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Close biological analogs of money?

  1. Jul 5, 2015 #1
    With all a biological organism has to do in the way of allocating limited resources among lots of different parts that need them in a timely manner, I'm wondering if there are biological chemicals that are closely analogous to money.

    I've heard ATP referred to as the common currency of metabolism. I can sort of see that. It has the role of an intermediary, which is sort of like a medium of exchange. But doesn't it continuously get consumed and regenerated? That makes me associate it more with a staple food. Like in a primitive economy where agricultural workers are paid in grain so that they can have energy to produce more grain.

    Then there are enzymes. Money functions much like a catalyst for exchanges where both sides profit (these are energetically favorable reactions). Without money, these favorable exchanges would take much longer to happen. You have to find someone to barter with. But money lowers the informational barriers to exchange.

    The difference is, enzymes don't seem to be possessed by any particular reactant (or is this wrong?), whereas money actually changes hands for exchanges to happen. It is a medium of exchange.

    Are there more, or perhaps better, analogies between biological organization and the price system? Or are they more different than similar?

  2. jcsd
  3. Jul 5, 2015 #2


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    Not really no, "energy currency" is an imperfect analogy. Resources in the body aren't traded in any way that is similar to market forces, nutrients are cycled through the circulatory system and absorbed by the tissues that need them. When there aren't enough nutrients reaching tissues they can release signalling factors to encourage release/production from elsewhere.
  4. Jul 5, 2015 #3
    Idealistic socialism would seem to be a closer analogy than a market driven economy.
    (Not a political statement, it just seems like a closer analogy to me.)
  5. Jul 5, 2015 #4
    OK, so the market isn't such a great analogy. Still, I can get something even from imperfect analogies. The market might be a specific example of a more general principle of organization. Which I need to find.

    That is awesome. I am very interested in self-organizing systems. I guess price signals are just one way of achieving practically the same thing.

    I assume there are also control mechanisms to keep any particular tissue from being too greedy, signalling for and absorbing nutrients that could be put to better use elsewhere? Or is it that when the nutrient starts circulating, whatever tissue needs it the most will absorb it the fastest.
  6. Jul 5, 2015 #5


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    You can look up "homeostasis". Diabetes is an example of a disease which can be thought of as a failure of glucose homeostasis.

    There is also homeostatic control of blood flow.
    Last edited: Jul 5, 2015
  7. Jul 6, 2015 #6
    Thank you! I have been trying to psych myself up to learn the nuts and bolts of feedback control theory, and that model for glucose regulation is exactly the type of motivation I need to get into it. It also served as a useful reminder to put the books down once in a while and get some exercise so the muscles don't forget how to dispose of glucose. And to keep the beer belly in check. Perhaps a switch to Bud Light is indicated. :)

    I like Bergman's understanding of how science works. New understanding is always schematic in nature. You can always fill in details later as needed, but to gain new knowledge, you have to have a simplified model that cuts to the chase.
  8. Jul 6, 2015 #7


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    Actually, I meant to put something simpler than Bergman's article, but unknowingly did something that switched the links!

    Anyway, knock yourself out if you'd like to learn feedback control on the glucose regulation system! I'd love to understand it one day too. You may find Astrom and Murray's text http://www.cds.caltech.edu/~murray/amwiki/index.php/Main_Page useful. There's a very brief discussion of the work by Bergman and others in section 3.6 of the first edition or Appendix A.6 of the draft second edition http://www.cds.caltech.edu/~murray/books/AM08/pdf/fbs-examples_22Jun14.pdf.
  9. Jul 7, 2015 #8
    It worked out for the best. I was able to piece together what truncal adiposity meant from the context. You can bet I will try to work that into a conversation.

    Excellent. Thanks!

    Of course I'll have to start out easy, with bimetallic strip thermostats and all that. But ultimately I want to understand those feedback control systems whose design coincided with their implementation. Nature just makes stuff up as it goes.
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