Is evolution as simple as the flip of a switch?
- BY EMILY SINGER, QUANTA MAGAZINE
- 1:20 PM
Excerpt: “In 1996, Susan Rosenberg, then a young professor at the University of Alberta, undertook a risky and laborious experiment. Her team painstakingly screened hundreds of thousands of bacterial colonies grown under different conditions, filling the halls outside her lab with tens of thousands of plates of bacteria. “It stank,” Rosenberg recalled with a laugh.
My comment: What “stank” was the concentration of species-specific pheromones that control the nutrient-dependent physiology of reproduction in species from microbes to man via conserved molecular mechanisms.
I this article, the biophysical constraints on ecological adaptations are removed from any consideration whatsoever. Stress-induced beneficial changes are simply attributed to mutations that cause diseases and disorders.
The same molecular mechanisms that perturb protein folding somehow also cause mutation-driven evolution to somehow occur via selection for something that theoretically occurs at the flip of a switch.
(SARCASM) Thus, ecological variation is not considered; mutation-driven evolution is accepted without question; and all is right in the world of theoretical biology that is based on mathematical models. Never mind the biological fact that all experimental evidence shows us ecological adaptations are nutrient-dependent and pheromone-controlled (e.g., the thousands of plates stank) via conserved molecular mechanisms in species from microbes to man. The important thing to know, according to this article, is that evolution “evolves.”
I reiterate: “In 1996, Susan Rosenberg, then a young professor at the University of Alberta, undertook a risky and laborious experiment. Her team painstakingly screened hundreds of thousands of bacterial colonies grown under different conditions…”
In 1996, our Hormones and Behavior review article: From Fertilization to Adult Sexual Behavior, included a section on molecular epigenetics that placed ecological adaptations into the context of nutrient-dependent (e.g., growth under different conditions) pheromone-controlled alternative splicings of pre-mRNA, which led to — among other differences — the sex differences in unicellular yeasts at the advent of nutrient-dependent pheromone-controlled physiology of sexual reproduction.
It will be interesting to someday read what others have since learned about how mutations led to sexual reproduction by “flipping” a “switch.” Meanwhile, according to this article, we know only that evolution evolves sex differences like it evolved all the other differences in cell types of individuals of all species.
(SARCASM) Evolution “flipped some switches,” like the one that caused eye regression in the cave fish.