Statistical genetics of an annual plant, Impatiens capensis. II. Natural selection.

Journal Article (Journal Article)

Measurement of natural selection on correlated characters provides valuable information on fitness surfaces, patterns of directional, stabilizing, or disruptive selection, mechanisms of fitness variation operating in nature, and possible spatial variation in selective pressures. We examined effects of seed weight, germination date, plant size, early growth, and late growth on individual fitness. Path analysis showed that most characters had direct or indirect effects on individual fitness, indicating directional selection. For most early life-cycle characters, indirect effects via later characters exceed the direct causal effect on fitness. Selection gradients were uniform across the experimental site. There was no evidence for stabilizing or disruptive selection. We discuss several definitions of stabilizing and disruptive selection. Although early events in the life of an individual have important causal effects on subsequent characters and fitness, there is no detectable genetic variance for most of these characters, so little or no genetic response to natural selection is expected.

Full Text

Duke Authors

Cited Authors

  • Mitchell-Olds, T; Bergelson, J

Published Date

  • February 1990

Published In

Volume / Issue

  • 124 / 2

Start / End Page

  • 416 - 421

PubMed ID

  • 2307362

Pubmed Central ID

  • PMC1203933

Electronic International Standard Serial Number (EISSN)

  • 1943-2631

International Standard Serial Number (ISSN)

  • 0016-6731


  • eng