Biology & Philosophy

, Volume 31, Issue 6, pp 875–892 | Cite as

Holobionts and the ecology of organisms: Multi-species communities or integrated individuals?

  • Derek SkillingsEmail author


It is now widely accepted that microorganisms play many important roles in the lives of plants and animals. Every macroorganism has been shaped in some way by microorganisms. The recognition of the ubiquity and importance of microorganisms has led some to argue for a revolution in how we understand biological individuality and the primary units of natural selection. The term “holobiont” was introduced as a name for the biological unit made up by a host and all of its associated microorganisms, and much of this new debate about biological individuality has focused on whether holobionts are integrated individuals or communities. In this paper, I show how parts of the holobiont can span both characterizations. I argue that most holobionts share more affinities with communities than they do with organisms, and that, except for maybe in rare cases, holobionts do not meet the criteria for being organisms, evolutionary individuals, or units of selection.


Holobiont Symbiosis Individuality Organism Bacteria Microbe 



This paper found its impetus in conversations with Austin Booth and many of the ideas were worked out in discussion with him. I also thank Peter Godfrey-Smith, Jessie McCormack, Maureen O’Malley, Thomas Pradeu, the participants of the 2015 Philosophy of Biology at Dolphin Beach workshop, and three anonymous reviewers for their help and useful comments.


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Copyright information

© Springer Science+Business Media Dordrecht 2016

Authors and Affiliations

  1. 1.Philosophy ProgramThe Graduate Center, CUNYNew YorkUSA
  2. 2.University of Bordeaux/CNRSUMR5164BordeauxFrance

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