In Kohl (2012) I wrote:
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).
Now Elizabeth Howell, Astrobiology Magazine Date: asks
Excerpt: “…you have almost a molecular ecology,” Fellermann said. “Every species and strand, they service each other’s reactants and products and catalysts.”
My comment: I have since added more details about how symbiogenesis how every species interacts. I’ve placed the details into the context of the molecular ecology in an invited review of nutritional epigenetics. The review is based on the molecular epigenetics section in our 1996 Hormones and Behavior review and other published works.
See: Nutrient-dependent pheromone-controlled ecological adaptations: from atoms to ecosystems
Instead, I build from examples of biologically-based cause and effect. The examples link nutrient-dependent amino acid substitutions, which are are fixed in the DNA of organized genomes via the physiology of reproduction. Other examples were included in Nutrient-dependent/pheromone-controlled adaptive evolution: a model
A recent report links light-induced amino acid substitutions from plants to unicelluar algae and to a multicellular sea slug. FISH Labeling Reveals a Horizontally Transferred Algal (Vaucheria litorea) Nuclear Gene on a Sea Slug (Elysia chlorotica) Chromosome
That makes it easier to link microRNAs from crustaceans to insects via the conserved molecular mechanisms we detailed in 1996 that linked insects to mammals, including primates. Dobzhansky (1973) also linked amino acid substitutions to cell type differentiation. “…the so-called alpha chains of hemoglobin have identical sequences of amino acids in man and the chimpanzee, but they differ in a single amino acid (out of 141) in the gorilla.”
The conserved molecular mechanisms of RNA-directed DNA methylation and RNA-mediated amino acid substitutions that differentiate cell types are now perfectly clear to anyone who has not continued to ignore what Dobzhansky knew 50 years ago. In “Biology, molecular and organismic” he wrote: “the only worthwhile biology is molecular biology. All else is “bird watching” or “butterfly collecting.” Bird watching and butterfly collecting are occupations manifestly unworthy of serious scientists!”