Reported in the context of: White Matter NAA/Cho and Cho/Cr Ratios at MR Spectroscopy Are Predictive of Motor Outcome in Preterm Infants
Excerpt 1): “The imaging studies were focused on the white matter of the brain, which is composed of nerve fibers that connect the functional centers of the brain.”
Excerpt 2): “…the presence of two chemical ratios — increased choline/creatine (Cho/Cr) and decreased N-acetylaspartate/choline (NAA/Cho) — at birth were significantly correlated with developmental delays one year later.”
Excerpt 3): “Our hope is to find a robust biomarker that we can use as an outcome measure so that we don’t have to wait five or six years to see if an intervention has worked.”
My comment: In my model of nutrient-dependent pheromone-controlled ecological adaptations sans mutations, the luteinizing hormone (LH) response to maternal pheromones is the biomarker that is most likely to directly link the prenatal metabolism of choline and other nutrients to their postnatal metabolism and brain development, which has canonically been indirectly associated with brain imaging of white matter (for example see Cantor and Blanchard, 2012).
For an accurate representation of biologically based cause and effect, see: Kohl (2013)
“The recently detailed mouse model (Li et al., 2013) builds on what is known about olfactory/pheromonal communication in species from microbes to man and incorporates works from mammals that elucidate the molecular mechanisms that are clearly involved. Sex-dependent production of a mouse ‘chemosignal’ with incentive salience appears to have arisen de novo via coincident adaptive evolution that involves an obvious two-step synergy between commensal bacteria and a sex-dependent liver enzyme that metabolizes the nutrient chemical choline.”
Is the LH response to maternal pheromones a biomarker for nutrient-dependent pheromone-controlled brain development? If so, it becomes clearer that claims about naturally selected sexual orientation associated with brain imaging are claims that support my model, which refutes the theory that sexual orientation is a matter of choice, or that sexual orientation is naturally selected.
The question arises: For comparison, what model of prenatal and postnatal brain organization do researchers use to link brain imaging of white matter to natural selection and sexual orientation? A common sense approach (e.g, the sense that is common to all species is olfaction) suggests that the LH response to pheromones links the sexual orientation of rams to sexual orientation in human males. That common sense approach explains why, in a recent documentary: “The Nature of Things-Survival of the Fabulous,” Anne Perkins left it to the evolutionary biologists to explain how sexual orientation might be naturally selected. Currently, no experimental evidence suggests that it is. Instead, experimental evidence supports my model.
Unfortunately, evolutionary biologists have typically avoided discussion of anything that might link mutation-initiated natural selection or its representation in mutation-driven evolution to sexual orientation. Their failure to address the biology of how variations of sexual orientation arise may contribute to opinions that sexual preferences are a matter of personal choice. Thus, portrayals of natural selection for sexual orientation based on brain imaging of white matter and responses to visual input may contribute to opinions that are uninformed by what is known about the conserved molecular mechanisms of mammalian brain development. The conserved molecular mechanisms have been detailed and exemplified with experimental results from studies of mice and sheep.
Perhaps researchers should use brain imaging of white matter to link the development of sexual preferences in mice and sheep to their responses to visual input. Arguably, that sounds like a ridiculous waste of time. Most people already accept the fact that all other mammals are primarily olfactory creatures and that other mammals do not choose how their brains develop. That fact suggests that other mammals do not naturally select or choose their sexual preferences. However, grant money may be available for researchers who have a vested interest in maintaining their status as experts on sexual orientation based on their results from human brain imaging of white matter and responses to visual input. Potentially, they could continue to claim that “further research is required” since that is always the case — especially for those touting theories about human brain development that don’t seem to fit into the context of what is known about biological facts.