Scoop Feedback: David Deamer Re Interview w/ NASA's Chris McKay
I agree with Chris [NASA Humanist Chris Mckay: Where Darwinism Fails] that it can't be "Darwinism all the way down..."
The scenario I consider to be most plausible is that life arose from molecular assemblages that happened to have a certain set of properties we now associate with life: capture of energy and nutrients in order to undergo growth by polymerization reactions, followed by reproduction.
The microscopic systems, basically primitive cell-like structures, were embedded in vast numbers of similar but not identical assemblages, most of which were inert, but a few having these properties to varying degrees. At first there was no competition in the usual sense, and the only selective factor involved was the efficiency at which growth and reproduction could occur, which would have been very slow by today's standards. But at some point the more successful molecular systems began to get pretty good at filling niches, and the resources available became limiting.
Other selective forces came into play, and I would suggest that what we now call evolution began at that point, when different varieties of microorganisms started to interact and compete for nutrients. I doubt that Darwin would have called this process Darwinian, even if he did know about genes, mutations and DNA, because the microbial varieties were constantly mixing their genomes by horizontal gene transfer, so there was no tree-like lineage.
Over a billion years ago, eukaryotic cells arose by a chance symbiosis between microbial populations. At that point specific genomes began to be associated with the multicellular organisms we now categorize as species which can be organized into phylogenetic trees.
David W. Deamer
Professor Emeritus of Chemistry
University of California - Santa Cruz