick profit motive and then get out once the damage to society has been done should also be mentioned as milkers I guess. In fact they may even do more dumb damage per capita so they might be considered very stupid.
     
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