Epigenesis and the evolution of the human brain.

This article proposes an hypothesis for the evolution of the human brain. It is based on the concepts of (i) regulation of nerve cell proliferation, and (ii) selective stabilisation of synapses during development. The former process is supposed to be rigidly regulated by the genome, while the latter (selective stabilisation) is proposed as developing in a more plastic manner. It is suggested here that genetic alterations of the regulation of neuroblast proliferation led to epigenetic rearrangements in selective synapse stabilisation, thus producing significant changes in cerebral connectivity. This view is in agreement with the punctuationalist theory of human evolution, and differs from other approaches to human nature, such as structuralist grammar and sociobiology.

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