Bit of an essay this i'm afraid...
You can think of hsp90 as a molecular handbrake.
DNA codes for proteins, nothing else, there's all kinds of groovy machinery to make sure everything gets copied correctly through a couple of systems until it gets made into protein. Once the building blocks of the protein are assembled in the right order (primary structure), they've got to then fold on themselves into 3-d (secondary structure), and interact with other block-chains (tertiary structure) to form the working protein.
The primary structure/sequence of blocks is pretty key to how they fold, but there's an element of chance, of trial and error folding, based on non-linear dynamics (chaos . Stuff like hsp90/70 (called chaperones) increases the probability that they'll fold correctly, and not get stuck down a dead end, misfold, and stick together (which'll kill the cell). Some hold proteins at a particular point til the chaperone's activated, and then they allow their helpee protein to fold and activate. They're all about timing basically, think of them as counterbalances and springs in an old clock.
During times when the cell/organism is stressed (that's where they got their name 'Heat Shock Protein - HSP), hsps are in short supply. Other key proteins start unfolding as proteins misfold if there's loads of salt/heat/cold around and hsp90 starts to leave some of it's regular proteins and go and help out elsewhere, leaving it's regular, possibly mutated proteins to activate weird and wonderful pathways. HSP's also a protein itself, and as it's concerned with cell division, and acting as a relay for x-hundred other things that communicate with hundreds of other things in the cell and outside the cell. So it's really feckin complicated.
There's a bit of work that's been done in plants, with pretty much the same results as the fruit fly you mentioned...lots of physical changes occur when you block the copying of hsp90 from DNA to protein, or when you stress the plants with heat.
So, all this is showing is that Hsp90 might be able to soak up the effects of different genes and mutations when everything in the environment's as normal, whilst allowing the variation/mutation/evolution to kick in when stress occurs. Basically you could see it as a panic button "we're fucked if we don't change soon", press the hsp90 button - mutate away, and hopefully one or more 'll work.
So, as far as I understand what you're saying, I reckon it's applicable to what you're talking about, mutations (in gene, meme, or whatever) are stored until the brakes (hsp, circumstances, ideas) are removed by stressful conditions, (or meditation, or psychedelics, what have you), is that about it? The thing about doing the work in flies, is that their life cycles are so short you can see the effects, if you can run with the thoughts or behaviour, and shorten your own loop, then yep, good system
Lucky, yep, you're right, evolution as we understand it (which may or may not be true) is totally random, and ask a Darwinian about the idea that something's driving us to some ideal form or supercontextualwooyayintegration, hopefully in the next 7 years, and they'll laugh in your face. There are genetic changes, some of these are great, give us an advantage, and we call that evolution. Some of them fuck us over, and you couldn't call that evolution (in the linear, aiming for something sense), even though it's the same process. I mean it's possible we'll all become energy-beings, forever mooching around the universe like an incandescent fart, but it's just as possible that we'll all become blue tiger-person-ninjas with whirring nunchaku tails of death. Which'll be nice. |