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Gene duplication (or chromosomal duplication or gene amplification) is a major mechanism through which new genetic material is generated during molecular evolution. It can be defined as any duplication of a region of DNA that contains a gene .
Evolution by gene duplication is an event by which a gene or part of a gene can have two identical copies that can not be distinguished from each other. This phenomenon is understood to be an important source of novelty in evolution, providing for an expanded repertoire of molecular activities.
It is called the Gene Duplication problem or more generally Gene Tree parsimony. The problem was seen as a way to detect paralogy to get better species tree reconstruction. [ 108 ] [ 109 ] It is NP-hard, with interesting results on the problem complexity [ 91 ] [ 110 ] and the behaviour of the model with different input size, structure and ILS ...
The 2R hypothesis or Ohno's hypothesis, first proposed by Susumu Ohno in 1970, [1] is a hypothesis that the genomes of the early vertebrate lineage underwent two whole genome duplications, and thus modern vertebrate genomes reflect paleopolyploidy.
Copy number variation was initially thought to occupy an extremely small and negligible portion of the genome through cytogenetic observations. [12] Copy number variations were generally associated only with small tandem repeats or specific genetic disorders, [13] therefore, copy number variations were initially only examined in terms of specific loci.
Single gene duplication is a random process and tends to make duplicated genes scattered throughout the genome. Duplicated blocks are non-overlapping because they were created simultaneously. Segmental duplication within the genome can fulfill the first rule; but multiple independent segmental duplications could overlap each other. [18]
A gene family is a set of several similar genes, formed by duplication of a single original gene, and generally with similar biochemical functions. One such family are the genes for human hemoglobin subunits; the ten genes are in two clusters on different chromosomes, called the α-globin and β-globin loci.
The principal forces of evolution in prokaryotes and their effects on archaeal and bacterial genomes. The horizontal line shows archaeal and bacterial genome size on a logarithmic scale (in megabase pairs) and the approximate corresponding number of genes (in parentheses).The effects of the main forces of prokaryotic genome evolution are denoted by triangles that are positioned, roughly, over ...