Birds: A single amino acid change and plumage

Differential effects of global versus local testosterone on singing behavior and its underlying neural substrate Beau A. Alward, Jacques Balthazart, and Gregory F. Ball (published ahead of print November 11, 2013)

1. Excerpt: “These results have broad implications for research concerning how steroids act at multiple brain loci to regulate distinct sociosexual behaviors and the associated neuroplasticity.”

2. By subsequently experimentally elevating testosterone (T) in half of the males during the non-breeding season we showed that the OB [Olfactory bulb] volume was increased compared to controls.

3. Here we experimentally demonstrate opposing effects of frequency-dependent social environments on plasma hormone levels (testosterone and corticosterone) and immune function between red- and black-headed male morphs of the Gouldian finch (Erythrura gouldiae).

4. The increases in LH [luteinizing horomone] plasma concentrations are in all probability triggered by increases in GnRH secretion, and, as a consequence, it has long been assumed that the preoptic GnRH neurons represent the target where information about photoperiod and additional cues must converge to regulate reproduction.

5. See also Bird odour predicts reproductive success.

Clearly, science works best when alternative hypothesis can be experimentally tested. If experimental evidence supports a null hypothesis that is unknown to me, the birds are primarily visual or auditory creatures. If not, given what is known about amino acid change and plumage, they are primarily olfactory creatures like all other creatures on this planet.

I would like to examine any evidence that supports a bird-brained type of associated null hypothesis to determine its validity in the context of  the facts represented in items 1-5 above, which obviously effect hormones, the brain, and behavior in birds. When that evidence becomes available to me, it can be compared in the context of what is currently known about plumage color: Difference in Plumage Color Used in Species Recognition between Incipient Species Is Linked to a Single Amino Acid Substitution in the Melanocortin-1 Receptor, reported as “Birds use plumage colour to recognize and select potential mates.”

The single amino acid substitution of plumage color links the biophysical constraints of  thermodynamics and organism-level thermoregulation to protein folding in the human influenza A/H3N2 virus, and to its  receptor-mediated antigenic effects. See for example: Substitutions Near the Receptor Binding Site Determine Major Antigenic Change During Influenza Virus Evolution.

As I noted in my blog post on Antigenic change due to a single amino acid and in my comment on the Science Magazine article linked above: “The idea of biophysical constraints seems antithetical to the idea of nature somehow selecting mutations that cause amino acid substitutions. ”


About James V. Kohl 1308 Articles
James Vaughn Kohl was the first to accurately conceptualize human pheromones, and began presenting his findings to the scientific community in 1992. He continues to present to, and publish for, diverse scientific and lay audiences, while constantly monitoring the scientific presses for new information that is relevant to the development of his initial and ongoing conceptualization of human pheromones. Recently, Kohl integrated scientific evidence that pinpoints the evolved neurophysiological mechanism that links olfactory/pheromonal input to genes in hormone-secreting cells of tissue in a specific area of the brain that is primarily involved in the sensory integration of olfactory and visual input, and in the development of human sexual preferences. His award-winning 2007 article/book chapter on multisensory integration: The Mind’s Eyes: Human pheromones, neuroscience, and male sexual preferences followed an award winning 2001 publication: Human pheromones: integrating neuroendocrinology and ethology, which was coauthored by disinguished researchers from Vienna. Rarely do researchers win awards in multiple disciplines, but Kohl’s 2001 award was for neuroscience, and his 2007 “Reiss Theory” award was for social science. Kohl has worked as a medical laboratory scientist since 1974, and he has devoted more than twenty-five years to researching the relationship between the sense of smell and the development of human sexual preferences. Unlike many researchers who work with non-human subjects, medical laboratory scientists use the latest technology from many scientific disciplines to perform a variety of specialized diagnostic medical testing on people. James V. Kohl is certified with: * American Society for Clinical Pathology * American Medical Technologists James V. Kohl is a member of: * Society for Neuroscience * Society for Behavioral Neuroendocrinology * Association for Chemoreception Sciences * Society for the Scientific Study of Sexuality * International Society for Human Ethology * American Society for Clinical Laboratory Science * Mensa, the international high IQ society