Population structure in Daphnia obtusa: Quantitative genetic and allozymic variation

  • Spitze K
  • 274


    Mendeley users who have this article in their library.
  • 500


    Citations of this article.


Quantitative genetic analyses for body size and for life history characters within and among populations of Daphnia obtusa reveal substantial genetic variance at both hierarchical levels for all traits measured. Simultaneous allozymic analysis on the same population samples indicate a moderate degree of differentiation: GST = 0.28. No associations between electrophoretic genotype and phenotypic characters were found, providing support for the null hypothesis that the allozymic variants are effectively neutral. Therefore, GST can be used as the null hypothesis that neutral phenotypic evolution within populations led to the observed differentiation for the quantitative traits, which I call QST. The results of this study provide evidence that natural selection has promoted diversification for body size among populations, and has impeded diversification for relative fitness. Analyses of population differentiation for clutch size, age at reproduction, and growth rate indicate that neutral phenotypic evolution cannot be excluded as the cause.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Get full text


  • K. Spitze

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free