Natural selection past the reproductive age

Discussion in 'Biology & Genetics' started by spuriousmonkey, May 17, 2004.

  1. paulsamuel Registered Senior Member

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    well, one needs to be exacting in one's language in disputations such as these, else language and semantics present obstacles to understanding.

    so, we agree that genes are not manipulating the individual of which they are components. Since genes are not manipulating the individual, then the individual is acting in its own best interest given the evolution of its phenotype by natural selection.

    then, i guess i'm not clear on why you disagree?

    I see now where you are confused. An individual is most certainly NOT merely a collection of their genes or their gene products. There are emergent qualities of an individual. BigBlueHead alluded to this in an earlier post but you will need to address it. Genes and gene products interact with other genes and gene products in different ways and this is reflected in the phenotype (see epistatic and pleiotropic effects). This depends on the environment: the physical, ecological and genetic environment in which the individual finds itself.

    S.J. Gould wrote about this in his book, The Structure of Evolutionary Theory, in the section entitled, "Attempts to Assign Agency to Genes by Denying Emergent Properties to Organisms," pp.627-628.

    The argument is delivered as follows;

    gene-selectionists believe that genes propagate via selection on organisms as interactors with the environment because "each gene stands as an optimal product and that bodies, as carriers, impose no consequences on genes." The view that the body is "a passive aggregate of genes," and selection on a body is a pathway for selection on all genes considered individually. this can only be true if interactions with other genes, or the environment, are additive. Any nonlinearity leads to emergent properties. Thus, when selection works on these emergent properties, then causal reduction to individul genes becomes impossible.

    I have to go to bed. I'll finish this tomorrow.
     
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  3. John Connellan Valued Senior Member

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    Exactly. I guess I AM denying emergent properties to organisms then. I must take a look at that book sometime. I presume it would be available in most university libraries right?
     
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  5. paulsamuel Registered Senior Member

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    yup, and you can get it at Amazon.com for less than $30.
     
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  7. BigBlueHead Great Tealnoggin! Registered Senior Member

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    Paul - thanks for the correction on the evolution/selection thing... I gotta be more careful of that.

    John - don't deny emergent properties out of hand - that phrase takes in a lot of selective advantages, especially for humans...
     
  8. John Connellan Valued Senior Member

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    I wish I COULD get stuff like that online at Amazon but I don't have a credit card (we have to pay stamp duty of E40 on each card here) and I tried paypal but they don't allow transfer of funds from an Irish bank account into my paypal account! I could open another account in the UK or US but do u have any idea how I would go about doing that online?!

    Bit of a change of subject here

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  9. BigBlueHead Great Tealnoggin! Registered Senior Member

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    Use a credit card? But I don't know how easy it is to get a credit card in Ireland.
     
  10. John Connellan Valued Senior Member

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    Like I said........... its too expensive

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    Im not paying the E40 for a credit card coz Im a student and I doubt I'd use it that often
     
  11. BigBlueHead Great Tealnoggin! Registered Senior Member

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    Try to find another escrow service that can transfer to PayPal, and do your bank transfer to them instead. (I know, two escrow services is a little eccentric, but if it works you can get your book.)
     
  12. John Connellan Valued Senior Member

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    I have had a look at the escrow website but really, I can't make sense of it at all. I can't believe how hard it is to send money online here in Ireland. I guess u could say we're still in the primitive internet days here. Its ridiculous.
     
  13. BigBlueHead Great Tealnoggin! Registered Senior Member

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    Sounds like a business opportunity to me John! Get cracking!
     
  14. John Connellan Valued Senior Member

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    LOL, very true. Theres too many business opportunities opportunities on this island u know that?!

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  15. BigBlueHead Great Tealnoggin! Registered Senior Member

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    I guess that's the "Luck of the Irish" they tell me about.
     
  16. John Connellan Valued Senior Member

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    Yeah u just gave me an idea for the "paradox" thread in the philosophy section LOL
     
  17. paulsamuel Registered Senior Member

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    Great thread!

    I like threads with resolution, and everybody learned something!!!

    Sweet!
     
  18. BigBlueHead Great Tealnoggin! Registered Senior Member

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    Good luck ordering from Amazon, John.

    Thank you both and good night.
     
  19. Buckaroo Banzai Mentat Registered Senior Member

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    ...

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    Sorry to disappoint, but not me yet...


    ...I do not see yet how the emergent properties affect gene-selection... :bugeye: and maybe mainly, what would be the great difference expected from gene to individual selecion, what each one would predict differently...

    but as I've said, I'm going to read more about these things
     
  20. Saith Registered Senior Member

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    A web exclusive from Discovery.com

    Granny Guards the Genes
    By Maia Weinstock
    April 15, 2004 | Biology & Medicine

    Not to sound crass—but why are so many postmenopausal women still alive? Most female mammals procreate until they die, but human women tend to live well past their reproductive years. Biologists Virpi Lummaa of the University of Sheffield in England and Mirkka Lahdenperä of the University of Turku in Finland find evidence that the added longevity may have evolved to help grandmothers protect their genetic legacy.

    The researchers pored over records of roughly 2,800 Canadian and Finnish women who lived between 1700 and 1900. The data show that for every 10 years a woman lived beyond age 50, she gained two grandchildren, on average. Lummaa ses this pattern as a reflection of the long period of nurturing that human offspring require. Children who lose their mothers at an early age are evidently less likely to survive to adulthood and start healthy families of their own. Recent studies of African tribes hint that nonreproductive grandmothers aid the expansion of the family by providing labor, emotional support, and life experience to their kin. “Old women can increase the reproductive success of their adult children in many ways if they survive long enough,” Lummaa says.
     
  21. spuriousmonkey Banned Banned

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    Did anyone study the opposite effect. Grandparents lowering the fitness of the offspring of none-relatives.


    It is known of course that domestic violence from step-parents is more often aimed at their step-children than at their own children.

    How about the grand parents?
     
  22. John Connellan Valued Senior Member

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    Well I haven't completely changed my mind yet either but as Paul and BigBlue said, I think I have to read some of those specialist books before I make my mind up!
     
  23. paulsamuel Registered Senior Member

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    Well, in the gene-selectionist view, although it is the phenotype that is selected upon directly, it is really the genes upon which selection acts, indirectly. However, for this to be true, and the gene-selectionists agree, then there has to be one gene-one trait for selection to act. One can't have one gene many traits, depending upon the genetic environment in which it resides. According to Gould, even the staunchist gene-selectionists (Dawkins and Williams) are now back-pedalling.
     

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