How big is a genus? Towards a nomothetic systematics

    Research output: Contribution to journalArticle

    Published

    View graph of relations

    A genus is a taxonomic unit that may contain one species (monotypic) or thousands. Yet counts of genera or families are used to quantify diversity where species-level data are not available. High frequencies of monotypic genera (~30% of animals) have previously been scrutinised as an artefact of human classification. To test whether Linnean taxonomy conflicts with phylogeny, we compared idealised phylogenetic systematics in silico with real-world data. We generated highly-replicated, simulated phylogenies under a variety of fixed speciation/extinction rates, imposed three independent taxonomic sorting algorithms on these clades (2.65x10^8 simulated species), and compared the resulting genus size data with quality-controlled taxonomy of animal groups (2.8x10^5 species). ‘Perfect’ phylogenetic systematics arrives at similar distributions to real-world taxonomy, regardless of the taxonomic algorithm. Rapid radiations occasionally produce a large genus when speciation rates are favourable; however, small genera can arise in many different ways, from individual lineage persistence and/or extinctions creating subdivisions within a clade. The consistency of this skew distribution in simulation and real-world data indicates that specific aspects of its mathematical behaviour could be developed into generalised or nomothetic principles of the global frequency distributions of higher taxa. Importantly, Linnean taxonomy is a better-than-expected reflection of underlying evolutionary patterns.

    Documents

    • How big is a genus? Towards a nomothetic systematics

      Rights statement: ​Copyright 2017 Oxford University Press This work is made available online in accordance with the publisher’s policies. Please refer to any applicable terms of use of the publisher.

      Accepted author manuscript, 923 KB, PDF-document

    DOI

    Original languageEnglish
    JournalZoological Journal of the Linnean Society
    Journal publication date13 Oct 2017
    DOIs
    Publication statusPublished - 13 Oct 2017

    ID: 136525939