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Neural Darwinism, a large scale theory of brain function by Gerald Edelman, was initially published in 1978, in a book called ''The Mindful Brain'' (MIT Press). It was extended and published in the 1987 book ''Neural Darwinism – The Theory of Neuronal Group Selection''. In 1972, Edelman was awarded the Nobel Prize in Medicine or Physiology (shared with Rodney Porter of Great Britain) for his work in immunology showing how the population of lymphocytes capable of binding to a foreign antigen is increased by differential clonal multiplication following antigen discovery. Essentially, this proved that the human body is capable of creating complex adaptive systems as a result of local events with feedback. Edelman's interest in selective systems expanded into the fields of neurobiology and neurophysiology, and in ''Neural Darwinism'', Edelman puts forth a theory called "neuronal group selection". It contains three major parts: # Anatomical connectivity in the brain occurs via selective mechanochemical events that take place epigenetically during development. This creates a diverse primary repertoire by differential reproduction. # Once structural diversity is established anatomically, a second selective process occurs during postnatal behavioral experience through epigenetic modifications in the strength of synaptic connections between neuronal groups. This creates a diverse secondary repertoire by differential amplification. # Reentrant signaling between neuronal groups allows for spatiotemporal continuity in response to real-world interactions. In "The Remembered Present" (1989) and later, "Bright Air, Brilliant Fire: On the Matter of the Mind" (1992) and "A Universe of Consciousness: How Matter Becomes Imagination" (2001; coauthored with Giulio Tononi), Edelman argues that thalamocortical and corticocortical reentrant signaling are critical to generating and maintaining conscious states in mammals. ==Degeneracy== With neuronal heterogeneity (by Edelman called ''degeneracy''), it is possible to test the many circuits (on the order of 30 billion neurons with an estimated one quadrillion connections between them in the human brain) with a diverse set of inputs, to see which neuronal groups respond "appropriately" statistically. Functional "distributed" (widespread) brain circuits thus emerge as a result. Edelman goes into some detail about how brain development depends on a variety of cell adhesion molecules (CAMs) and substrate adhesion molecules (SAMs) on cell surfaces which allow cells to dynamically control their intercellular binding properties. This surface modulation allows cell collectives to effectively "signal" as the group aggregates, which helps govern morphogenesis. So morphology depends on CAM and SAM function. And CAM and SAM function also depend on developing morphology. Edelman theorized that cell proliferation, cell migration, cell death, neuron arbor distribution, and neurite branching are also governed by similar selective processes. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Neural Darwinism」の詳細全文を読む スポンサード リンク
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