Journal of Biosciences

, Volume 28, Issue 4, pp 523–528

On the origin of differentiation

  • J. T. Bonner
Article

Abstract

Following the origin of multicellularity in many groups of primitive organisms there evolved more than one cell type. It has been assumed that this early differentiation is related to size — the larger the organism the more cell types. Here two very different kinds of organisms are considered: the volvocine algae that become multicellular by growth, and the cellular slime moulds that become multicellular by aggregation. In both cases there are species that have only one cell type and others that have two. It has been possible to show that there is a perfect correlation with size: the forms with two cell types are significantly larger than those with one. Also in both groups there are forms of intermediate size that will vary from one to two cell types depending on the size of the individuals, suggesting a form of quorum sensing. These observations reinforce the view that size plays a critical role in influencing the degree of differentiation.

Keywords

Cellular slime moulds quorum sensing size Volvox 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Bell G and Mooers 1997 Size and complexity among multicellular organisms;J. Linn. Soc. 60 345–363CrossRefGoogle Scholar
  2. Bonner J T 1988The evolution of complexity (Princeton: Princeton University Press)Google Scholar
  3. Bonner J T 2000First signals (Princeton: Princeton University Press)Google Scholar
  4. Bonner J T 2003 The evolution of development in the cellular slime moulds;Evol. Dev. (in press)Google Scholar
  5. Bonner J T and Dodd M R 1962 Aggregation territories in the cellular slime moulds;Biol. Bull. 122 13–24CrossRefGoogle Scholar
  6. Gadagkar R and Bonner J T 1994 Social insects and social amoebae;J. Biosci. 19 219–245CrossRefGoogle Scholar
  7. Kirk D 1998Volvox (Cambridge: Cambridge University Press)Google Scholar
  8. Kirk D 2001 Germ-soma differentiation inVolvox;Dev. Biol. 238 213–223PubMedCrossRefGoogle Scholar
  9. Moore H, Dvorakova K, Jenkins N and Breed W 2002 Exceptional sperm cooperation in the wood mouse;Nature (London) 418 174–177CrossRefGoogle Scholar
  10. Olive L S 1975The mycetozoans (New York: Academic Press)Google Scholar
  11. Pfeiffer T and Bonhoeffer S 2003 An evolutionary scenario for the transition to undifferentiated multicellularity;Proc. Natl. Acad. Sci. USA 100 1095–1098PubMedCrossRefGoogle Scholar
  12. Raper K 1984The Dictyostelids (Princeton: Princeton University Press)Google Scholar

Copyright information

© Indian Academy of Sciences 2003

Authors and Affiliations

  • J. T. Bonner
    • 1
  1. 1.Department of Ecology and Evolutionary BiologyPrinceton UniversityPrincetonUSA

Personalised recommendations