Keys and the Crisis in Taxonomy: Extinction or Reinvention?

Abstract

Dichotomous keys that follow a single pathway of character state choices to an end point have been the primary tools for the identification of unknown organisms for more than two centuries. However, a revolution in computer diagnostics is now under way that may result in the replacement of traditional keys by matrix-based computer interactive keys that have many paths to a correct identification and make extensive use of hypertext to link to images, glossaries, and other support material. Progress is also being made on replacing keys entirely by optical matching of specimens to digital databases and DNA sequences. These new tools may go some way toward alleviating the taxonomic impediment to biodiversity studies and other ecological and evolutionary research, especially with better coordination between those who produce keys and those who use them and by integrating interactive keys into larger biological Web sites.

Data publication and dissemination of interactive keys under the open access model

“…Dallwitz 2000;Dallwitz et al 2000;Farr 2006;Walter and Winterton 2007). Rather, we discuss and off er a model for open data publishing that allows a wider dissemination and reuse of data and interactive keys, and proper publication credit.…”

“…In his Systema, the attributes were directly embedded in his hierarchical classifi cation. Lamarck, in 1788, was the fi rst to separate the identifi cation process from the classifi cation by making keys: hierarchical sets of choices between character states (Walter and Winterton 2007). Th ese are usually called "dichotomous keys" (although strictly speaking this term should be restricted to keys having only two choices at each branching point), and sometimes "conventional keys", "single-access keys", or "pathway keys".…”

Electronic polytomous and dichotomous keys to the genera and species of hard ticks (Acari: Ixodidae) present in New Zealand

“…The worldwide decline in taxonomic expertise (Godfray 2002, Walter & Winterton 2007, Wheeler 2004) is inhibiting prevention and management of biological invasions (Lodge et al 2006). Protocols for diagnosing pests and diseases underpin essentially all quarantine activities, and lowquality, inaccessible or absent taxonomic keys are major impediments to effective border biosecurity and pest management (IPPC 2006, Lodge et al 2006.…”

“…Protocols for diagnosing pests and diseases underpin essentially all quarantine activities, and lowquality, inaccessible or absent taxonomic keys are major impediments to effective border biosecurity and pest management (IPPC 2006, Lodge et al 2006. For a taxonomic specialist, identifying a specimen may only require a brief check of critical characters (Walter & Winterton 2007). However, less specialised diagnosticians dealing with unfamiliar species in quarantine situations require extremely well-designed taxonomic tools to obtain correct identifications.…”

Character Selection During Interactive Taxonomic Identification: “Best Characters”

“…Many of the identification keys that are being made available online also either use binary characters only (Toda et al 2004;Guala 2004-12;Christensen 1999;Rosatti undated) and/or are automated versions of traditional keys (Martellos 2010) called "pathway keys" by Walter and Winterton (2006). Software is available, however, for implementing general polyclaves that allow multi-state characters and an unconstrained sequence of character selection (Dallwitz 1993;Brach and Song 2005;Alexander 2006;Lucidecentral.org 2010;Ung et al 2010).…”