Search results
Results From The WOW.Com Content Network
Molecular evolution describes how inherited DNA and/or RNA change over evolutionary time, and the consequences of this for proteins and other components of cells and organisms. Molecular evolution is the basis of phylogenetic approaches to describing the tree of life. Molecular evolution overlaps with population genetics, especially on shorter ...
Molecular breeding is the application of molecular biology tools, often in plant breeding [1] [2] and animal breeding. [3] [4] In the broad sense, molecular breeding can be defined as the use of genetic manipulation performed at the level of DNA to improve traits of interest in plants and animals, and it may also include genetic engineering or gene manipulation, molecular marker-assisted ...
Plant breeding can be performed using many different techniques, ranging from the selection of the most desirable plants for propagation, to methods that make use of knowledge of genetics and chromosomes, to more complex molecular techniques. Genes in a plant are what determine what type of qualitative or quantitative traits it will have.
DNA shuffling by molecular breeding was first reported in 1994 by Willem P.C. Stemmer. [1] [7] He started by fragmenting the β-lactamase gene that had been amplified with the polymerase chain reaction (PCR) by using DNase I, which randomly cleaves DNA.
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]
The idea of evolution by natural selection was proposed by Charles Darwin in 1859, but evolutionary biology, as an academic discipline in its own right, emerged during the period of the modern synthesis in the 1930s and 1940s. [8]
While some degree of gene flow occurs in the course of normal evolution, hybridization with or without introgression may threaten a rare species' existence. [20] [21] For example, the Mallard is an abundant species of duck that interbreeds readily with a wide range of other ducks and poses a threat to the integrity of some species.
Molecular evolution in general—and the molecular clock in particular—offered little basis for exploring evolutionary causation. According to the molecular clock hypothesis, proteins evolved essentially independently of the environmentally determined forces of selection; this was sharply at odds with the panselectionism prevalent at the time.