Evolution of morphological integration. I. Functional units channel stress-induced variation in shrew mandibles.

  • Badyaev A
  • Foresman K
  • 140

    Readers

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

    Citations of this article.

Abstract

Stress-induced deviations from normal development are often assumed to be random, yet their accumulation and expression can be influenced by patterns of morphological integration within an organism. We studied within-individual developmental variation (fluctuating asymmetry) in the mandible of four shrew species raised under normal and extreme environments. Patterns of among-individual variation and fluctuating asymmetry were strongly concordant in traits that were involved in the attachment of the same muscles (i.e., functionally integrated traits), and fluctuating asymmetry was closely integrated among these traits, implying direct developmental interactions among traits involved in the same function. Stress-induced variation was largely confined to the directions delimited by functionally integrated groups of traits in the pattern that was concordant with species divergence--species differed most in the same traits that were most sensitive to stress within each species. These results reveal a strong effect of functional complexes on directing and incorporating stress-induced variation during development and might explain the historical persistence of sets of traits involved in the same function in shrew jaws despite their high sensitivity to environmental variation.

Author-supplied keywords

  • Animals
  • Biological Evolution
  • Biometry
  • Diet
  • Environment
  • Female
  • Male
  • Mandible
  • Mandible: anatomy & histology
  • Mandible: physiology
  • Mastication
  • Mastication: physiology
  • Shrews
  • Shrews: anatomy & histology
  • Stress, Mechanical

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

Authors

Error loading document authors.

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free