Mysterious episodes of genetic duplication in our great ape ancestors may have paved the way for human evolution
By Emily Singer and Quanta Magazine
Excerpt: While evidence that core duplicons are a driving force behind human evolution is growing, many questions remain. For example, it’s unclear what triggered the creation of these cores or how they spread.
My comment: Two things may be the driving force behind human evolution.
1) mutation initiated natural selection placed into the context of mutation-driven evolution
2) ecological variations placed into the context of adaptations and species diversification via the increased complexity of ecological, social, neurogenic, and socio-cognitive niche construction.
All experimental evidence supports the role of ecological variations in adaptations. No experimental supports the role of mutations in the creation of core duplicons or their spread. Instead, the most recent report on de novo creation of genes in microbes clearly shows that the amino acid substitutions that differentiate cell types are nutrient-dependent. Since the physiology of reproduction in microbes is pheromone controlled, it is easier to explain the creation and spread of core duplicons in the context of nutrient-dependent pheromone-controlled amino acid substitutions. Attributing the amino acid substitutions to mutations that differentiate cell types leaves researchers with a theory about uncontrolled mutation-driven evolution that can be compared to a model of ecological variation and adaptations in species from microbes to man that is nutrient-dependent and pheromone-controlled.
The core duplicon appears to be an unstable genetic element, which provides a template for the stabilization of evolutionary changes.
Excerpt 2: ““It’s possible that we are the way we are largely because of this mechanism that generates dramatic episodes of chromosomal structural change.” PZ Myers recently mentioned what may be a similar hypothesis. Myers wrote: Evolution was all due to chromosome rearrangements, which somehow are not mutations, and he also somehow ignored the existence of allelic differences between species. The link is to the late John A. Davison’s blog post in the context of PZ Myers accusation that Davison was, like me, a “crank.”
Excerpt 3: “While evidence that core duplicons are a driving force behind human evolution is growing, many questions remain. For example, it’s unclear what triggered the creation of these cores or how they spread.”
What seems to be missing here is anything that might otherwise link mutation-initiated natural selection to gene duplications, which suggests to me that the duplications are nutrient-dependent. If so, ecological variation and nutrient-dependent pheromone-controlled duplicons are more likely to be the driving force behind human adapations, which leaves mutations to be the driving force behind unstable cell types and diseases or disorders. Of course, that fact turns people like PZ Myers in “cranks” who are so cranky as to insist that anyone who disagrees with them is a crank.