Evolution (Introduction)

by dhw, Sunday, April 19, 2009, 20:35 (5492 days ago) @ George Jelliss

George: The code at that stage [the first simple forms of life] enables replication, it does not enable adaptation, that follows by the process of natural selection. - George: The first replicating molecules would only produce very similar replicating molecules. Complexity appears gradually over time by natural selection. - But natural selection is not creative. It doesn't "enable" adaptation or cause complexity. Natural selection is the process by which existing variations survive or disappear because they are or are not advantageous. It doesn't matter whether it's the second or the millionth generation of replicating molecules that began to produce variations, natural selection can only "kick in" when there is something to select from. This principle applies whether the variations are caused by random combinations (complexity) or the impact of the environment (adaptability) or accidental mutations. The problem is not natural selection but the origin of the capability for variation. - You, David and I (but I do wish others would join in) seem to agree that life began with replicating molecules, and I'm sure we agree that so far we humans represent a pinnacle of complexity. During the evolution from mindless, unconscious blobs to us, the variations over billions of years have created arms, legs, eyes, ears, digestive systems, penises, vaginas, memory, consciousness etc. etc. It all seems incredible, but evolution is the best explanation we have: variations which survive and improve through natural selection. However, if there is an unbroken line from blobs to us, it can only be because those blobs contained the potential capability or "code" for such variation. If they had only been capable of replication, there would have been no evolution. In other words, the code for life and replication must have included the code for creative variation ("creative" because it led to hitherto non-existent, functioning organisms). This code is so intricate that we still haven't unravelled it, and if it's too complex for the most brilliant minds of our time to unravel, then it's too complex for me to attribute it with any confidence to a stroke of luck. And that is why I cannot share your faith in the theory of abiogenesis. - By the first replicating molecules and its "mates" I meant buddies, chums, pals, and not concubines! Thank you for drawing my attention to the ambiguity. I've taken the liberty of editing it out.