Artificial selection is the intentional breeding for certain traits, or combinations of traits, over others. It was originally defined by Charles Darwin in contrast to the process of natural selection, in which the differential reproduction of organisms with certain traits is attributed to improved survival and/or reproductive ability ("Darwinian fitness") in the natural habitat of the organism. Charles Robert Darwin (February 12 1809 &ndash April 19 1882 was an English naturalist, who realised and demonstrated that all Species of life Natural selection is the process by which favorable Heritable traits become more common in successive Generations of a Population of A habitat (which is Latin for "it inhabits" is an Ecological or environmental area that is inhabited by a particular Species. Artificial selection that produces an undesirable outcome from a human perspective is sometimes called negative selection (but note that this term has a better-established meaning as a type of natural selection; see negative selection). Artificial selection can also be unintentional; it is thought that domestication of crops by early humans was largely unintentional. [1]
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Historical development
Charles Darwin coined the term as an illustration of his proposed wider process of natural selection. Charles Robert Darwin (February 12 1809 &ndash April 19 1882 was an English naturalist, who realised and demonstrated that all Species of life Darwin noted that many domesticated animals and plants had special properties that were developed by intentionally encouraging the breeding potential of individuals who both possessed desirable characteristics, and discouraging the breeding of individuals who had less desirable characteristics.
Contrast to natural selection
It should be emphasized that there is no real difference in the genetic processes underlying artificial and natural selection, and that the concept of artificial selection was first introduced as an illustration of the wider process of natural selection. The selection process is termed "artificial" when human preferences or influences have a significant effect on the evolution of a particular population or species. Indeed, many evolutionary biologists view domestication as a type of natural selection and adaptive change that occurs as organisms are brought under the control of human beings. Domestication (from Latin domesticus) refers to the process whereby a Population of Animals
Laboratory usage
The deliberate exploitation of selective power has become common in experimental biology, particularly in microbiology and genetics. Microbiology (from Greek grc μῑκρος mīkros, "small" grc βίος bios, " Life " and grc -λογία Genetics (from Ancient Greek grc-Latn genetikos, “genitive” and that from grc-Latn genesis, “origin” a discipline of Biology, is In a ubiquitous laboratory technique in genetic engineering, genes are introduced into cells in cell culture, usually bacteria, on a small circular DNA molecule called a plasmid in a process called transfection. Genetic engineering, Recombinant DNA technology, genetic modification/manipulation (GM and gene splicing are terms that apply to the direct History See also History of genetics The existence of genes was first suggested by Gregor Mendel (1822-1884 who in the 1860s studied inheritance The cell is the structural and functional unit of all known living Organisms It is the smallest unit of an organism that is classified as living and is often called Cell culture is the process by which prokaryotic, or eukaryotic cells are grown under controlled conditions The Bacteria ( singular: bacterium) are a large group of unicellular Microorganisms Typically a few Micrometres in length bacteria have Deoxyribonucleic acid ( DNA) is a Nucleic acid that contains the genetic instructions used in the development and functioning of all known A plasmid is an extra-chromosomal DNA molecule separate from the chromosomal DNA which is capable of replicating independently of the chromosomal DNA Transfection is the process of introducing nucleic acids into cells by non-viral methods. The gene of interest is accompanied on the plasmid by a reporter gene, or "selectable marker", which encodes a specific trait such as antibiotic resistance or ability to grow in high salt concentrations. In Molecular biology, a reporter gene (often simply reporter) is a Gene that researchers attach to another gene of interest in Cell culture Antibiotic resistance is the ability of a Microorganism to withstand the effects of Antibiotics. The cells can then be cultured in an environment that would kill normal cells, but is hospitable to those that have taken up and expressed the genes on the plasmid. Gene expression is the process by which inheritable information from a Gene, such as the DNA sequence, is made into a functional Gene product, such In this way expression of the reporter gene serves as a signal that the gene of interest is also being expressed in the cells.
Another technique used in drug development uses an iterative selective process called in vitro selection to evolve aptamers, or nucleic acid fragments capable of binding specific organic compounds with high binding affinity. Drug development or preclinical development is defined in many pharmaceutical companies as the process of taking a new chemical lead through the stages necessary to allow it SELEX ("Systematic Evolution of Ligands by Exponential Enrichment" also referred to as in vitro selection or in vitro evolution, is a Combinatorial Aptamers are oligonucleic acid or Peptide molecules that bind a specific target molecule A nucleic acid is a Macromolecule composed of chains of monomeric Nucleotides In Biochemistry these Molecules carry Genetic information An organic compound is any member of a large class of Chemical compounds whose Molecules contain Carbon.
Studies in evolutionary physiology, behavioral genetics, and other areas of organismal biology have also made use of deliberate artificial selection, though longer generation times and greater difficulty in breeding can make such projects challenging in vertebrates. Evolutionary physiology is the study of physiological evolution, which is to say the manner in which the functional characteristics of individuals in a population of Behavioural genetics is the field of Biology that studies the role of Genetics in Animal (including Human) Behaviour. The doubling time is the period of time required for a quantity to double in size or value [2][3]
Online experiments in artificial selection
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- Mutating Pictures
References
- ^ Artificial Selection powerpoint, University of Wisconsin-Madison
- ^ Swallow JG, Garland T. (2005). Selection experiments as a tool in evolutionary and comparative physiology: insights into complex traits—an introduction to the symposium. Integr Comp Biol, 45:387–390. PDF
- ^ Garland T. (2003). Selection experiments: an under-utilized tool in biomechanics and organismal biology. Ch. 3, Vertebrate Biomechanics and Evolution ed. Bels VL, Gasc JP, Casinos A. PDF
Related Topics
- Plant breeding
- Experimental evolution
- Gene pool
- Genetic engineering
- Inbreeding
- Marker assisted selection
- Quantitative genetics
- Selective breeding
- Smart breeding
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