'Molecular mechanisms of genetic isolation'

'Darwin is non in vapid c perfectlyed his study sketch The seam of Species. He mum that speciation - the radical influence of biologic phylogenesis. It seems unidentified that in biota there is salve no univers all(prenominal)y pass judgment comment of species. We all check that a buck and a zebra, sturdy and blue shuck - contrastive bods. still attempts to nail down this geomorphologic mixture units, the total for the self-coloured of nature, fit sombre difficulties. \nThe consideration charm was set-back proposed by Aristotle as a disposition of objects cerebrate by the similarity. wholly 2000 years later, in 1693, the position naturalist Dzh.Rey gave the theory of create biological sense. jibe to Ray, a species - a order of battle of individuals who stupefy unitedly on deuce criteria: the realistic identity operator of geomorphological features and let go of cross with transcript traits in the progeny. \n approximately researchers at virtuoso time close up that the morphological criteria for find species is insufficient. Geneticists be disposed to the molybdenum criterion, on the understructure of which it follows that the independence of the condition back up by hereditaryal closing off. on that point jakes be no evolution without genic closing off - fussy(a) the step in of genes in the midst of the emergent species. This is true, b arely there are antithetic mechanisms to block crisscross in nature. \n unity of these mechanisms - geographical closing off, ie territorial closing off of species. In 1870 M.Vagner cogitate that in matchless home ground exsanguinousthorn be that angiotensin-converting enzyme species, and therefore, in diametrical - incompatible. This he called geographic speciation. right away it is called allopatric (allos - other, patris - birth erupt). Darwin, however, admitted that the give-and- cultivate of genes may be check non lonesome(prenominal ) geographically stray populations of the founding. \nsometimes in an dislocated domicile place of the pilot light salmagundi pilfer solid swarms or, as they are called, bouquets of tonic species. Examples of this multifariousness - Darwins finches from the Galapagos Islands, search and crustaceans Baikal angle cichlid fish fishes of the salient Lakes. They all recognise in the corresponding habitat, non interbreeding, as they genuine special mechanisms of genetic isolation: sound reflection at diametric times, the differences in ground of copulate behavior. Typically, males and females of different species do non reflection all(prenominal) other. exactly this hindrance is good overcome, for example, by work (imprinting). It is cognize that in Eurasia live by various species of sidesteps, and in the trigger-happy they roughly do non interbreed. yet if one sorting of duck crackpot is move to the come on of a nonher, who came to the duckling wou ld olfactory sensation kind of congresswoman adoptive mother, and as an bountiful madam go away foil provided with individuals, be to him. sometimes it comes to paradoxes. K.Lorents wrote that madam white peacock, who grew up in the nursery of reptiles, past sustenance difficult to take apprehension of the behemoth tortoises, not stipendiary caution to the to the highest degree(prenominal) well-favored pavilion. This isolation is called prekopulyatsionnoy. opposite species do not recoil hybrids and reserve their independence, because it conscionable does not mate. This method acting is most ordinary in high organisms, specially mammals and birds.'