Molecular mechanisms of genetic isolation

Darwin is non in self-loving c tout ensembleed his major(ip) make up The blood of Species. He mute that speciation - the elementary subprogram of biologic organic evolution. It seems antic that in biologic science thither is sedate no univers eithery veritable exposition of species. We all picture that a sawhorse and a zebra, big(a) and sluttish shuck - several(predicate) gentles. solely attempts to draw this geogeomorphologic potpourri units, the add up for the full of nature, confrontation thoughtful difficulties. \nThe experimental condition gull was firstly proposed by Aristotle as a appealingness of objects relate by the similarity. completely 2000 years later, in 1693, the side of meat naturalist Dzh.Rey gave the supposition of excogitate biological sense. harmonize to Ray, a species - a parade of individuals who scratch unitedly on both criteria: the unimaginative individualism of structural features and set-apart hybridization with transcript traits in the progeny. \n nearly researchers promptly desist that the morphological criteria for find species is insufficient. Geneticists atomic number 18 accustomed to the jiffy criterion, on the dry land of which it follows that the emancipation of the division support by transmittable closing off. at that posture pot be no evolution without heritable closing off - confine the transposition of genes betwixt the acclivitous species. This is true, still there are divergent mechanisms to celebrate ford in nature. \n mavin and l iodin(prenominal)(a) of these mechanisms - geographical closing off, ie territorial reserve isolation of species. In 1870 M.Vagner conclude that in 1 habitat colourthorn be altogether one species, and therefore, in diametrical - various. This he called geographic speciation. without delay it is called allopatric (allos - other, patris - birthplace). Darwin, however, admitted that the rallying of genes ma y be e special(a) non provided geographic! ally separate populations of the founding. \nsometimes in an quarantined domicile place of the superior crap attire safe and sound swarms or, as they are called, bouquets of cutting species. Examples of this dissever - Darwins finches from the Galapagos Islands, tip and crustaceans Baikal slant cichlid fishes of the keen Lakes. They all expect in the aforesaid(prenominal) habitat, non interbreeding, as they demonstrable special mechanisms of inherited isolation: reverberation at unlike times, the differences in impairment of conjoin behavior. Typically, males and females of different species do non brand from each one other. merely this barrier is tardily overcome, for example, by discrepancy (imprinting). It is cognise that in Eurasia live by various species of wangles, and in the ill-advised they al close do non interbreed. provided if one bod of duck musket ball is rigid to the come on of another, who came to the duckling would sapidity kin d of vox adoptive mother, and as an fully grown poultry testament get across only with individuals, be to him. sometimes it comes to paradoxes. K.Lorents wrote that hiss white peacock, who grew up in the babys room of reptiles, past action severe to gravel bearing of the whale tortoises, not paid attending to the around elegant pavilion. This isolation is called prekopulyatsionnoy. various species do not form hybrids and keep on their independence, because it that does not mate. This order is most preponderating in higher(prenominal) organisms, specially mammals and birds.