Conflicting processes in the evolution of body size and development time.


Journal Article

Body size and development time of Manduca sexta are both determined by the same set of three developmental-physiological factors. These define a parameter space within which it is possible to analyse and explain how phenotypic change is associated with changes in the underlying factors. Body size and development time are determined by the identical set of underlying factors, so they are not independent, but because the mechanisms by which these factors produce each phenotype are different, the two phenotypes are only weakly correlated, and the correlation is context dependent. We use a mathematical model of this mechanism to explore the association between body size and development time and show that the correlation between these two life-history traits can be positive, zero or negative, depending entirely on where in parameter space a population is located, and on which of the underlying factors has a greater variation. The gradient within this parameter space predicts the unconstrained evolutionary trajectory under directional selection on each trait. Calculations of the gradients for body size and development time revealed that these are nearly orthogonal through much of the parameter space. Therefore, simultaneous directional selection on body size and development time can be neither synergistic nor antagonistic but leads to conflicting selection on the underlying developmental parameters.

Full Text

Duke Authors

Cited Authors

  • Nijhout, HF; Roff, DA; Davidowitz, G

Published Date

  • February 2010

Published In

Volume / Issue

  • 365 / 1540

Start / End Page

  • 567 - 575

PubMed ID

  • 20083633

Pubmed Central ID

  • 20083633

Electronic International Standard Serial Number (EISSN)

  • 1471-2970

International Standard Serial Number (ISSN)

  • 0962-8436

Digital Object Identifier (DOI)

  • 10.1098/rstb.2009.0249


  • eng