Genomic analysis of a key innovation in an experimental Escherichia coli population (subscription required).
This article details the three step process by which epigenetic “…potentiation makes a trait possible, actualization makes the trait be manifested, and refinement makes the trait effective…” The details are placed in the context of sensory cause and effect that is “…probably typical of many new functions.” The ability to use citrate as a new source of energy is exemplified. That ability is often reported to be due to mutations, although it is now believed by some people that a series of mutations is required. Others recognize that a series of mutations in not likely to be the cause of adaptive evolution, since most mutations are deleterious or have minimal effects on species survival.
Some people will recognize sensory cause and effect as the means by which the epigenetic landscape (i.e., the potentiation) becomes the physical landscape (i.e., the actualization) through chromatin remodeling and de novo gene expression linked to learning and memory and nutrient chemical uptake at the cellular level (i.e., refinement). Refinement also occurs at the organism level via the foundations of primary and secondary-process learning and memory mechanisms, which in humans interface with tertiary-process cognitive-thoughtful functions and behavior. However, that explanation is much more complicated than attributing evolution of our brain and behavior to a mutation or a series of mutations
The difference in humans compared to other organisms that cannot think about mutations or models for adaptive evolution is that we sometimes think about the epigenetic effects of food odors and pheromones on hormones and behavior in other species. Nevertheless, we rarely acknowledge that the molecular mechanisms of our behavior are the same as are found in every other species. If the epigenetic effects of food odors and pheromones did not alter the hormones that organize and activate our learning, memory, and behavior, we would have no more of an idea than any other species has about what to eat or who they are. Clearly, other species don’t “know” anything in the context that we know it.
But most people tend to ignore the fact that it is food that makes us who we are and pheromones that tell others who and what we are — just as the epigenetic effects of food odors and pheromones do in every other species on the planet. Thus, knowing what other animals don’t know may not differentiate us from them in terms of our animalistic behaviors.
To avoid being too animalistic, we must first think about what we know. Those who were taught all that they know by people who believed in mutations theory, may know so little about biological facts that they cannot claim to know anything useful in the context of understanding their behavior. They are less like people than like insects in that context.