Physiological Gracility of Anatomically Modern Humans: Human Self-Domestication or Gene Tic)-Epigene (Tic)-Culture Co-Evolution?

The topic of genetic and epigenetic transformations determined by repeated contacts and prolonged periods of coexistence between different human types and species during the late Paleolithic, highlighted by the data obtained from the reconstruction of the genome-wide of ancient DNA and from the analysis of samples dating back to the Middle and to the Upper Paleolithic, is addressed in section 1. The so-called Human self-domestication hypothesis (HSD), which points to the possibility that the reduced emotional reactivity and increased self-control resulting from HSD have created a unique form of human tolerance that allows for the expression of more flexible social skills observed in anatomically modern humans, is discussed in section 2. In section 3 an alternative explanation of how and when the anatomically modern human lineage arose is presented. Since humans began to think and feel the world in terms of subject and object, distinguishing themselves from Nature (relation of contiguity) and ceasing to identify with it (relation of continuity), the human communities also developed the ability to create and produce culture. Culture production plays a (epigenetic) decisive role in order to i) favor complex processes of coevolution between individuals of the same or different (domesticated) species, which in many cases involves symbiosis or mutualism, in order to favor increased in-group prosociality over emotional reactivity, ii) trigger epigenetic mechanisms in the rapid phenotypic changes (that can be assimilated as genetic variants), also observed as outcome of domestication along with neuroanatomical, neurophysiological and neurocognitive changes specific to anatomically modern humans, iii) favor the activation of the capacity for complex iterative learning, necessary for cultural transmission, with or without oral language. Conclusions suggest that the recent evolution of anatomically modern humans, especially after the split with Neanderthals, can be understood as the outcome of gene(tic)-epigene(tic)-culture coevolution, rather than by self-domestication against emotional reactivity.