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Query on the God Delusion Book

  1. Jul 6, 2011 #1
    Folks,

    I came across an extract Steve Grant on page 416 of the God Delusion by Dawkins See attached photo.

    I dont quite understand what he is saying about us being waves. Could some-one give me a physical explanation what he meant?

    I realise that the actual age of our body is not from the day we were born because the cells keep regenerating etc but I cannot extent the idea to the extract.

    Thanks
     
    Last edited: Oct 26, 2011
  2. jcsd
  3. Jul 6, 2011 #2

    Evo

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    It's a really serious mistake on the part of Steve Grand. Although many of our cells die and are replaced it simply isn't true that there is 100% replacement of all cells in the human body.
     
  4. Jul 6, 2011 #3
    So if my wife catches me at something I can always say that it wasn't really me?
     
  5. Jul 6, 2011 #4

    Ryan_m_b

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    Whilst true it is unlikely that any of the sub-cellular components of the cells are the same, all the biochemistry making up a cell is eventually recycled. I've never encountered a biological process that allowed something to be statically stored in the body.
     
  6. Jul 6, 2011 #5

    Evo

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    To my knowledge, there are certain cells in the body that do not get replaced, such as the inner lens of the eye, some parts of the heart (recent research by Jonas Frisén shows that some cells of the heart do get replaced, however at a very slow rate). etc..

    Since you are the expert on this, I'm moving to Biology. You most likely have the most up to date studies, and I'd love to have more recent information since this is a topic I am interested in.

    My links

    http://www.medicalnewstoday.com/articles/144917.php

    and

    http://www.ncbi.nlm.nih.gov/books/NBK28372/

     
  7. Jul 6, 2011 #6

    Ryan_m_b

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    You are correct, there are indeed cells that last a lifetime, or at least cannot be renewed. However even if these cells themselves are not swapped they do regenerate their components. From the second reference you posted;

    So over time these cells will have no constituent molecules that were there a set time before (even though at no point was the cell itself "gone"). Part of the problem with these http://en.wikipedia.org/wiki/Ship_of_Theseus" [Broken] thought experiments is that I am unaware of any study that has drawn together research to show exactly how long it takes the body to get to a state if having no atoms within it that were there X time ago. I'm not even sure how well this could be done, it's possible that some atoms by chance stay with us throughout life so it may be more appropriate to consider the idea of renewal as probabilistic rather than mechanical.
     
    Last edited by a moderator: May 5, 2017
  8. Jul 6, 2011 #7

    Evo

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    I guess until we can run studies on humans with excessively long lifespans, we won't really know for certain. But based on what I've read, that even being in my early 50's I still have some original material.

    Of course Grand was trying to make a point that physically we change, but wasn't 100% correct as far as our current knowledge goes, and what's the point? (yes, I hate philosophy)
     
    Last edited by a moderator: May 5, 2017
  9. Jul 6, 2011 #8
    ok, so based on the replies given can we conclude that there is a probability that the sub components of a cell including atoms are eventually replaced?

    Sorry I missed the previous thread. So the answer is theres a strong probability that some sub components of cells remain with us and hence we are nevered completely renewed. Thanks
     
  10. Jul 6, 2011 #9

    Ryan_m_b

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    I would say it is extremely unlikely that there would be some component that is never excreted. However the point is largely irrelevant, if all of the atoms in Alice's body when she dies were not there when she is born is there any real difference if Bob's body has a few carbon atoms locked in some proteins?
     
  11. Jul 6, 2011 #10

    Evo

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    Good answer!!
     
  12. Jul 6, 2011 #11
    ok,

    thanks folks!
     
  13. Jul 7, 2011 #12
    Say you have a glass tank and a single wave moves from left to right through a water medium in that tank. The atoms that started out being the wave on the left are not the same as the atoms that make the wave in the centre, or the atoms that are the wave on the right. Even though it is one and the same wave, it was made up of different pieces throughout it's lifespan (distance from left to right).

    You are similar in some respects to the wave.
    As you progress though life, your atoms, at varying stages and rates, may be replaced. What's important, what makes you, is the arrangement of those atoms at any given stage.

    What the athur is trying to get across is that you aren't actually a "physical thing". What you consider to be you, the matter you're made of, is simply a medium through which you propogate.

    At least that's my impression.
     
  14. Jul 7, 2011 #13
    I see....
    That is a tricly one to follow/imagine! Is this the generally accepted view on this for all living organisms?

