title: Evolution: Causality and the Origin of Parasitism.
abstract: The first comparison of parasitic trypanosomatids to their free-living relatives reveals that some characteristics once linked to parasitism actually predate it. Parallel comparisons of other parasites suggest we need to rethink the drivers and consequences of the parasitic lifestyle.
authors.affiliation: Department of Biology, San Diego State University, San Diego, CA, USA. Electronic address: janjan.cz@gmail.com.
authors.forename: Jan
authors.initials: J
authors.lastname: Janouskovec
authors.affiliation: Department of Botany, University of British Columbia, Vancouver, BC, Canada. Electronic address: pkeeling@mail.ubc.ca.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Keeling
mesh_terms: D000818:Animals; D005075:Biological Evolution; D006790:Host-Parasite Interactions; D010271:Parasites; D013559:Symbiosis