Experimental evolution is the use of laboratory experiments or controlled field manipulations to explore evolutionary dynamics. Evolution may be observed in the laboratory as individuals/populations adapt to new environmental conditions by natural selection.
There are two different ways in which adaptation can arise in experimental evolution. One is via an individual organism gaining a novel beneficial mutation. The other is from allele frequency change in standing genetic variation already present in a population of organisms. Other evolutionary forces outside of mutation and natural selection can also play a role or be incorporated into experimental evolution studies, such as genetic drift and gene flow.
The organism used is decided by the experimenter, based on the hypothesis to be tested. Many generations are required for adaptive mutation to occur, and experimental evolution via mutation is carried out in viruses or unicellular organisms with rapid generation times, such as bacteria and asexual clonal yeast. Polymorphic populations of asexual or sexual yeast, and multicellular eukaryotes like Drosophila, can adapt to new environments through allele frequency change in standing genetic variation. Organisms with longer generations times, although costly, can be used in experimental evolution. Laboratory studies with foxes and with rodents (see below) have shown that notable adaptations can occur within as few as 10–20 generations and experiments with wild guppies have observed adaptations within comparable numbers of generations.
More recently, experimentally evolved individuals or populations are often analyzed using whole genome sequencing, an approach known as Evolve and Resequence (E&R). E&R can identify mutations that lead to adaptation in clonal individuals or identify alleles that changed in frequency in polymorphic populations, by comparing the sequences of individuals/populations before and after adaptation. The sequence data makes it possible to pinpoint the site in a DNA sequence that a mutation/allele frequency change occurred to bring about adaptation.
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Directed evolution (DE) is a method used in protein engineering that mimics the process of natural selection to steer proteins or nucleic acids toward a user-defined goal. It consists of subjecting a gene to iterative rounds of mutagenesis (creating a library of variants), selection (expressing those variants and isolating members with the desired function) and amplification (generating a template for the next round). It can be performed in vivo (in living organisms), or in vitro (in cells or free in solution).
In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the population during that process. Thirdly, it is a phenotypic trait or adaptive trait, with a functional role in each individual organism, that is maintained and has evolved through natural selection. Historically, adaptation has been described from the time of the ancient Greek philosophers such as Empedocles and Aristotle.
'Charles Robert Darwin' (ˈdɑrwɪn ; 12 February 1809 – 19 April 1882) was an English naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all species of life have descended from a common ancestor is now generally accepted and considered a fundamental concept in science. In a joint publication with Alfred Russel Wallace, he introduced his scientific theory that this branching pattern of evolution resulted from a process he called natural selection, in which the struggle for existence has a similar effect to the artificial selection involved in selective breeding.
The course covers the regulation of gene expression, which translates the information contained in the genome into function, by adjusting the levels and activities of mRNAs and proteins to the needs o
Explores bacterial evolution, symbiotic relationships, adaptation to extreme environments, and impact on human health.
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In this study, we develop and apply a directed evolution approach to engineer the optical sensing properties of DNA-wrapped single-walled carbon nanotubes (DNA-SWCNTs) towards mycotoxins, a class of molecules critical to detect in the food industry. We suc ...
Background: Reproductive isolation can result from adaptive processes (e.g., ecological speciation and mutation-order speciation) or stochastic processes such as "system drift" model. Ecological speciation predicts barriers to gene flow between populations ...
Many salmonids, including brown trout (Salmo trutta), demonstrate alternative migration strategies under different environmental conditions, and as such, they are assumed to be predominantly facultative. Through experimental breeding for two generations, w ...