From issue 2882 of New Scientist magazine, page 30-35.
“Each of your cells contains the entire history of human evolution, beginning at the dawn of life 3 billion years ago. This week’s cover story tells that surprisingly twisty tale.”
A brief history of the human genome
- 17 September 2012 by Michael Le Page
Excerpt: “We are the descendants of a long line of lottery winners, a lottery in which the prize was producing offspring that survived long enough to reproduce themselves.”
My comment: Do people still think like that? Data from the ENCODE project attest to the odds against any individual of any species surviving long enough to reproduce. The only way to beat those odds would be to allow nutrient chemicals to epigenetically effect intracellular signaling and stochastic gene expression so that de novo “odor” receptors could allow additional nutrient chemicals to enter the cell as occurs in the presence of what was, until recently, called junk DNA. (Of course, “junk” DNA actually is what codes for nutrient chemical-dependent gene duplication of odor receptors, but that’s another story.)
Until it’s told, here’s the rest of the current story. The metabolism of the nutrient chemicals to individual mixtures of species-specific pheromones allows for self / non-self recognition as is required at the advent of sexual reproduction (e.g., in yeasts). That means the pheromones controlling reproduction via quorum sensing activity in unicellular organisms went on to control nutrient chemical-dependent sexual reproduction in species from microbes to man via the same molecular mechanisms (e.g., the ones that have obviously been conserved.)
Remember: nutrient chemicals epigenetically effect intracellular signaling and stochastic gene expression. The pheromones that control reproduction do that, too, which is how they control speciation. Against the explanatory power of this model which incorporates extension of a concept: i.e., the epigenetic tweaking of immense gene networks in superorganisms that solve problems through the exchange and the selective cancellation and modification of signals, we have the all-together powerless random mutations theory of accidents and mistakes that enabled adaptive evolution, which can only occur via nutrient chemical-dependent and pheromone-dependent ecological, social, neurogenic, and socio-cognitive niche construction.
Thus, it is now clearer how an environmental drive probably evolved from that of food ingestion in unicellular organisms to that of socialization in insects. It is also clear that, in mammals, food odors and pheromones cause changes in hormones that have developmental affects on sexual behavior in nutrient-dependent, reproductively fit individuals across species of vertebrates.
Arguably, some mistakes might have been made along the way to construction of our socio-cognitive niche, which allows us to decide whether or not we believe they are mistakes, and also to determine how many more mistakes we may decide to make during the course of our individual attempts to win the nutrient chemical-dependent and pheromone-dependent “lottery” that results in survival of our genes.
It might be a mistake to have another burger and more fries, gain that nutrient chemical-dependent weight that makes you obese; makes you smell funny; leads to systemic inflammation and cancer, and let it kill you. Similarly, attempts to indiscriminately reproduce at each opportunity might lead to additional viral load acquired from conspecifics who sicken you and who find your lack of physical fitness to be sickening. Once your individual decision is made in that context, write to “New Scientist” and tell us all: “How’s that working for ya?” Did you and your kin-folk beat the odds and win the “lottery”? Did anyone else?