Re: [evol-psych] Paper: Major histocompatibility complex peptide ligands as olfactory cues in human body odour assessment
- James V. Kohl
Can You Smell Yourself? by Sarah C. P. Williams on 22 January 2013, 5:10 PM
Excerpt: "Other molecules the human body produces could also influence individual smells and scent preferences, Zufall says. The individuality of people's microbiomes—the collection of microbes living in and on us—could also be linked to the body's odor or preferences, Wedekind says. "We just don't know the full physiology yet," he said, "But this is a good start."
My comment: The full physiology has been detailed. The details are based on common molecular mechanisms and the epigenetic effects of nutrients and pheromones on individual survival and species diversification. Self vs non-self recognition is a function of the metabolism of nutrients to pheromones in species from microbes to man.
Excerpt 1: "... activation of particular brain regions by exposure... [reflects] ‘self’ or ‘non-self’ qualities relative to the individual's MHC genotype."
Excerpt 2: "...our study suggests that, as in mice and fish, sensory evaluation of MHC diversity through the recognition of structurally diverse MHC ligands may be involved in human MHC-associated behaviour."
My reflection on their suggestion: Gonadotropin releasing hormone (GnRH) emerged as a early regulator of reproduction. For example, the yeast α mating factor has 80% amino acid homology with mammalian GnRH. It also stimulates gonadotropin release from the mammalian pituitary. The discovery of the fact that one decapeptide molecule, among the GnRHs, was constructed perfectly at the beginning of 400 million years [of vertebrate] evolution and that it is not possible to improve its physiological potency using the any natural amino acid is, in my opinion, important...." It may also be important to note that mice and sticklebacks are vertebrates.
We can then look at an earlier work co-authored by the senior author of this latest report. Here -- with a 2004 Nobel Laureate as another co-author -- we find evidence that Feedback loops link odor and pheromone signaling with reproduction. The link is GnRH. "Indications that GnRH peptide plays an important role in the control of sexual behaviors suggest that pheromone effects on these behaviors might also involve GnRH neurons."
The statement above translates to: The epigenetic effects of vertebrate pheromones on GnRH links nutrient-dependent pheromone production and feedback loops to food odors and to pheromones, which control of reproduction in species from microbes to man.
Are pheromones anything less than the most powerful influence on the adaptive evolution of human behavior?
In Milinski et al (2013), human pheromones are body odors. The body odors of all other animals are pheromones. Does the refusal to acknowledge the role of human pheromones in adaptively evolved human behavior exemplify academic nonsense, or ignorance of the full physiology that links nutrient-dependent pheromone-controlled reproduction to behavior in species from microbes to man?
Medical laboratory scientist (ASCP)
Kohl, J.V. (2012) Human pheromones and food odors: epigenetic influences on the socioaffective nature of evolved behaviors. Socioaffective Neuroscience & Psychology, 2: 17338.
From: Robert Karl Stonjek <stonjek@...>
To: Evolutionary-Psychology <email@example.com>
Sent: Thu, January 31, 2013 6:53:15 AM
Subject: [evol-psych] Paper: Major histocompatibility complex peptide ligands as olfactory cues in human body odour assessment
Major histocompatibility complex peptide ligands as olfactory cues in human body odour assessmentManfred Milinski1, Ilona Croy2,3, Thomas Hummel2 and Thomas Boehm41Department of Evolutionary Ecology, Max Planck Institute of Evolutionary Biology, August-Thienemann-Strasse 2, 24306 Ploen, Germany2Department of Otorhinolaryngology, University of Dresden Medical School, Fetscherstrasse 74, 01307 Dresden, Germany3Department of Occupational and Environmental Medicine, University of Gothenburg, Medicinaragatan 16, 40530 Gothenburg, Sweden4Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, Stuebeweg 51, 79108 Freiburg, Germanye-mail: boehm@...
In many animal species, social communication and mate choice are influenced by cues encoded by the major histocompatibility complex (MHC). The mechanism by which the MHC influences sexual selection is a matter of intense debate. In mice, peptide ligands of MHC molecules activate subsets of vomeronasal and olfactory sensory neurons and influence social memory formation; in sticklebacks, such peptides predictably modify the outcome of mate choice. Here, we examine whether this evolutionarily conserved mechanism of interindividual communication extends to humans. In psychometric tests, volunteers recognized the supplementation of their body odour by MHC peptides and preferred ‘self’ to ‘non-self’ ligands when asked to decide whether the modified odour smelled ‘like themselves’ or ‘like their favourite perfume’. Functional magnetic resonance imaging indicated that ‘self’-peptides specifically activated a region in the right middle frontal cortex. Our results suggest that despite the absence of a vomeronasal organ, humans have the ability to detect and evaluate MHC peptides in body odour. This may provide a basis for the sensory evaluation of potential partners during human mate choice.
Source: The Royal Society [Open Access Paper]
Robert Karl Stonjek