title: An evolutionary approach to Function.
abstract: BACKGROUND
  Understanding the distinction between function and role is vexing and difficult. While it appears to be useful, in practice this distinction is hard to apply, particularly within biology.
  
  
  RESULTS
  I take an evolutionary approach, considering a series of examples, to develop and generate definitions for these concepts. I test them in practice against the Ontology for Biomedical Investigations (OBI). Finally, I give an axiomatisation and discuss methods for applying these definitions in practice.
  
  
  CONCLUSIONS
  The definitions in this paper are applicable, formalizing current practice. As such, they make a significant contribution to the use of these concepts within biomedical ontologies.
authors.affiliation: School of Computing Science, Newcastle University, Newcastle-Upon-Tyne, NE1 7RU, UK. phillip.lord@newcastle.ac.uk.
authors.forename: Phillip
authors.initials: P
authors.lastname: Lord