• DOI:10.1086/281977
• Corpus ID: 83886607

Endogenous Rhythms in Insects and Microorganisms

@article{Bruce1957EndogenousRI,
  title={Endogenous Rhythms in Insects and Microorganisms},
  author={Victor G. Bruce and Colin Stephenson Pittendrigh},
  journal={The American Naturalist},
  year={1957},
  volume={91},
  pages={179 - 195}
}

• V. Bruce, C. Pittendrigh
• Published 1 May 1957
• Biology
• The American Naturalist

Twenty-four hour rhythms in organisms may be considered to be the rule rather than the exception. It is likewise the rule that such rhythms persist under constant conditions of light and temperature in the laboratory. This feature led sometime ago to their description as "persistent" rhythms or "endogenous" rhythms. The latter phrase carries the implication that the observed periodicity of organic activity is independent of those "Residual Periodic Variables," (cf. Pittendrigh, 1957; Pittendrigh and Bruce, 1957) such as: air pressure, cosmic ray intensity, etc., that remain uncontrolled in the usual laboratory analysis. There is a further implication in describing persistent rhythms as endogenous: the observed periodicity is taken to reflect the organisms's capacity to measure absolute time. Thus, in recent years thinking about endogenous rhythms has become oriented by the deduction that organisms possess clocks as part of their overall adaptive or-