Pathways to elaboration of sexual dimorphism in bird plumage patterns
Reported on 12/19/13 as Evolution of Plumage Patterns in Male and Female Birds
Excerpt: “…what I found was that plumage patterning is remarkably labile — both male and female birds have the capacity to change between different types of patterns. What’s interesting is to consider what are the forces driving these changes in male and female plumage patterns…”
My comment: In my model, ecological variation results in amino acid substitutions and adaptations. For example, we know that in some birds “…a single amino acid substitution contributes to speciation.” No experimental evidence suggests a link from any mutation to different plumage color is involved in speciation. “Birds from a second satellite island (Ugi) do not show the same perfect association between this MC1R variant and plumage color, suggesting an alternative mechanism for melanism on this island.”
We now have learned more about ecological variation and the remarkably labile plumage patterns of other birds. “We propose that other genes such as POMC, Agouti or any other genes involved in pigment synthesis will need to be investigated in future studies if we are to understand how selection shapes complex patterns of melanin-based plumage pigmentation.” What we’ve learned about DNA methylation from Agouti alone will make it harder for theorists to claim that mutation-initiated natural selection is responsible for species diversification associated with plumage color.
What we’ve learned about plumage patterns will also make it harder for theorists to emphasize the importance of auditory cues or anything other that what is known to cause nutrient-dependent pheromone-controlled ecological adaptations in every other species on the planet.
Clearly, we’ve learned that experimental evidence must begin to support the theorists claims. For example, in all vertebrates, the de novo creation of olfactory receptor genes is linked to amino acid substitutions and species diversity. See for more information: Birds: A single amino acid change and plumage (11/24/13)