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báo cáo khoa học: "Population crash, population flush and genetic variability in cage populations of Drosophila melanogaster"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Population crash, population flush and genetic variability in cage populations of Drosophila melanogaster | Génét. Sél. Evol. 1984 16 1 45-56 Population crash population flush and genetic variability in cage populations of Drosophila melanogaster F.A. LINTS and M. BOURGOIS Laboratoire de Génétique Université de Louvain 2 place Croix-du-Sud B 1348 Louvain-la-Neuve Belgium Summary A large increase in the total phenotypic variance of thorax size was observed in a cage population of Drosophila mẹlanogastẹr maintained at 28 C a few months after it had been the victim of a naturally occuring population crash the number of individuals in the population having at a given moment been reduced to half a dozen. In order to ascertain whether that increase in total phenotypic variance was due to an increase in environmental or in genetic variance that population was submitted together with five other normally developing cage populations to a selection programme for high and low bristle number. The additive genetic variance of these various populations was thereafter estimated. The additive genetic variance of the 28 C cage population victim of a population crash was found to be highly significantly larger than all the other ones. The consequences of that unexpected observation on the theories of evolution are discussed. It is argued that that result confirms some of the predictions of the genetic revolution genetic transilience hypothesis of speciation. Key words Drosophila melanogaster cage populations genetic variance speciation genetic revolution hypothesis sternopleural bristles. Resume Changements deffectifs et variabiỉité génétique dans des cages à population chez Drosophila melanogaster Un accroissement important de la variance phénotypiquẹ totale de la taille thoracique a été observe dans une cage à population de Drosophila melanogaster quelques mois après que cette population ait été victime d une reduction drastique et naturelle du nombre d individus qui la composait ce nombre ayant été réduit à environ une demi-douzaine d individus. Cet accroissement brutal de la variance .