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A behaviour mutation is a genetic mutation that alters genes that control the way in which an organism behaves, causing their behavioural patterns to change. A genetic mutation is a change or error in the genomic sequence of a cell. It can occur during meiosis or replication of DNA, as well as due to ionizing or UV radiation, transposons, mutagenic chemicals, viruses and a number of other factors. Mutations usually (but not always) result in a change in an organisms fitness. These changes are largely deleterious, having a negative effect on fitness; however, they can also be neutral and even advantageous.〔 It is theorized that these mutations, along with genetic recombination, are the raw material upon which natural selection can act to form evolutionary processes. This is due to selection's tendency to "pick and choose" mutations which are advantageous and pass them on to an organism's offspring, while discarding deleterious mutations. In asexual lineages, these mutations will always be passed on, causing them to become a crucial factor in whether the lineage will survive or go extinct.〔 One way that mutations manifest themselves is behaviour mutation. Some examples of this could be variations in mating patterns, increasingly aggressive or passive demeanor, how an individual learns and the way an individual interacts and coordinates with others. Behaviour mutations have important implications on the nature of the evolution of animal behaviour. They can help us understand how different forms of behaviour evolve, especially behaviour which can seem strange or out of place. In other cases, they can help us understand how important patterns of behaviour were able to arise – on the back of a simple gene mutation. Finally, they can help provide key insight on the nature of speciation events which can occur when a behaviour mutation changes the courtship methods and manner of mating in sexually reproducing species. == History == Ethology, the study of animal behaviour, has been a topic of interest since the 1930s. The pioneers of the field include great names such as Dutch biologist Nikolaas Tinbergen and Austrian biologists Karl von Frisch and Konrad Lorenz (the three won the Nobel Prize in Physiology or Medicine in 1973 for their discoveries concerning organization and elicitation of individual and social behaviour patterns).〔(【引用サイトリンク】title=The Nobel Prize in Physiology or Medicine 1973 )〕 However, the first published demonstration of how a mutation in a single gene could change an organism's behaviour was carried out by Margaret Bastock in 1956, while she was a Ph.D. student working under Tinbergen at Oxford University.〔 Bastock investigated the yellow mutant of ''Drosophila melanogaster'', the common house fly. Upon comparison of courtship rituals in 19 yellow mutants and 19 wild types, wild types were noted to court 92% of the time, while yellow ones courted only 83% of the time. In addition, when the yellow mutants courted it took them noticeably longer than the wild types. Even after significant generations of crossing, the flies homozygous for the "yellow" allele were less successful in mating with wild type females than their heterozygous brothers. These results led Bastock to conclude that the origin of this deficient mating behaviour was the very same mutant gene that caused yellow discolouration.〔 Bastock's work directly and indirectly influenced a new way of observing behaviour patterns and analyzing them, as well as changed the way we look at the evolution of these behavioural patterns in animals.〔〔 However, it was not until much later that her work was fully recognized and accredited in further studies on genes influencing animal behaviour.〔 Seymour Benzer worked further on ''D. melanogaster'' in the 1960s, focusing on different novel phenotypes such as phototaxis and circadian rhythms. In 1978, J.C. Hall returned to a similar focus on courtship while investigating different mutations. Bastock's work had important consequences for the field of neuroscience as well, spurring the emergence of neurogenetics and a new understanding of how our brains work. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Behavior mutation」の詳細全文を読む スポンサード リンク
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