Editor’s note: In his new book Evolution: Still a Theory in Crisis, Michael Denton not only updates the argument from his groundbreaking Evolution: A Theory in Crisis (1985) but also presents a powerful new critique of Darwinian evolution. This article is one in a series in which Dr. Denton summarizes some of the most important points of the new book. For the full story, get your copy of Evolution: Still a Theory in Crisis. For a limited time, you’ll enjoy a 30 percent discount at CreateSpace by using the discount code QBDHMYJH.
Beyond what I have said in the last two articles in this series, there is another line of evidence that supports the self-organizational, emergent paradigm, springing from the development of human language.
If the basis of language lay in genetically determined complex neural networks in the left side of the brain, then one might expect that damage to the areas in the left hemisphere known to be involved in language processing, i.e., Wernicke’s and Broca’s areas, would lead to linguistic impairment. While this is true in adults, and explains various aphasias, curiously, children can recover language ability even after these regions are lost. Amazingly, children who have lost their entire left hemisphere (which contains the key regions for language processing in normal adults) are still able to acquire and learn language.
In The Symbolic Species: The Co-Evolution of Language and the Brain, Terrence W. Deacon confesses: “The fact that hemispherectomized children can learn any aspect of language is a miracle.”1 And later in the same work he concludes: “We are not adapted just for symbolic learning but for fail-safe symbolic learning.“2 This is a phenomenal case of robust self-organization — the regeneration of the entire language organ via a novel route — and constitutes dramatic evidence that the generation of the language organ is primarily a matter of neural self-organization rather than of detailed genetic specification. The ability of children to reconstitute the language organ in a different part of the brain is an example of the profound general plasticity of the brain.
In his book The Brain that Changes Itself psychoanalyst Norman Doidge provides an inventory of clinical cases that indicate the brain’s wondrous plasticity and ability to recover from massive lesions by re-inventing neural abilities from scratch, amazingly often in different regions of the brain. The examples range from stroke patients learning to speak again to the remarkable case of a woman born with half a brain that rewired itself to work as a whole so efficiently that as Doidge comments: “A neurologist would not likely guess, without a brain scan, that a whole hemisphere is missing.”3
Given the evidence that the brain possesses amazing powers of self-regeneration and remodeling and that the generation of linguistic ability during ontogeny is the result of the self-organization of the developing brain, surely self-organizational phenomena must have also played a crucial if not decisive role in phylogeny.The origin of our intellectual and linguistic abilities must have involved internal causal factors in addition to natural selection.
A massive consilience of evidence tells against the notion that our novel intellectual abilities and linguistic competence arose from a prolonged evolutionary process, directed by cumulative selection, which gradually reconfigured a vast suite of genetic changes in the genome and a corresponding set of neuronal changes in the brain.
In short, there are simply no cogent reasons for inferring that language and our higher mental faculties were acquired over hundreds of thousands of generations by gradual cumulative selection of tiny genetic changes in small populations of hunter-gatherers on the plains of Pleistocene Africa. As far as this taxon-defining trait is concerned, everything points to the conclusion of Wallace and to the saltational model of Chomsky: to emergence, to epigenesis, to self-organization, and to internal causal factors as having played a decisive role.
(1) Deacon, The Symbolic Species: The Co-Evolution of Language and the Brain, 311.
(2) Ibid., 413, emphasis in original.
(3) Ibid., 258.
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