01775naa a2200253 a 450000100080000000500110000800800410001910000200006024501910008026000090027152009960028065000290127665000130130565000140131865000160133265300200134865300190136865300230138765300220141065300160143265300190144870000170146777300370148417955741999-05-04       1966    bl ---       0--  u    #d1 aLEWONTIN, R. C.  aA molecular approach to the study of genic heterozygosity in natural populations. II. Amount of variation and degree of heterozygosity in natural populations of Drosophila pseudoobscura.  c1966  aAs pointed out in the first paper of this series (Hubby and Lewontin 1966), no one knows at the present time the kinds and frequencies of variant alleles present in natural populations of any organism, with the exception of certain special classes of genes. For human populations we know a good deal about certain polymorphisms for blood cell antifens, serum proteins, and metabolic disorders of various kinds but we can hardly regard theses, a priori, as typical of the genome as a whole. Clearly we need a method that will randomly sample the genome and detect a major proportion of the individual allelic substitutions that are segregating in a population. In our previous paper, we discussed a method for accomplishing this end by means of a study of electrophoretic variants at a large number of loci and we showed that the variation picked up by this method behaves in a simple Mendelin fashion so that phenotypes can be equated to hemozygous and heterozygous genotypes at single loci.  aDrosophila pseudoobscura  agenetics  aGenética  aPopulação  aEstudo genetico  aMosca-da-fruta  aNatural population  aPopulacao natural  aPopulations  aStudy of genic1 aHUBBY, J. L.  tGeneticsgv.54, p.595-609, 1966.