Conflicting processes in the evolution of body size and development time

H. Frederik Nijhout, Derek A. Roff, Goggy Davidowitz

Research output: Contribution to journalArticlepeer-review

65 Scopus citations


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.

Original languageEnglish (US)
Pages (from-to)567-575
Number of pages9
JournalPhilosophical Transactions of the Royal Society B: Biological Sciences
Issue number1540
StatePublished - Feb 27 2010


  • Body size
  • Growth
  • Manduca sexta
  • Mathematical model
  • Morphospace
  • Selection

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)


Dive into the research topics of 'Conflicting processes in the evolution of body size and development time'. Together they form a unique fingerprint.

Cite this