The three primary divisions of life now comprise the familiar bacteria and eukaryotes, along with the Archaea. Woese argues that these three life forms evolved separately but exchanged genes, which he refers to as inventions, along the way. He rejects the widely held notion that endosymbiosis (which led to chloroplasts and mitochondria) was the driving force in the evolution of the eukaryotic cell itself or that it was a determining factor in cellular evolution, because that approach assumes a beginning with fully evolved cells.I would have guessed that truly separately-evolved (no common descent) organisms couldn't really do lateral transfer with any hope of compatibility. I gather that the soup takes the place of the usual common ancestor in this case. Same soup, three lines of "offspring," lateral transfer works.
Woese doesn't address the point, unfortunately. Nor does he explain here what his theory does better, or even differently. What are the consequences, the tests?
Same RNA world, different lines of descent to the point where Darwinian evolution becomes a viable way of resolving ancestry.
Woese presents what he calls "A theory for the evolution of cellular organization." The root of the universal tree does not begin at the origin of life, it "has no root in the classical sense", but rather at the Darwinian Threshold, the point at which a level of cellular organization emerges when horizontal gene transfer is no longer the predominant form of novelty generation. It is at this point that vertically generated novelty assumes greater importance and one can speak of Darwinian evolution.
The time-line between the RNA world and modern cellular organization is a long one and includes the evolution of translation. Crossing the threshold happened at different times for the separately evolved organisms. There is ample evidence for this from molecular data. Bacteria crossed this threshold first. "The bacterial versions of the central (universal) cellular systems respresent earlier ancestral versions of these systems than do their archael or eukaryotic counterparts." Darwinian evolution predicts that genes should be shared more as you move to the bottom of the universal tree until one can predict a common ancestor which contains all the genes. Instead, there are gene families not common to the various prokaryotic and eukaryotic cells.
Woese doesn't address the point, unfortunately [compatible lineages]. Nor does he explain here what his theory does better, or even differently. What are the consequences, the tests?
The consequenses are an explanation for the molecular problems at the root of the tree. This explanation goes a long way toward explaining cellular evolution and the origin of the known different lineages at the root of the universal tree.