Biological complexity: phase separation (Introduction)

by dhw, Wednesday, November 09, 2022, 12:17 (745 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?
[…]
DAVID: Of course, a science article cannot allow God to put His toe in. Those molecules somehow know exactly what to do in the soup.

Yes, they do. And I don’t know why a theist shouldn’t accept the possibility that his all-powerful God, who has endowed humans with the intelligence to organize their own forms of cooperation etc., might endow micro-organisms with the intelligence to organize THEIR forms of cooperation.

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

dhw: 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!”

DAVID: That is a brilliant opossum who was able to conceptualize the trick on his own.

Two tiny tales for you:

One day, Pete Opossum spied a dead opossum in the distance. A predator approached the dead body, took one look, said “Yuk!” and walked away. The next day, Pete saw a predator before it saw him. There was no escape route. It meant certain death, unless...maybe you can guess the rest.

One day God, who has the whole world (even universe) to watch over, spotted Pete Opossum and a predator in the wilds of North America. As for some unknown reason Pete’s individual survival was crucial to God’s plan for all humans and their ecosystems, he whispered in fluent Opossumese: “Lie down, Pete, and pretend you’re dead.” And Pete did lie down, and thus he was saved.

I wonder which of these tales tickles your fancy.

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.

dhw: 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?

DAVID: Thank you for finally recognizing the difference. They signal with molecules they are built to sense.

“Finally”? When have I ever claimed that bacteria etc. were as intelligent as humans??? Back to the subject: bacteria signal, and they respond to signals, using the communication mechanisms at their disposal, just as we do. The question is how they decide on the correct interpretation of signals they receive, and how they decide on what messages to send. You only want to focus on the signalling and gloss over the whole process of decision-making.