Article excerpts: “A single pairing of the odorant with the MP was then sufficient to rapidly induce a differential activation of brain regions assumed to play a role in associative processes, such as the amygdala and the posterior piriform cortex, during subsequent re-exposure to the learned odorant.”
“…learning-induced neuronal rearrangements that link the perception of an initially neutral odorant with motor responses related to the vital need of sucking.”
Modified Fos expression indicates the direct epigenetic effect of the MP (i.e., the Mammary Pheromone) on intracellular signaling and stochastic gene expression that is required for adaptive evolution. It’s an innate (i.e., unlearned) response. The effect of the pheromone is the same as the effect of nutrient chemicals except for species specificity, which is required to link the genetically predisposed response to mammalian behaviors that are required for species survival in species from microbes to man (e.g., all of them that require nutrient chemicals for individual survival and the metabolism of the nutrient chemicals to pheromones that control reproduction).
Any attempt to make the response to pheromones one that must be learned is a misrepresentation of what is already known about cause and effect at the molecular level by those who are informed enough to know better. A recent interpretation of work with mice stated that smells must be learned before the behaviour can occur. If the genetically predisposed response to pheromones required learning in any species, it seems unlikely to me that there would be more than one species. Is there a model for that? Could a random mutation concurrently cause a change in the genome and another change in the genetic predisposition of an organism to respond to it sensory environment in the context of adaptive evolution– as is required where adaptive evolution is nutrient chemical-dependent and reproduction is pheromone controlled?
What if the first species had to learn how to respond to the pheromones of conspecifics before behaving appropriately in the context of that species — species-specific behaviors? Could we have evolved?