Red, theory; black, fact.
In the previous post, "Goddesses of the Glacier," evolution appears to be operating in cooperation with a general capacity for technology. Natural selection operates on the brain pathways underlying our aesthetic preferences concerning our own appearance and that of possible reproduction partners and then a technology is automatically developed to satisfy them.
As a first example, consider the oil and brush technology previously assumed for differentiating women from men by hair smoothness. A further step in this direction is to posit that hair color may have been used to code gender. The first step would have been selection for a blond(e) hair colour in both women and men. Since this is a very light colour, it will show the effect of dyeing maximally. Concurrently with this, the aesthetic preferences of men and women would have been differentiated by selection, resulting in blonde women who experience a mild euphoria from being blonde and blond men who experience a mild dysphoria from the same cause. The men would predictably get busy inventing hair-dyeing technologies to rectify this. The necessary dyes are readily obtained from plant sources such as woad and walnut shells. The result would be an effective blonde-female/nonblond-male gender code.
This style of evolution could be very fast if the brain pathways of aesthetic preferences require few mutations for their modification compared with the number required for the equivalent direct modification of the body. Let us assume this and see where it leads.
Faster evolution is generally favored if humans are typically in competition with other species to be the first to occupy a newly possible ecological niche. Such niches will be created in abundance with every dramatic change in the environment, such as a glaciation and the following deglaciation. Possibly, these specific events just slide the same suite of niches to higher or lower latitudes, but the amount of land area in each is likely to change, leading to under-capacity in some, and thus opportunity. These opportunities will vanish much faster than evolution can follow unless a diversity of phenotypes is already present in the prospective colonizing population, which might happen as a result of genetic drift in multiple, isolated sub-populations.
If technologically assisted evolution has general advantages, then we can expect its importance to grow with increases in the reach of technology. Today, we seem to be at a threshold, with male-to-female and female-to-male gender transitions becoming well known. Demand for this service is probably being driven by disordered neural development during fetal life due to contamination of the fetus by environmental pollutants that have estrogenic properties (e.g., bisphenol A, PCBs, phthalates, etc.). The result is the birth of individuals with disordered and mutually contradictory, gendered aesthetic preferences, which is tragic. However, it is an interesting natural experiment.
With further development of cell biology in the direction of supporting body-modification technology, who knows what bizarre hankerings will see the light of day on demand from some customer? Remember that in evolution, the mutation comes first, and the mutation is random. Predictably, and sadly, most such reckless acts of self-indulgence will be punished by reduced employability and reduced reproductive success, doubtless exacerbated by prejudice on the part of the normal, normative majority.
However, the very occasional success story is also to be expected, involving the creation of fortuitously hyperfunctional individuals, and thus the technologically assisted creation of a new pre-species of human.
If the engineering details learned by the body-modification trade during this process are then translated into germ-line genetic engineering, then a true artificial humanoid species will have been created.
After the Pleistocene, the Plasticine.
Photo by Дмитрий Хрусталев-Григорьев on Unsplash