| | More evidence that humans have a different kind of cognition than animals do -- rather than just a different degree of the same kind of cognition:
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Hist Philos Life Sci. 2003;25(2):211-41.
The dual biological identity of human beings and the naturalization of morality.
Azzone GF.
Department of Experimental Biomedical Sciences, University of Padua, Padua, Italy.
The last two centuries have been the centuries of the discovery of the cell evolution: in the XIX century of the germinal cells and in the XX century of two groups of somatic cells, namely those of the brain-mind and of the immune systems. Since most cells do not behave in this way, the evolutionary character of the brain-mind and of the immune systems renders human beings formed by t wo different groups of somatic cells, one with a deterministic and another with an indeterministic (say Darwinian) behavior. An inherent consequence is that of the generation, during ontogenesis, of a dual biological identity.
The concept of the dual biological identity may be used to explain the Kantian concept of the two metaphysical worlds, namely of the causal necessity and of the free will (Azzone, 2001). Two concepts, namely those of complex adaptive systems (CAS) and of emergence (Holland, 2002), are useful tools for understanding the mechanisms of adaptation and of evolution.
The concept of complex adaptive systems indicates that living organisms contain series of stratified components, denoted as building blocks, forming stratified layers of increasing complexity. The concept of emergence implies the use of repeating patterns and of building blocks for the generation of structures of increasing levels of complexity, structures capable of exchanging communications both in the top-down and in the bottom-up direction.
Against the concept of emergence it has been argued that nothing can produce something which is really new and endowed of causal efficacy. The defence of the concept of emergence is based on two arguments. The first is the interpretation of the variation-selection mechanism as a process of generation of information and of optimization of free energy dissipation in accord with the second principle of thermodynamics. The second is the objective evidence of the cosmological evolution from the Big Bang to the human mind and its products.
Darwin has defended the concept of the continuity of evolution. However evolution should be considered as continuous when there is no increase of information and as discontinuous when there is generation of new information. Examples of such generation of information are the acquisition of the innate structures for language and the transition from absence to presence of morality. There are several discontinuity thresholds during both phylogenesis and ontogenesis.
Morality is a relational property dependent on the interactions of human beings with the environment. Piaget and Kohlberg have shown that the generation of morality during childhood occurs through several stages and is accompanied by reorganization of the child mental organization. The children respect the conventions in the first stage and gradually generate their autonomous morality.
The transition from absence to presence of morality, a major adaptive process, then, not only has occurred during phylogenesis but it occurs again in every human being during ontogenesis.
The religious faith does not provide a logical justification of the moral rules (Ayala, 1987) but rather a psychological and anthropological justification of two fundamental needs of human beings: that of rendering Nature an understandable entity, and that of increasing the cooperation among members of the human societies.
The positive effects of the altruistic genes in the animal societies are in accord with the positive effects of morality for the survival and development of the human societies.
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Recap:
The evolution of humans from lower animals is discontinuous because of the generation of new information like language and morality -- rather than the mere re-structuring of old information, as is true of the evolution of all other animals. Humans aren't "just" smarter animals.
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Med Sci (Paris). 2006 Jun-Jul;22(6-7):659-63.
[Survival of the fattest: the key to human brain evolution]
[Article in French]
Cunnane SC.
Centre de recherche sur le vieillissement, Département de médecine, physiologie et biophysiques, Faculté de médecine et sciences de la santé, Université de Sherbrooke, 1036, Belvédère Sud, Sherbrooke, Québec, J1H 4C4, Canada. stephen.cunnane@usherbrooke.ca
The circumstances of human brain evolution are of central importance to accounting for human origins, yet are still poorly understood. Human evolution is usually portrayed as having occurred in a hot, dry climate in East Africa where the earliest human ancestors became bipedal and evolved tool-making skills and language while struggling to survive in a wooded or savannah environment.
At least three points need to be recognised when constructing concepts of human brain evolution :
(1) The human brain cannot develop normally without a reliable supply of several nutrients, notably docosahexaenoic acid, iodine and iron. (2) At term, the human fetus has about 13 % of body weight as fat, a key form of energy insurance supporting brain development that is not found in other primates. (3) The genome of humans and chimpanzees is <1 % different, so if they both evolved in essentially the same habitat, how did the human brain become so much larger, and how was its present-day nutritional vulnerability circumvented during 5-6 million years of hominid evolution?
The abundant presence of fish bones and shellfish remains in many African hominid fossil sites dating to 2 million years ago implies human ancestors commonly inhabited the shores, but this point is usually overlooked in conceptualizing how the human brain evolved. Shellfish, fish and shore-based animals and plants are the richest dietary sources of the key nutrients needed by the brain. Whether on the shores of lakes, marshes, rivers or the sea, the consumption of most shore-based foods requires no specialized skills or tools.
The presence of key brain nutrients and a rich energy supply in shore-based foods would have provided the essential metabolic and nutritional support needed to gradually expand the hominid brain. Abundant availability of these foods also provided the time needed to develop and refine proto-human attributes that subsequently formed the basis of language, culture, tool making and hunting.
The presence of body fat in human babies appears to be the product of a long period of sedentary, shore-based existence by the line of hominids destined to become humans, and became the unique solution to insuring a back-up fuel supply for the expanding hominid brain. Hence, survival of the fattest (babies) was the key to human brain evolution.
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Recap:
Humans have a gut about half as large, and a brain about four times larger than our last common ancestor did (common ancestor with chimps and bonobos). During that time, nutritional environments changed to the point that physiology of the gut and the brain made a trade-off (we got littler guts and bigger brains than any other primate).
Big guts preclude the existence of big brains via nutrition science (fatty acids) and organ competition for digestible energy. Littler guts were a requirement for bigger and better thinking. When you've got a little gut, then you've got to eat and/or be born with baby fat -- so that your brain can develop differently than any other animal's brain ever could (because of their big guts).
This difference in the degree of gut size produces a discontinuous difference in brain power between humans an animals.
Ed
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