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Adaptive mutation, also called directed mutation or directed mutagenesis is a controversial evolutionary theory. It posits that mutations , or genetic changes, are much less random and more purposeful than traditional evolution , implying that organisms can respond to environmental stresses by directing mutations to certain genes or areas of ...
For example, schizophrenia has been linked with increased creativity (Crespi et al. 2007), perhaps a useful trait for obtaining food or attracting mates in Palaeolithic times. Alternatively, the adaptive mutations may be the ones which reduce the chance of disease arising due to other mutations.
Adaptation affects all aspects of the life of an organism. [24] The following definitions are given by the evolutionary biologist Theodosius Dobzhansky: 1. Adaptation is the evolutionary process whereby an organism becomes better able to live in its habitat or habitats. [25] [26] [27] 2.
In cell biology and pathophysiology, cellular adaptation refers to changes made by a cell in response to adverse or varying environmental changes. The adaptation may be physiologic (normal) or pathologic (abnormal). Morphological adaptations observed at the cellular level include atrophy, hypertrophy, hyperplasia, and metaplasia. [1]
The mechanisms of evolution focus mainly on mutation, genetic drift, gene flow, non-random mating, and natural selection. Mutation: Mutation [12] is a change in the DNA sequence inside a gene or a chromosome of an organism. Most mutations are deleterious, or neutral; i.e. they can neither harm nor benefit, but can also be beneficial sometimes.
Evolutionary physiology is the study of the biological evolution of physiological structures and processes; that is, the manner in which the functional characteristics of organisms have responded to natural selection or sexual selection or changed by random genetic drift across multiple generations during the history of a population or species. [2]
Ecological genetics is the study of genetics in natural populations. It combines ecology, evolution, and genetics to understand the processes behind adaptation. [1] It is virtually synonymous with the field of molecular ecology.
Adaptationism is an approach to studying the evolution of form and function. It attempts to frame the existence and persistence of traits, assuming that each of them arose independently and improved the reproductive success of the organism's ancestors.