Wednesday, August 21, 2019

Locality: life's Newtonian equivalent of 'universality'

In, 1687, in his groundbreaking Principia, Isaac Newton made a fundamental assertion--a fundamental assumption--about reality.  It is that whatever you observe in some location, such as your lab, will apply everywhere else in the cosmos.  He was talking about the nature of the physical universe, following similar views of Galileo, who quipped that the laws of nature were written in the language of mathematics.

Paperback Philosophiae Naturalis Principia Mathematica Book

If the universe was God's creation, its vastness would be of a kind, similar everywhere.  That notion is what stands behind the idea of universal 'laws' of Nature.  The 'laws' were not passed by an Angelic Congress, but are simply God's way of organizing physical existence--all of it!

These laws, discovered by classical physics, are deterministic and universal, not probabilistic, not haphazard.  I don't recall anything about what Newton thought of probabilities other than a debate with Pepys about gambling, but that was not central to his cosmic worldview, which was essentially deterministic--which is what you might expect from an all-knowing God.

But subsequent science has revealed at least two key additions.  First, some of Nature seems inherently probabilistic.  Here we are not restricted to measurement issues, because probabilities seem inherent in quantum-level phenomena.   Secondly,  probabilism means that conditions are at least to some extent contingent on what did happen, relative to what might have happened.  This means that predictions can only be probabilistic at some scale; whether that means the cosmos' states and future are unknowable or not is not for someone like me to opine about!  Whether the probability values are, somehow, fixed, and if so how that is, are interesting and, I think, important questions.

Life is part of the universe, but its fundamental laws are of locality, not universality
Life is a chemical and hence physical phenomenon.  But life in the deeper sense is about how these molecules are organized, and this seems fundamentally different from the kind of molecular evolution seen in stars.  Each star seems, from what one reads, to be similar at the chemical or atomic/subatomic level.

But life evolves by local conditions.  Mutations arise locally and are filtered by selection and chance locally.  Successful mutations and genotypes spread by migration from their source, but are then always subject to genetic and environmental conditions in their new localities.

Locality also is the central fact or organismal organ and system diversity.  In this case, it is local conditions determining gene activation and expression.

But, in a sense prisoners of 19th century physics success, the long shadow of Newton and Galileo, we seem to hunger for laws of life that apply, as the slogan goes, to 'All of us' and that leads to genomic medicine that we are told can be known with some kind of presumably universal 'precision'.  These are, to me, irresponsible misrepresentations made by Francis Collins and NIH, perhaps as their strategy to pry mega-bucks from Congress--because they are naive relative to the biology they promise to understand.

But if we overlook the truth and live in slogans, does this undermine the very science we want to nurture?  The assumption of universality, to me, is fundamentally misleading about how life works and how our genotypes got here.  Whether or how we can use this understanding to develop appropriate medications and so on, is a separate set of very important questions, about which I'm not capable of making judgments....


Steven B Kurtz said...

Hi Ken,

I have occasionally quibbled with your posts, but not this one. Living systems are different than non-living ones. Multi-generational heredity (biome, epigenes, viruses, prions, ...?) plus experiences since conception or other "beginning" event, combine to form a multitude of possible feedback loops through internal filters. Even cloning isn't always 100% identical (from what I've read), as radiation and other variables are tough to control.

Steven Kurtz
retired dilettante
Amherst MA

Ken Weiss said...

Yes, tough to identify much less control. And with many ways to similar ends, prediction is problematic (and not with 'precision' based on genomes). What is predictable is the way major funding is locked up indefinitely for the juicy catch-word fad Big Data (as well as everything-'Omics)