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Microevolution is the change in allele frequencies that occurs over time within a population. [1] This change is due to four different processes: mutation, selection (natural and artificial), gene flow and genetic drift. This change happens over a relatively short (in evolutionary terms) amount of time compared to the changes termed macroevolution.
Professor of biology Jerry Coyne sums up biological evolution succinctly: [3]. Life on Earth evolved gradually beginning with one primitive species – perhaps a self-replicating molecule – that lived more than 3.5 billion years ago; it then branched out over time, throwing off many new and diverse species; and the mechanism for most (but not all) of evolutionary change is natural selection.
Fossils provide evidence that accumulated changes in organisms over long periods of time have led to the diverse forms of life we see today. A fossil itself reveals the organism's structure and the relationships between present and extinct species, allowing palaeontologists to construct a family tree for all of the life forms on Earth. [42]
Evolution is the change in the heritable characteristics of biological populations over successive generations. [1] [2] It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, resulting in certain characteristics becoming more or less common within a population over successive generations. [3]
Although he wrote that societies over time progressed – and that progress was accomplished through competition – he stressed that the individual rather than the collectivity is the unit of analysis that evolves; that, in other words, evolution takes place through natural selection and that it affects social as well as biological phenomenon.
Metonymy: Change based on nearness in space or time, e.g., jaw "cheek" → "mandible". Synecdoche: Change based on whole-part relation. The convention of using capital cities to represent countries or their governments is an example of this. Hyperbole: Change from weaker to stronger meaning, e.g., kill "torment" → "slaughter"
Glen Elder theorized the life course as based on five key principles: life-span development, human agency, historical time and geographic place, timing of decisions, and linked lives. As a concept, a life course is defined as "a sequence of socially defined events and roles that the individual enacts over time" (Giele and Elder 1998, p. 22).
Conceptual change is the process whereby concepts and relationships between them change over the course of an individual person's lifetime or over the course of history. . Research in four different fields – cognitive psychology, cognitive developmental psychology, science education, and history and philosophy of science - has sought to understand this pro