Rapid evolution or epigenetics? (Introduction)

by dhw, Thursday, March 03, 2011, 18:49 (5014 days ago) @ David Turell

I asked David if there were scientific objections to my suggestion that innovations might be powered by intelligent cells.-DAVID: Yes, objections. It seems as though you are picking my brain with knife and fork. Let's define what we are discussing. All cells have the same DNA, but cells are differentiated into unchanging cell types for the different organs in complex eukaryotes (CE). The only cells allowed by biochemical controls in that CE to further differentiate are adult stem cells, and they are meant for repair. Thus we are left with germ cells making sperm or egg. They can mutate or change epigenetically and then can carry forward some change in the CE, usually small. If somatic cells, those of the various organs, decide to change, what we see clinically is that now you are dealing with cells out of control and creating a cancer originating in the particular organ. -So our discussion is confined to germ cells, and they can change endogenously by epigenetic adaptation mechanisms, some of which I listed in my last entry, or exogenously by cosmic rays, or transcription errors, etc. It would be neat to satisfy our curiosity about macroevolution, by your fuzzy theories, but they won't work, based on the enumerated controls. We have not researched all 'junk' DNA, and as it is picked apart it reveals more and more code or control mechanisms. The 'drive to complexity' may turn up there if I am correct or DOC may be hidden in histones, around which DNA is carefully wrapped. We just don't know enough as yet. So we remain where we started: Darwin does describe microevolution, but has no answers for macroevolution. But neither do we, as yet, the skeptics.-My apologies for making a meal of your grey cells, but thank you for this comprehensive answer, the sting of which lies scorpion-like in the tail. It appears that no cells are capable of major beneficial innovations, but no-one can explain macroevolution. At least that puts me in good company! I agree with you that my suggestion ... I wouldn't dare call it a theory ... is fuzzy (nice word!) but is it any fuzzier than the proposition that an unknown and unknowable super-intelligence pre-programmed an as yet unknown mechanism to produce new organs and species?
 
However, you have a more concrete proposition, if I've understood you correctly: the innovative mechanism lies in 'junk' DNA, or possibly in histones, and presumably in the germ cells, which makes perfect sense anyway, since an existing creature is hardly likely suddenly to sprout a new organ. Initially in your post you confine the endogenous changes to epigenetic adaptation (and suggest that exogenous changes are deleterious?) though even this can imply a form of intelligence. Many organisms fail to adapt, so in those that do, there is some sort of superiority inherent in the mechanism. But ... if my interpretation is correct ... you also believe that this same mechanism is pre-programmed to produce innovations when conditions are right. So please indulge me in my fuzziness, my ignorance, and also my repetitiveness, and let me ask again: what would be the difference in procedure and outcome between, on the one hand, a UI pre-programming a mechanism within the germ cells to produce the innovations and, on the other, the same mechanism responding to the right conditions and producing the innovations on its own intelligent, inventive initiative?