by Ed Yong Nov 18, 2013
Excerpt: “Bacteria can feed on bits of DNA from their surroundings. They can also incorporate these fragments into their own genome, as easily as you might put a new book onto your shelf. These horizontal gene transfers give bacteria an edge in the evolutionary race.”
Excerpt 2: “He calls it anachronistic evolution. “It’s something we’ve not considered before and it’s not in our models of microbe evolution.””
My comment: See Kohl (2012) Human pheromones and food odors: epigenetic influences on the socioaffective nature of evolved behaviors
Among different bacterial species existing in similar environments, DNA uptake (Palchevskiy & Finkel, 2009) appears to have epigenetically ‘fed’ interspecies methylation and speciation via conjugation (Fall et al., 2007; Finkel & Kolter, 2001; Friso & Choi, 2002). This indicates that reproduction began with an active nutrient uptake mechanism in heterospecifics and that the mechanism evolved to become symbiogenesis in the conspecifics of asexual organisms (Margulis, 1998).”
This “anachronistic evolution” started somewhere, but I don’t know how it could have started outside the context of a living cell that could ingest the DNA from a cell that died. This appears to present yet another dilemma for theoretical biologists who want to remove the laws of physics from biologically based evolution.
See for example: Evolution of transcriptional enhancers and animal diversity: “Each of these papers, in one way or another, consolidates the idea that there will probably be no fixed law, like gravity, to explain at the molecular level how endless forms most beautiful and most wonderful have been, and are being evolved. It rather seems that a wide variety of peculiar molecular mechanisms perform, together, the complex task of putting the genome in action, in each cell type of each animal species, at every moment in life and under every possible physiological and environmental circumstance.”
My comment: No fixed law, such as gravity, infers no fixed law such as the Second Law of Thermodynamics. Clearly, if you dispense with the concept of “entropy” the structure of DNA can automagically exist inside or outside cells and outside the context of organismal complexity. With the magic of theory, the DNA of ever-more complex organized genomes simply self-organizes itself after the cell that automagically evolved ingests DNA from a cell that died.