- Editors’ Choice
Benjamin M. Neale
Genetic variation that is deleterious is on average younger than neutral variation.
Article excerpt: “…the age of a variant may help to identify that subset of genetic variation that has an impact on human disease.”
My comment: This age-variant approach is consistent with reports on the recent origin of most human protein-coding variants. For example, “Even though new genetic variants arise through mutation in each generation, most are present only in a small proportion of individuals because they have slightly negative effects on fitness.” This explains why mutations are not known to contribute to adaptive evolution.
For contrast, it is now clearer that the thermodynamics of epigenetically effected chromatin remodeling is manifested in organism-level thermoregulation and nutrient-dependent pheromone-controlled reproduction, which obviously contributes to adaptive evolution that occurs via ecological, social, neurogenic, and socio-cognitive niche construction. This fact brings evolutionary theory forward in the context of Darwin’s “Conditions of Existence,” which are established before natural or sexual selection can occur. We now know that Darwin’s conditions of existence are nutrient-dependent and pheromone-controlled in species from microbes to man.