Darwinian Evolution Considered As a Phase

LucidBeast tips a mind-bending report at New Scientist on the latest paradigm-breaking work of Carl Woese, one of whose earlier discoveries was the third branch of life on Earth, the Archaea. Woese and physicist Nigel Goldenfeld argue that, even in its sophisticated modern form, Darwin's theory of evolution by natural selection applies only to a recent phase of life on Earth. Woese and Goldenfeld believe that horizontal evolution led to the rise of the genetic code itself. "At the root of this idea is overwhelming recent evidence for horizontal gene transfer — in which organisms acquire genetic material 'horizontally' from other organisms around them, rather than vertically from their parents or ancestors. The donor organisms may not even be the same species. This mechanism is already known to play a huge role in the evolution of microbial genomes, but its consequences have hardly been explored. According to Woese and Goldenfeld, they are profound, and horizontal gene transfer alters the evolutionary process itself."

Comments

Original paper on arXiv

[PaulBu]

For those who do not care to register for that New Scientist, we still have arXiv... :)

http://arxiv.org/abs/q-bio/0702015

Paul B.

Re:Here's A Tip, Folks

[icebike]

Horizontal gene transfer has been known about for decades, and the notion that the root of the tree of life is more a tangle of interconnecting branches has pretty much been accepted for some time now.

Further it has nothing at all to do with Darwinism.

A mechanism of gene transfer plays no role in the "Survival of the Fittest" (a phrase coined not by Darwin, but rather by Spencer), or natural selection. Its not germane.

Natural Selection is a winnowing process, and a mutation amplifying force, but says nothing about the acquisition or dispersion of said mutations. It was never meant to.

Re:Here's A Tip, Folks

[icebike]

I fail to see the point of confusion.

Acquisition of a trait (by whatever means) would never amount to a significant percentage of the gene pool of an organism unless it proffered some usefulness. Mutation or horizontal genetic transfer are but mere mechanisms. Darwinism discusses the overall process, not the details.

How that transfer took place is mere details. When that transfer takes place is not fixed in time. Horizontal transfer still exists in larger and more complex organisms and their symbiotic partners.

Re:Here's A Tip, Folks

[BrokenHalo]

I'm sorry, but I've never heard of this theory before, and I daresay I'm not the only one.

OK, here you go, then: Prokaryotes (i.e. bacteria, archea and so forth), by virtue of the comparatively "exposed" genetic material (not condensed or "bunched up" like ours typically is) and because of the structure of their cellular membranes, are very capable of "scraping up" any loose genetic material that may be lying around (e.g. as a result of cellular lysis). If these nucleic acids confer an evolutionary advantage, they are propagated in successive generations. This is why, and how "superbugs" like MRSA are thought to have evolved.

Microbiologists have used this feature for decades in the genetic engineering of bacteria to induce desired characteristics. The process is much harder and more complicated in eukaryotic (e.g. animal or plant) cells, but it can and does happen.