Biological complexity: phase separation (Introduction)

by dhw, Tuesday, November 08, 2022, 09:26 (747 days ago) @ David Turell

QUOTE: How do the right proteins organize themselves in a sea of fluid swarming with millions of molecules? Do they bump into each other by chance, or does the cell actively organize its fluid space to bring the correct partners together?

dhw: Thank you for this. It’s almost impossible for us large organisms to get our heads round the fact that this unit of life – so tiny that we can’t even see it with the naked eye - is itself an immensely complex community of interactive parts. There is no way the organization can be left to chance, and the author offers only one alternative: cells actively organizing themselves. And if they do this individually, they will also do it collectively in the cell communities that cooperate to form organs and organisms, as well as to make the changes that respond to new circumstances and result in new species. Human societies self-organize in the same way, and we would laugh at the idea that they run automatically (see “quorum sensing” below). Our communities are organized by their own intelligence, no matter what may have been the original source of that intelligence. And so if cells self-organize as we do, and their communities self-organize as our communities do, is it not logical to argue that their self-organization is run by their intelligence, just as ours is?

DAVID: It is also just as logical to see a designed arrangement running on instructions given by God is His designing efforts.

On the surface, it may seem so, but the idea that 3.8 thousand million years ago your God supplied the first cells with instructions to be passed on for the creation of every new organ and organism and every decision for every new set of problems for every new combination of cells suddenly makes the theory a little less convincing for me, as does the theory that he is on hand all over the planet to provide organisms with the solutions to their problems of survival as and when the problems arise. Just imagine him spotting that poor old opossum in the depths of the forest and whispering in its ear: “Lie down and pretend you’re dead!”

Quorum sensing: how it works in bacteria and viruses

DAVID: obviously both bacteria and viruses have receptors for these specific signaling molecules and built-in automatic responses to the levels involved.

dhw: As usual you shove in the word “automatic” but the process described above is the equivalent of describing all the physical processes by which we humans communicate and act once we have taken a mental decision on what to do. Yes, if I decide to talk to you, I will activate all kinds of chemicals and tissues and muscles and electrical impulses. But they are all the consequences of what is NOT automatic: namely the decision to talk to you. Bacteria and viruses must decide on the best course of action before they set in motion the physical processes that will implement their decisions.

DAVID: As usual you elevate bacteria, viruses and single cells to the human thought level.

A silly exaggeration. Do you really think I’m arguing that bacteria, viruses and cells philosophize, design rockets to the moon, write novels and symphonies, and conduct forums discussing the existence of God and of cellular intelligence?