Excerpt: Romantic (erotic) love, an important component of human reproductive and sexual behavior, has its origins in parenting behavior. In reptiles, there is neither parental care nor an affectionate or affiliative bond between the two parents. Parental care evolved separately in birds and mammals and, as first pointed out by Eibl-Eibelsfeldt, “with parental care love came into the world ”
My comment: Claims that behavioral traits somehow concurrently evolved with morphological traits are consistently made without any biologically-based experimental evidence to support them. Serious scientists have refuted those claims with experimental evidence that shows how nutrient-dependent RNA-directed DNA methylation links amino acid substitutions and chromosomal rearrangements from ecological variation to ecological adaptations in species from microbes to man.
For example, Horton et al., (2014) linked differences in parental feeding to different morphological and behavioral traits in white-throated sparrows.The physiology of reproduction is controlled by the metabolism of nutrients to species-specific pheromones in birds, which links differences in their morphological and behavioral phenotypes to mammals via conserved molecular mechanisms detailed in Nutrient-dependent/pheromone-controlled adaptive evolution: a model.
From the same educational source: “Sex Archive Info,” see also: The Mind’s Eyes: Human pheromones, neuroscience, and male sexual preferences. Human ethologists, evolutionary theorists, and most social scientists seem to believe that heterosexual love evolved separately in birds and mammals, which suggests that mutations and/or parental love is the cause of homosexual preferences. I found that pseudoscientific nonsense even more difficult to believe than any of the other pseudoscientific nonsense that theorists have touted for decades.
Therefore, I first published an award-winning review (with human ethologist co-authors) that linked hormone-organized and hormone-activated behaviors in all vertebrates and invertebrates. See: Human pheromones: integrating neuroendocrinology and ethology.
My co-authors did not want to address any issues of sexual orientation in a follow-up with me, so I published the award-winning monograph The Mind’s Eyes: Human pheromones, neuroscience, and male sexual preferences as a journal article concurrently published as a book chapter in the Handbook of the Evolution of Human Sexuality.
Meanwhile, the claims of human ethologists and evolutionary theorists have continued to become more ridiculous as scientific progress is made by serious scientists more than 50 years after Dobzhansky (1964) described the difference between theorists and serious scientists. “…the only worthwhile biology is molecular biology. All else is “bird watching” or “butterfly collecting.” Bird watching and butterfly collecting are occupations manifestly unworthy of serious scientists!”
Some things do not change. Bird watchers (e.g., human ethologists) make the same claims about evolved behaviors that they have always made. Their claims continue to be based on observations instead of evidence that links conserved molecular mechanisms of biologically-based cause and effect in species from microbes to man via their nutrient-dependent pheromone-controlled behaviors.