Classifying Flora and Fauna

This is likely by far the hardest class to classify. The number of different organisms is simply enormous, and the process of placing each within a logical hierarchy is still a work in progress. But there is an advantage here in developing a new system of classification for we are learning more each day about the proper classification of organisms, and their constituent components. While biologists still debate which species are most closely related to which others, the boundaries of species are subject to much less debate. Unlike with personality dimensions, there is considerable consensus regarding the broadest groupings.

NOTE: We have in 2021 changed our F schedule to reflect advances in cladistics: the classification of species based on genetic similarity. This replaced an Old F Classification that employed longstanding terminology such as Kingdoms, Orders, and Families. With genetic analysis, some "trees" of heredity are much longer than others.

There is a movement within the biodiversity informatics community to provide unique numeric identifiers for all biological names. This would allow authors to cite names unambiguously in electronic media and reduce the significance of errors in the spelling of names or the abbreviation of authority names. Three large nomenclatural databases (referred to as nomenclators) have already begun this process.

Not everyone is satisfied with this approach. But it raises the possibility that it might be best to use these indicators in future.

The field of biology is moving steadily toward cladistic analysis in which species are organized strictly in terms of evolutionary descent. At present species are still often organized hierarchically in terms of similarities in physiology. It will be advantageous if possible to begin with a cladistic hierarchy and fill in the details as biological analysis proceeds.

Blake (in Knowledge Organization 38:6) discusses several problems in classifying zoology. First, he suggests that the needs of library classification diverge from those of scientific classification due to literary warrant. In particular, zoologists increasingly wish to classify in terms of clades: sets of all descendants of an ancestral species. But authors often want to speak of non-cladistic groups such as fish, reptiles, and non-human apes. The BCC may be better able to address these related problems by classifying species cladistically, but allowing linked notation to describe these other groups. A more troubling challenge is that scientists are frequently adjusting their cladistic classifications in the light of new genetic analyses. This means that the BCC can benefit from the latest understanding (whereas extant classifications have many groupings now thought to be inappropriate; UDC is in the process of updating its schedules). But it is likely that many changes will occur in the next years (though we may be near consensus on mammals). Delay in developing a hierarchical classification here may thus be warranted. There are many (certainly more than the seven common ranks) levels of clades, and clades at the same level are of quite different sizes -- classifying in terms of clades thus presents notational challenges. Scientific names can be ambiguous and are changed; different classifications give different names to the same animal: DDC thus increasingly provides both vernacular and scientific names and warns of ambiguity. BCC could follow a similar approach.

Note: It is expected that anatomy can generally be dealt with by linking organisms to classifications of tissues, organs, and biological systems. Some general indicator of the concept "anatomy" itself will also be required.

We will also need somewhere to classify developmental forms, starting from eggs, spores, and so on, through foetuses and such.