by Freddy Plaza
One of the major topics of controversy is about man's evolution in recent years, namely the origin of man, as we know the studies of physical anthropology shows us that modern man comes from Africa in north-eastern region near what is now known as the Horn of Africa, whose discovery was made by the paleo-anthropologist Mary Leakey, the most complete fossil of Lucy is an Australopithecus dating from about 3.8 to 4 million years, together with other discovery Ears Haeckel in 1856 published the tree of human evolution, this occurs with the emergence of primates, according to studies, was about 65 million years.
Although it is unclear when that separate our ancestor and say, orangutans, chimpanzees and bonobos, but anthropologists assume that was done about 5 to 8 million years, studies of the human genome shows that we share 99% of genes with the chimpanzee and the bonobo, the difference in the genome of any individual is 0.2%, we all have a common mother, African Eve, who lived in what today would be areas of Kenya and Ethiopia.
The concept of race has been of great debate among anthropologists, biologists, to refer to human groups by their physical differences-anatomic biogenetically talking that races do not exist, since the human species is composed of a single race (one race is a recognizable group that is part of a species, a monotypic species has no races, or rather a race contains all the species homo sapiens).
theory and social Darwinism, its agent Spencer influenced by Darwin and Lamarck, wherein said organisms evolved, adapting to the environment, ie more action survives, analyzes society as a body, is evolving to more complex forms both individual and social level, being a deterministic and elitist accepting that the social, cultural and economic Occurs through biological deference indicating that disadvantaged groups have no chance to survive, and that there should be no intervention by the Government
The Middle Paleolithic Neanderthal man appears, the discussion that arose was whether there was a relationship with Homo sapiens, although the response would be that if there was a relationship, but did not influence the appearance of modern man, the remarkable differences with the new species that survived was in morphology and anatomy befell their extinction about 30,000 years ago, causes by their low adaptive capacity.
The new species that conquered the world was the kind that we all belong, this species appeared about 200,000 years ago, there were significant changes in cranial volume 1,500 to 1,600 cm3, the evolution is done to check apart from fossil carbon-14 studies, and brain evolution (changing by natural selection) by different bodies which called MacLean triune brain (there are three very different mentalities brainstem, the limbic system and neocortex, here is checked for years produced changes), the brain had an extraordinary change from Australopithecus homo sapiens sapiens that tripled in size over 4 million years. Strong obstacle
stand the evolution of Homo sapiens sapiens species that through cognition was adapted to the environment, the most important phenomenon is undoubtedly the bipedalism (where there was morphological, metabolic, cerebral, visual), this new position to absorb the heat gender, stereoscopic vision and energy savings, which she used the brain (Arsuaga, 2004).
The existence of these changes, so did the birth, being more painful, because the opening of the pelvis is narrow at this event, there was something that did not exist, was the collaboration of others, the cognitive took shape, to appear, first production of the hunting tools, and a thought symbolic, if; we are comparing the size of the brain to the body there is a noticeable difference, the brain is 7 times larger than the body resulting in a saving metabolic energy that allows bipedal gait. For Mithen existed
cognition that our ancestors possessed three major mental modules, one related to the development of tools called technical module, one related to the knowledge of nature and the social module, allowing interaction with others (here is taken from the studies of Alexander Luria who speaks that cognition is located in different areas of the brain) and from the emergence of language enabled the integration of the three modules, as for many scientists believe that these modules do not appear equally in Australopithecus, Homo habilis, Homo sapiens sapiens, only the latter is what is called cognitive fluidity ( is the ease of information flow from one module to another, resulting in compression of material and non material world (Martin-Loeches).
Mario Bunge For there are three forms of cognition that very significant difference that can be behavioral, perceptual, conceptual, the first related to the movements of some kind, the second with the network of statutes and the third with the systems of concepts as a brain process, he wonders why the human cognitive power, three scenarios presented here are a response would be for brain plasticity (the ability of the CNS to change its composition or its organization as well as to modify some functions (activities)), which is superior to other animals with CNS (central nervous system), another possible response is the dendritic arborization of neurons, this is related to the above, and the last answer is brain lateralization ( evolution has endowed the brain of de-duplicating functions, allowing the use of 1,300 cm3 of brain mass.
This is associated with the ability to store information in the brain that is ten billion bits per cubic centimeter, a little more than any computer which shows how complex the brain in relation to its evolution, the average weight of brain tissue of modern man is of 1,375 grams
cultural transmission, allows the control of different environments occupied by the species homo sapiens sapiens, in different generations through language (enculturation), events of great significance were embodied what calls rock art, before conquering the world around us was what Karl Popper called the World 1 (would the geno-chronological units pre-cámbirca, Paleozoic and Mesozoic) was what he defines the nature, then comes the World 2 (is the Cenozoic Era, particularly in the Quaternary period) here comes the species homo and objective world and subjective their co-evolution results in the World 3, the productions (the present age.)
0 comments:
Post a Comment