Miscellany (General)

by dhw, Monday, June 28, 2021, 13:43 (1034 days ago) @ David Turell

Most of this thread was taken over by discussions about a possible God’s possible purpose and nature, so I’ve transferred all of that to the appropriate section.

Plants response to heat stress
QUOTES: "Researchers have found that plants adapt to heat stress via a specific 'memory' mechanism. The JUMONJI family of proteins can control small heat shock genes, allowing plants to become heat tolerant for better adaptation to future heat stress.
"Heat stress is often repeating and changing," says lead author of the study Nobutoshi Yamaguchi. "Once plants have undergone mild heat stress, they become tolerant and can adapt to further heat stress. This is referred to as heat stress 'memory' and has been reported to be correlated to epigenetic modifications." Epigenetic modifications are inheritable changes in the way genes are expressed, and do not involve changes in the underlying DNA sequences.
"We wanted to discover how plants retain a memory of environmental changes."

DAVID: These plants are not thinking. Climbing heat makes them demethylate DNA and tolerate the heat. JUMONJ2 is an enzyme, which means a giant specialized molecule that must have been designed for the task.

I would never suggest that plants “think” in the same way as humans think. But that does not mean plants are not sentient, cognitive forms of life, and just as our immune system has evolved over millions of years from the rudimentary immune systems of other life forms to its current complexity, plants' resistance to heat goes back to the fact that in every organism you can think of, including ourselves, the cells must find means of adjusting to new conditions, or they and the whole organism will die. I agree that each adjustment must have been designed for the task. But nobody knows how. You offer us two possible explanations: 1) 3.8 thousand million years ago, your God provided the very first cells with a complete computer programme for the evolution of every single future organism plus every single adaptation that every organism would make throughout the future of life on Earth. Alternatively, he just kept on dabbling to design every new organism (although actually he only wanted to design us plus lunch), as well as to solve every new problem whenever it arose. A theistic alternative to these two theories is that he endowed the first cells with a mechanism of almost infinite flexibility that would enable some organisms to adapt to or exploit new conditions, using their intelligence to work out suitable ways of using that mechanism. If the cells couldn’t cope, then of course the organism became extinct. I remain baffled by your firm embrace of the first two, and your outright rejection of the third.