Biology’s next revolution
by Nigel Goldenfeld and Carl Woese
Nature 445, 369 (25 January 2007)
The emerging picture of microbes as gene-swapping collectives demands a revision of such concepts as organism, species and evolution itself.
Equally exciting is the realization that viruses have a fundamental role in the biosphere, in both immediate and long-term evolutionary senses. Recent work suggests that viruses are an important repository and memory of a community’s genetic information, contributing to the system’s evolutionary dynamics and stability. This is hinted at, for example, by prophage induction, in which viruses latent in cells can become activated by environmental influences. The ensuing destruction of the cell and viral replication is a potent mechanism for the dispersal of host and viral genes.
It is becoming clear that microorganisms have a remarkable ability to reconstruct their genomes in the face of dire environmental stresses, and that in some cases their collective interactions with viruses may be crucial to this. In such a situation, how valid is the very concept of an organism in isolation? It seems that there is a continuity of energy flux and informational transfer from the genome up through cells, community, virosphere and environment. We would go so far as to suggest that a defining characteristic of life is the strong dependency on flux from the environment Ã¢â‚¬â€ be it of energy, chemicals, metabolites or genes.
Horizontal gene transfer and community repositories of complex specified genetic information… these are things that fit really well with the front loading hypothesis. HGT and community gene libraries triggered by environmental cues are plausible mechanisms for preplanned evolution via saltation.
Read the rest of the Nature essay at the link above. I also recommend the science fiction book “Darwin’s Radio” by Greg Bear as it incorporates into the plot many of the HGT concepts discussed in the Nature article. As a matter of fact “Darwin’s Radio” was very favorably reviewed in Nature some years ago by accomplished geneticist Professor Michael A. Goldman. “Darwin’s Radio” is what rekindled my interest in ID. Bear doesn’t really support ID but he does a fair job of bringing into serious question the orthodox beliefs about gradualistic macroevolution. If orthodox beliefs are wrong one wonders what’s right and ID inevitably pops up as a possibility to any unbiased inquirer.