In his book Biology of Aging, Roger McDonald describes the difference between causes and mechanisms of aging; and states that the cause of aging is essentially thermodynamic (entropy) and that mechanisms can be divided in distal and proximal.

The scientific and lay literature describing biological aging can be confusing due to the misuse of the words cause and mechanism. Often these two terms are used interchangeably, although they have different meanings in the context of aging

The cause of aging refers to the thermodynamic forces that act continually on the organism throughout its life span. There exists only one cause of aging: increasing entropy.

Alterations in the biomolecules that lead to loss of function are the mechanisms of aging. There exist an infinite number of mechanisms that can be observed [...] We also distinguish between two types of aging mechanisms: distal and proximal

then defines distal mechanism of aging as

A mechanisms of aging that underlies and is remote from the more obvious direct cause for a time-dependent functional loss. For example, obesity is the distal cause of abnormally high blood glucose concentration. Abnormally high blood glucose concentration results in the time-dependent functional loss of connective tissue due to advanced glycation end products

and proximal mechanism of aging as

A time-dependent alteration to a tissue, cell, or molecular process that lead to a loss in function

personally this seems something that he believes and in that sense not very precise academically or scientifically, because I can't find any reference regarding the subject

my question regards the following, is this information something that he believes in or does it has a foundation in biogerontology? and if the latter, can somebody kindly reference the subject with an article?

  • $\begingroup$ Thanks for replacing with text; it seems like if your question is about "proximal/distal" mechanisms, that you've included a bunch of unrelated text about "cause vs mechanism" and then stopped quoting where the section about "distal and proximal" is to begin. $\endgroup$
    – Bryan Krause
    Feb 11, 2022 at 15:56
  • $\begingroup$ my fundamental question is in fact about proximal/distal mechanisms but the cause/mechanism distinction also worries me, because it is the first time i'm reading it and i have no reference that proves that this is true or unanimous among biogerontologists.. however my priority is the distal/proximal mechanism $\endgroup$
    – program
    Feb 11, 2022 at 16:17
  • $\begingroup$ It's not uncommon to see an author provide some working definitions to keep readers from getting confused, because biologists don't typically sit everyone down to formally agree on universal definitions for every term in a given field of study. While the first point about cause vs. mechanism is a bit reductive and pedantic (imho), the fact that he even points it out suggests that it's not universally accepted in the literature. The proximal/distal distinction is probably just a useful framework for thinking about mechanisms that he will likely refer back to throughout the text. $\endgroup$
    – MikeyC
    Feb 11, 2022 at 18:19
  • 1
    $\begingroup$ thank you all for your contribution in this question; yes, it is likely that i'll choose that path, regarding this subject as a useful framework than a dogmatic definition.. i had the opportunity to read Ernst Mayr’s ‘‘Cause and Effect in Biology’’ where he presents the duality proximate/ultimate which is the most similar i can find in biology, beyond that i can only find related topics with sociology precisely about proximal/distal causes.. and that is another thing they say proximal/distal causes not mechanisms. thank you all again; @MikeyC feel free to write and answer if you'd like $\endgroup$
    – program
    Feb 11, 2022 at 18:45


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