title: The hybrid nature of the Eukaryota and a consilient view of life on Earth.
abstract: The origin of the eukaryotic cell, which is known as eukaryogenesis, has puzzled scientists for more than 100 years, and many hypotheses have been proposed. Recent analyses of new data enable the safe elimination of some of these hypotheses, whereas support for other hypotheses has increased. In this Opinion article, we evaluate the available theories for their compatibility with empirical observations and conclude that cellular life consists of two primary, paraphyletic prokaryotic groups and one secondary, monophyletic group that has symbiogenic origins - the eukaryotes.
authors.affiliation: Bioinformatics and Molecular Evolution Unit, Department of Biology, National University of Ireland, Maynooth, County Kildare, Ireland.
authors.forename: James O
authors.initials: JO
authors.lastname: McInerney
authors.affiliation: Bioinformatics and Molecular Evolution Group, School of Biotechnology, Dublin City University, Glasnevin, Dublin 9, Ireland.
authors.forename: Mary J
authors.initials: MJ
authors.lastname: O'Connell
authors.affiliation: School of Biological Sciences and School of Earth Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, UK.
authors.forename: Davide
authors.initials: D
authors.lastname: Pisani
mesh_terms: D005075:Biological Evolution; D056890:Eukaryota / Q000235:genetics*; D011387:Prokaryotic Cells / Q000502:physiology*