
Get a Whiff of This
An issue of The Scientist (TS) devoted to the latest research on how smells lead to actions
October 1, 2013
|Excerpt: Once a year, TS devotes the better part of an issue to one of the senses. In 2011 it was taste; 2012, touch; this year, smell.
My comment: TS mentioned the 1995 publication of The Scent of Eros: Mysteries of Odor in Human Sexuality here: see Scent of a Book Deal.
Human pheromone-deniers can now be approached in the context of what’s been scientifically supported by experiments in different model organisms since 1995.
For example, although moths perceive diverse floral species similarly, nutrient-dependent reproduction is pheromone-controlled in species from microbes to man via the conserved molecular mechanisms of ecological, social, neurogenic and socio-cognitive niche construction. Olfactory / pheromonal input epigenetically effects the experience-dependent alternative splicings that link the de novo creation of olfactory receptor genes in moths to the hormone-organized and hormone-activated behavior of invertebrates and vertebrates, like us, as we detailed in our 1996 Hormones and Behavior review article.
There are now examples of nutrient-dependent pheromone-controlled epigenetic cause and effect in many different model organisms, including yeasts, nematodes, insects, other mammals, and a human population that adaptively evolved in what is now central China during the past ~30,000 years. I included these examples in a more recent review of nutrient-dependent amino acid substitutions, although some of the model organisms were also mentioned in our section on molecular epigenetics in our 1996 review.
The most telling example in the now-refuted context of mutation-driven evolution remains a species of moth in which a single nutrient-dependent substitution of a critical amino acid creates a new pheromone blend. Although the substitution might be considered by some to be the result of a mutation, we now know there is no evidence that mutations are fixed in the organized genome of any species. (Sickle-cell anemia, for example, is not the result of a gene that is fixed in all human populations.)
What is obvious, for comparison, is that new alleles are fixed via nutrient uptake (e.g., glucose and amino acids) and the thermodynamics of pheromone-controlled reproduction associated with organism-level thermoregulation. Thus, fiixation can be directly attibuted to the epigenetic effects of olfactory/pheromonal input that are associated with other sensory input during the development of food preferences and mate preferences in species from microbes to man. Therefore, we have reached the point the where nutrient-dependent pheromone-controlled physiology of reproduction must be the first consideration when any attempt is made to link sensory input to the Physiology [that] is rocking the foundations of evolutionary biology.
Clearly, the conserved molecular mechanisms of nutrient-acquisition and pheromone-controlled reproduction are the foundations of evolutionary biology and the Mysteries of Odor in Human Sexuality. This was predicted more that 30 years ago.
“I should think we might fairly guage the future of biological science, centuries ahead by estimating the time it will take to reach a complete comprehensive understanding of odor. It may not seem a profound enough problem to dominate all the life sciences, but it contains, piece by piece, all the mysteries.” — Lewis Thomas (1980) as cited in The Scent of Eros: Mysteries of Odor in Human Sexuality