title: How natural a kind is "eukaryote?".
abstract: Systematics balances uneasily between realism and nominalism, uncommitted as to whether biological taxa are discoveries or inventions. If the former, they might be taken as natural kinds. I briefly review some philosophers' concepts of natural kinds and then argue that several of these apply well enough to "eukaryote." Although there are some sticky issues around genomic chimerism and when eukaryotes first appeared, if we allow for degrees in the naturalness of kinds, existing eukaryotes rank highly, higher than prokaryotes. Most biologists feel this intuitively: All I attempt to do here is provide some conceptual justification.
authors.affiliation: Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
authors.forename: W Ford
authors.initials: WF
authors.lastname: Doolittle
mesh_terms: D005057:Eukaryotic Cells; D013045:Species Specificity