Life as Evolving Software... (Chaitin) (Humans)

by dhw, Tuesday, December 27, 2011, 08:11 (4714 days ago) @ xeno6696

Matt, I’m going to cherrypick quotes from your posts, because together they show what I think is the basis of the misunderstanding between yourself on the one hand, and David and me on the other.

MATT: The main sticking point between David and I (and possibly yourself) is the challenge that the process of normal genetic transfer is not sufficient for speciation.

Normal genetic transfer would lead to perpetuation of the species. The problem is change, not replication. Darwin attributes change to random mutations and adaptations. But that’s not the main sticking point between us.

MATT: As for the explosions in the fossil record--we can only make claims on what we witness. If you combine our knowledge of how genetic information is passed on, with the fossil record--there is only one reasonable conclusion--given the evidence at hand. Evolution can speed up and slow down its processes given demand.

“MATT: In summary: I can't see beyond a G1-->G2 transmission of information being a key driver for observed changes in the fossil record. I identify this process as synonymous to gradualism, and therefore cannot step down the same path as David and yourself.

And this is the source of the misunderstanding. I hate to say it, but once again we have a problem of terminology. Gradualism, as I understand it, is not the flow of genetic information from generation to generation, but the theory that (a) complex organs evolved in tiny stages rather than by single mutations (Darwin says: “If it could be demonstrated that any complex organ existed which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down." (Origin, p. 214), and (b) evolution proceeds at a relatively constant rate – Dawkins talks of a “continuous and shallow slope up Mount Improbable” (God Delusion, p. 124). You yourself have acknowledged that there are sudden explosions of evolutionary creativity. These may be connected to environmental changes. Gradualism does not allow for such upheavals, and so far we cannot account for the sudden proliferation of new species at certain times (and new means really new, not just old species adapting). Epigenetics MAY supply us with an explanation of the mechanisms that allow not only adaptation but also innovation in response to environmental pressures. Changes therefore do occur from G1 to G2, but what you call “speeding up and slowing down” is what David and I understand by punctuated equilibrium (as opposed to gradualism), i.e. periods of comparative stasis interspersed with great activity. Nobody yet knows for sure how or why this happens – hence what you rightly call “conjectures”.

To sum up, the confusion here arises because you have a different definition of gradualism from that used by David and myself. You appear to accept the theory of punctuated equilibrium (i.e. there is no “real difference between evolution that ‘speeds up’ and PE”), and so there is no disagreement. Epigenetics is being discussed as a possible mechanism for rapid evolution. David’s pre-planning theory is another conjecture.