    Thanks
     
  15. Jul 7, 2011 #14
    Yes it is. No living system is static and components have to be replaced, added or removed in the course of metabolism, reproduction and repair.
     
    Last edited: Jul 7, 2011
  16. Jul 7, 2011 #15

    Ryan_m_b

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    I would hazard a guess that this is true of most things. For instance;

    A river (never the same water nor the exact same path)
    A nation (people are born, live, die)
    Land (nutrients go in and out of the soil)
     
  17. Jul 7, 2011 #16
    Hi, I had to pull off the shelf my hard copy of The God Delusion by Richard Dawkings. Has anyone besides myself read chapter 10 "A MUCH NEEDED GAP?" wherein the OP's attachment is located?
     
  18. Jul 13, 2011 #17
    The impression I often have is that it appears to be true for all things. The only difference between any two given systems in this seems to be the time which needs to elapse before the pattern becomes distinguishable to human observers.

    By the way, RyanMB, I wanted to take the opportunity of having a biologist in arm's reach to ask a question which has been on my mind since viewing a video about an evolutionairy phenomenon known as "Ring Species".



    What I've wanted to ask a professional biologist about this is whether or not it is possible that this "Ring Species" phenomenon could also occur within humanity over a sufficiently long passage of generations. I.e.: Would it actually be possible that the so-called "races" of the human species (generally subjectively designated along the lines of "white", "black" and "yellow") can genetically diverge to such an extent over time that men & women from these groups would no longer be able to interbreed with one another?

    The reason I can't quite get this out of my mind is because, as my name might already suggest to a biologist, I am a person of somewhat mixed heritage myself. In the end, we humans are a part of the cycle that we observe in nature. Therefore I wanted to ask you: Is there a reason to assume that these same rules do not (or do not any longer) apply to us, or is indeed possible that humanity may be heading towards a status of Ring Species at one point in the future?
     
    Last edited by a moderator: Sep 25, 2014
  19. Jul 13, 2011 #18

    DavidSnider

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    It's possible, but not likely, since there are no physical barriers to interracial breeding. Humans can hop across the globe in under a days time. Too much possibility for gene flow.
     
  20. Jul 14, 2011 #19

    Ryan_m_b

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    Potholer54 is a great channel :smile:

    At one point there were http://en.wikipedia.org/wiki/Homo#Species", the level of interbreeding between them ranged between zero to little. It's only been in recent history (~10 kiloyears ago) that Homo sapiens became the only species left.

    The reason ring species allow speciation is because we have http://en.wikipedia.org/wiki/Mutation" [Broken] between populations. The geographical separation allows the species to diverge.

    As DavidSnider correctly points out this no longer applies to humans. Thanks to our technology and society there are no geographical barriers to interbreeding. If a population of humans were to be isolated then after a while they would speciate from the rest of us.
     
    Last edited by a moderator: May 5, 2017
  21. Jul 14, 2011 #20
    That is astonishing. If I understand you correctly, then the so-called "Ring Species" phenomenon has in fact already occurred within humanity in the distant past, and all the people on Earth today are the descendants of the sole surviving variation of "human"?

    That seems to raise some questions of its own. In the case of us modern humans, the effect of geographical seperation seems at least to some extent to have become emulated by various means of birth control, cultural doctrines (and resulting peer pressure), policies & laws (more of a thing of the past now), etc. I am about 1/4th Native American from my mother's side (Standing Rock), and having been raised mainly by my grandparents in my youth I've come to know firsthand the impact of the blood quantum. (How strictly it is applied can vary a lot depending on the tribe in question, however.)

    What fascinates me as a mildly mixed person is that in the last twenty years or so, the cultural and political climate arguably has never appeared to be more favorable towards interbreeding between humans. Yet, when I examined the recent Census data for the United States (2010 statistics), I found that under these conditions too interracial marriages remain something of an absolute minority. Assuming their current level of growth persists, it will take a very long time before they come to represent for example 25% of the total marriages each year.

    In that scenario, about 75% of the population of the various ethnicities still remain in a state of little to no interbreeding as time progresses. The impression I get from this is that the only real obstacle speciation faces in occurring once more among humans is that we likely won't survive the next few millennia to begin with, considering the way we have come to treat our world. (Not to mention each other.)

    This seems to be increasingly moving into the territory of anthropology and sociology, so I should probably stop hijacking this thread. Thank you for the responses, and especially for those Wikipedia links! They will likely result in hours of reading pleasure on my part.
     
    Last edited by a moderator: May 5, 2017
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