Clearly there are no foolish questions, even though I felt like a fool after I asked a general question about changes in the microRNA/messenger RNA balance (at a SFN 2012 presentation). The speaker politely confirmed that the balance is probably responsible for all downstream epigenetic effects, which include epigenetic effects of nutrient acquisition and the epigenetic effects of their metabolism to pheromones, which control reproduction. Similarly, it might not be a foolish question to ask how females choose the ‘right’ sperm, as the conserved molecular mechanisms of nutrient-dependent pheromone-controlled adaptive evolution could then be revealed.
How females choose the ‘right’ sperm Posted: 16 Aug 2013 06:48 AM PDT
Scientists have revealed how females select the ‘right’ sperm to fertilize their eggs when faced with the risk of being fertilized by wrong sperm from a different species. Researchers investigated salmon and trout. They found that when eggs from each species are presented with either salmon or trout, they allow fertilization by either species’ sperm. But if eggs are given a choice of both species’ sperm, they favor their own species’.
Article Excerpt: “So what we’re seeing is that ovarian fluid gives a specific chemical signal to the sperm of its own species, causing changes in the way their tails beat, so that they swim in a straighter trajectory, and therefore guided more effectively towards the site of fertilization.”
Human Male Superiority in Olfactory Sensitivity to the Sperm Attractant Odorant Bourgeonal (2010) Available for FREE
Abstract excerpts (with my emphasis):
“…sperm chemotaxis critically involves the human olfactory receptor OR1D2, which is activated by the aromatic aldehyde bourgeonal. Given that both natural and sexual selection may act upon the expression of receptors…”
“Single nucleotide polymorphisms and/or copy number variations in genes coding for olfactory receptors may be the proximate cause for our finding, whereas a gender difference in the behavioral relevance of bourgeonal may be the ultimate cause.”
Although some evolutionary theorists might not recognize that the results from the human study parallel those from the report on the fish, it is important to learn that common molecular mechanisms involved in self vs non-self recognition are conserved across unicellular and multicellular species. Those common molecular mechanisms allow cells to incorporate olfactory/pheromonal input from the epigenetic landscape (via receptors in the cell wall) into the physical landscape of DNA in species from microbes to man.
After learning how to recognize the obvious similarities in receptor-mediated functions across species, it is easier to place them into the context of single nucleotide polymorphisms, amino acid substitutions, and/or copy number variations in genes coding for olfactory receptors. That is how nutrient-dependent pheromone-controlled proximate cause can be established. Simply put, “Olfaction and odor receptors provide a clear evolutionary trail that can be followed from unicellular organisms to insects to humans…” You should probably try to understand that fact before you begin to approach the adaptive evolution of the brain and behavior, lest you miss the only valid perspective and continue to tout mutation-driven evolution.
Also, as I recall, bourgeonol is not a naturally occurring species-specific pheromone in any species. Thus, the fact that it has even the slightest effect on human male perception (associated with its use in perfumes), which might be associated with sex differences in olfactory sensitivity, suggests a link both to the development of food preferences associated with only olfactory input (food odors and cosmetics). The odor of cosmetics might thus be enhanced by the addition of species-specific sexually dimorphic pheromones, as we showed in 2007 and in a 2008 replication of cause and effect (presumably on hormones that affect behavior), which resulted in this 2012 presentation of our results.
What we will see in October is more evidence that our 2012 representation of human pheromones is paralleled in results from studies of birds (e.g., see Songbird chemosignals: volatile compounds in preen gland secretions vary among individuals, sexes, and populations (2010) Available for FREE, in which female select mates for their masculine odor. These forthcoming results will be particularly distressing to anyone who has ever asked the question “What about birds?” after learning about the common molecular mechanisms of invertebrates and all other vertebrates. People like that can no longer posit theories based on the misrepresentation of olfactory/pheromonal input that make it appear to be less important to the development of human behavior than it is to the development of behavior in every other species on the planet. Simply put, it makes them appear to be so foolish as to make them regret asking the question. However, there are no foolish questions. What’s foolish is to pretend your questions have not been answered, and to continue touting mutation-driven evolution for more than 17 years (as Jay R. Feierman, moderator of The International Society for Human Ethology (ISHE) yahoo group did).