Search results
Results From The WOW.Com Content Network
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.
Two useful introductions to the fundamental theory underlying the unit of selection issue and debate, which also present examples of multi-level selection from the entire range of the biological hierarchy (typically with entities at level N-1 competing for increased representation, i.e., higher frequency, at the immediately higher level N, e.g., organisms in populations or cell lineages in ...
Setting aside other factors (e.g., balancing selection, and genetic drift), the equilibrium number of deleterious alleles is then determined by a balance between the deleterious mutation rate and the rate at which selection purges those mutations. Mutation–selection balance was originally proposed to explain how genetic variation is ...
Also called functionalism. The Darwinian view that many or most physiological and behavioral traits of organisms are adaptations that have evolved for specific functions or for specific reasons (as opposed to being byproducts of the evolution of other traits, consequences of biological constraints, or the result of random variation). adaptive radiation The simultaneous or near-simultaneous ...
However, after a period with no new mutations, the genetic variation at these sites is eliminated due to genetic drift. Natural selection reduces genetic variation by eliminating maladapted individuals, and consequently the mutations that caused the maladaptation. At the same time, new mutations occur, resulting in a mutation–selection ...
[c] [20] [21] By this, de Vries meant that a new form of the plant was created in a single step (not the same as a mutation in the modern sense); no long period of natural selection was required for speciation, and nor was reproductive isolation. [22] In the view of the historian of science Peter J. Bowler, De Vries used the term to mean [1]
Genetics – Science of genes, heredity, and variation in living organisms; Biogeography – Study of distribution of species; Ecological genetics – Study of genetics in natural populations; Evolutionary biology – Study of the evolution of life Evolutionary developmental biology – Comparison of organism developmental processes
The basis for selection is the quality of an individual, which is determined by the fitness function. In memetic algorithms, an extension of EA, selection also takes place in the selection of those offspring that are to be improved with the help of a meme (e.g. a heuristic).