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Báo cáo sinh học: " Phenotypic and genetic variability of morphometrical traits in natural populations of Drosophila melanogaster and D simulans. I. Geographic variations"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Phenotypic and genetic variability of morphometrical traits in natural populations of Drosophila melanogaster and D simulans. I. Geographic variations | Genet Sei Evol 1993 25 517-536 @ Elsevier INRA 517 Original article Phenotypic and genetic variability of morphometrical traits in natural populations of Drosophila melanogaster and D simulans. I. Geographic variations p Capy E Pla JR David Centre National de la Recherche Scientifique Laboratoire de Biologie et Génétique Evolutives 91198 Gif-sur-Yvette Cedex France Received 30 March 1993 accepted 10 August 1993 Summary - Geographical variability between natural populations of the 2 related cosmopolitan species Drosophila melanogaster and D simulans was investigated on a large number of populations ie 55 and 25 respectively for 6 morphometrical traits concerning weight size reproductive capacity and bristle numbers. For 21 populations sympatric samples of the 2 species were available. For most traits the mean values of D melanogaster are higher than those of D simulans with the exception of the sternopleural bristle number for which the species are similar. In D melanogaster similar latitudinal variations exist along an African-European axis in both hemispheres and on the American continent. In D simulans a latitudinal cline that is parallel to those observed in D melanogaster was observed suggesting that variability between populations is partially adaptive. In addition to these parallel variations in which the mean values of all traits increase with latitude inter-continental variations were also detected in D melanogaster when populations sampled at similar latitudes were compared eg West Indian and Far Eastern populations . Different demographic strategies r or K could explain such variations. Analysis of morphological distances Mahalanobis generalized distance D2 between populations of the 2 species showed that D melanogaster is much more diversified than D simulans. All the traits except the sternopleural bristle number are involved in these differences. Drosophila melanogaster Drosophila simulans morphometrical trait geographic variability isofemale line .