The First Three Years Of Life - amazonia.fiocruz.br

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Obviously the first three years of life are an extraordinary and vital part of child development. Children develop from being almost entirely dependent new-borns to independent, communicating individuals who can dance, sing, and tell stories. The intuitive importance of those early years was backed up by the emergence of some intriguing neuroscience, key among which was the idea of sensitive periods. All animals studied, including humans, show sensitive periods as juveniles [ii]. A broad implication could be, wrongly, taken that this means we must learn things early or we will not learn them at all. The idea of sensitive periods is compelling, but ultimately largely irrelevant to any typical child rearing environment. The kinds of things that have been convincingly shown to have sensitive periods in humans are very basic things like depth perception, and even then the sensitive period is thought to extend to age four [iii]. In the case of language development, the most convincing sensitive period is for being able to perceive the speech sounds of a language [iv] , again quite a basic human skill. Tragically, we can consider the effects of such extreme early neglect through examples like the international adoption of children from Romanian orphanages in the early 90s after the fall of the Ceausescu regime. Institutionalisation severely effects all areas of child development; yet after adoption, recovery is not equal across different areas. The First Three Years Of Life.

In evolutionary biologyabiogenesisor informally the origin of life OoL[3] [4] [5] [a] is the natural process by which life has arisen from non-living matter, such as simple organic compounds. There are several principles and hypotheses for how abiogenesis could have occurred.

The study of abiogenesis aims to determine how pre-life chemical reactions gave rise to life under conditions strikingly different from those on Earth today. Life functions through the specialized chemistry of carbon and water and builds largely upon four key families of chemicals: lipids cell membranescarbohydrates sugars, celluloseamino acids protein metabolismand nucleic acids DNA and RNA. Any successful theory of abiogenesis must explain the origins and interactions of these classes of The First Three Years Of Life. Researchers generally think that current life descends from an RNA world[17] although other self-replicating molecules may have preceded RNA. The classic Miller—Urey experiment and similar research demonstrated that most amino acids, the chemical constituents of the proteins used in all living organisms, can be synthesized from inorganic compounds under conditions intended to replicate those of the early Earth.

Scientists have proposed various external sources of energy that may have triggered these reactions, including lightning and radiation. Other approaches "metabolism-first" hypotheses focus on understanding how catalysis in chemical systems on the early Earth might have provided the precursor molecules necessary for self-replication.

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The alternative panspermia hypothesis [21] speculates that microscopic life arose outside Earth by unknown mechanisms, and spread to the early Earth on space dust [22] and meteoroids. Earth remains the only place in the universe known to harbour life, [28] [29] and fossil evidence from the Earth informs most studies of abiogenesis. The age of the Earth is 4.

In scientists found possible evidence of early life on land in 3. As of [update]microfossils fossilised microorganisms within hydrothermal-vent precipitates dated 3.

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The NASA strategy on abiogenesis states that it is necessary to identify interactions, intermediary structures and functions, energy sources, and environmental factors that contributed to the diversity, selection, and replication of evolvable macromolecular systems. The advent of polymers The First Three Years Of Life could replicate, store genetic information, and exhibit properties subject to selection likely was a critical step in the emergence of prebiotic chemical evolution. In antiquity it was commonly thought, for instance by Empedocles and Aristotle, that the life of the individuals of some species, and more generally, life itself, could start with high temperature, i. Similarly, it was realized early on that life requires a loss of entropyor disorder, when molecules organize themselves into living matter.

University College London – Birkbeck University of London – UCL Institute of Education

This Second Law of thermodynamics needs to be considered when self-organization of matter to higher complexity happens. Because living organisms are machines, [45] the Second Law applies to life as well. Thus, contrary to a naive view of the Second Law, the emergence of life and increased complexity does not contradict this law: First, a living organism creates order in some places e. Second, the Second Law of thermodynamics actually predicts an increase in complexity [46] and in correlations between a system and its surrounding, when undergoing link [47] - with memory and genetic LLife being examples of such correlations between a living organism and its environment.]