How epigenetics works (Introduction)

by dhw, Thursday, January 10, 2013, 19:58 (4125 days ago) @ David Turell

DAVID: Since we really still don't know how species originate, your proposals are valid up to a point. [...] The genome adapts with epigenetic changes, but the steps to a new species are not clear. Not to me at least. Epigenetics plays a major role, but it is not clear how inheritable those adaptations are.-I must admit, there is no way of knowing whether God steps in at appropriate moments or whether the uncalled-for advances, multicellularity, the big brain, etc. are pre-programmed. Since our arrival on the scene with our consciousness is uncalled for, the best guess is that it is all pre-programmed.-The one thing that is clear from your post is that nothing is clear, and I'm more than happy to settle for my proposal being "valid up to a point". The same qualification has to apply to all proposals. I'd like to round this off with a summary of the ramifications of my own, which is that new organs and organisms are the result of an intelligent mechanism within the genome that invents new cell combinations as and when the environment allows them. (Intelligence = the ability of living organisms to learn, understand, remember, process and use information.) Natural selection decides which of these inventions will survive. My starting point is the belief that all forms of life are descended from earlier forms, going back to Darwin's original few forms or one.-Alternatives: 1) innovations are the result of an endless series of random but functional mutations; 2) a god directly created every innovation; 3) a god preprogrammed every innovation into the earliest form(s) of life. -From an evolutionary standpoint, the intelligent genome explains not only how innovations take place, but also why the history of evolution has developed into a higgledy-piggledy bush, as changing environments result in extinctions and innovations (while some existing species survive because there is also a mechanism ... possibly the same one ... that enables adaptation). Any major change in the environment could result in a massive increase in innovations (possible explanation for the Cambrian Explosion).-From an atheist standpoint, this has the advantage of entirely removing reliance on Darwin's random mutations, so that evolution itself becomes a naturally creative process dependent solely on interaction between living organisms and a changing environment. It has the disadvantage that the so-called "simple" forms of life must have incorporated this inventive intelligence from the beginning in a mechanism so complex that the odds against its chance assembly become incalculable. -From a theist standpoint, the latter is the most obvious advantage. However, the above scenario runs counter to the anthropocentric interpretation of evolution, because of its higgledy-piggledy progress, unless God found his plans going awry and needed to intervene "at appropriate moments" (goodbye to omniscience and omnipotence). The bush resulting from the interplay between the mechanism and the changing environment also favours the version of deism which makes God the creator of the "intelligent genome", who then sits back and watches evolution run its course without intervention. Alternatives: 1) God set up the mechanism without any particular aim, but tinkered with it as he became aware of its possibilities (out goes omniscience again); 2) human reason cannot fathom the workings of God's mind, and we should abandon it ... unless...um...it leads us to have faith in him.