Research Article |
Corresponding author: Thomas Pape ( tpape@snm.ku.dk ) Academic editor: Ellinor Michel
© 2016 Christian Thompson, Thomas Pape.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Thompson CF, Pape T (2016) Sherborn’s influence on Systema Dipterorum. In: Michel E (Ed.) Anchoring Biodiversity Information: From Sherborn to the 21st century and beyond. ZooKeys 550: 135–152. https://doi.org/10.3897/zookeys.550.9447
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Flies make up more than 10% of the planetary biota and our well-being depends on how we manage our coexistence with flies. Storing and accessing relevant knowledge about flies is intimately connected with using correct names, and Systema Dipterorum provides a single authoritative classification for flies developed by consensus among contributors. The 160,000 species of flies currently known are distributed among 160 recent families and some 12,000 genera, which with their synonyms encompass a total of more than a quarter of a million names. These names and their associated classification are shared with relevant global solutions. Sherborn appears to have done remarkably well indexing Diptera names with an overall error rate estimated to be close to 1%.
Flies, nomenclator, taxonomic catalog, identification, biodiversity informatics infrastructure, quality assurance standard
Flies are ubiquitous and dominant in most terrestrial ecosystems, by their numbers of species as well as by their immeasurable myriads of individuals. Flies come in a multitude of forms and with an exceedingly vast array of life habits and are often considered the ecologically most varied of the insect orders. Fly larvae in particular are ecologically versatile and have adapted to the harshest of habitats, from pools of crude oil and torrential mountain streams to the bacterial soups of pit-latrines and vertebrate carrion. Flies flourish in the highly disturbed environments created by human activities, often reaching nuisance levels, and flies not surprisingly interfere with man in numerous and varied ways. On the dark side, flies dominate among the blood-sucking pests, with some of the most potent of human diseases being transmitted by dipterous vectors, thereby causing suffering that goes beyond description. However, flies are also beneficial, for example through their processing and recycling of the large quantities of surplus organic material produced by many of our modern societies (
The significance of flies reaches deep into our culture. Disease-carrying flies have had tremendous impact on local demography and land-use far beyond any other group of insects, and in the case of West African sickle-cell anemia, flies—even if mediated through a parasite—have reached into our very genome by indirectly favoring a specific genetic mutation (
Flies are ancient. The earliest flies began diversifying in the Upper Triassic some 225 million years ago (
What do people want to know about flies? People may be confronted with a fly that is strange to them, so they may want to know: “What is it?”, “What does it do?” and “Where did it come from?” Or they may have a specific problem, for example with rotting oranges, and when learning that a fly maggot is the problem, they may want to know what fly it is. The resolution in each case starts with the identification of the fly, i.e., the first and crucial step leads to a name. With the right name, people get access to knowledge (
Knowledge about life (organisms over time), which was first essentially locked up in Systema Naturae, is now dispersed across hundreds of thousands of works, but maybe some day soon it will again be unified—or rather interconnected by means of an Encyclopedia of Life (http://www.eol.org). To build such an all-encompassing encyclopedia, we must first assemble the critical pieces of the biodiversity informatics infrastructure. Just as what we need for life in a modern society is transported on a system of airways, highways, seaways, and railways, biodiversity information must also be disseminated via a critical infrastructure. That infrastructure starts with nomenclators and catalogs, and the information is mediated by way of names. Information on identification and classification is disseminated through revisions and monographs. Most of the infrastructure of systematics remains in the traditional printed medium, but the migration to the online, digital medium of the Internet has begun. For flies, the first critical component of the biodiversity informatics infrastructure is the
The past is our prologue as we build on the knowledge of our predecessors and learn from their mistakes. The official start of the modern understanding of flies and their classification has been deemed to be the 10th edition of Linnaeus’ Systema Naturae in 1758 (
Number of valid genera and valid species as well as total number of names for the three major Diptera nomenclators through time (fossils excluded).
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Systema Dipterorum 2013 | |
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Genera | 10 | 78 | 12,073 |
Species | 191 | 1,151 | 160,042 |
Names | 201 | 1,242 | 272,029 |
Authors | 24 | 46 | 5,701 |
Comprehensive works like the Systemae of Linnaeus and Fabricius fell victim to the rapid increase in biodiversity information. We do understand what we have lost, and using modern technologies (computers and the Internet), we have begun to build their modern equivalents (e.g., Encyclopedia of Life, Species2000, ZooBank; see also
What information sources are currently available to help us build the new online Systema Dipterorum? As knowledge expanded and became larger than what one person could assimilate, as happened to Linnaeus and Fabricius, the universe of knowledge was subdivided into smaller, more manageable shares. This division was based on different approaches, some divided up the universe by the taxon, others by time or geography or people.
Division by taxon is simple: once Linnaeus (and then Gmelin) did all organisms, then Fabricius did all arthropods and finally all flies, but after that the division of labor was by geography, with Meigen doing all the flies of Europe and Wiedemann doing all the “exotic” (i.e., non-European) flies. Later, the amount of information became too large for comprehensive works, so a new format (catalogs) were invented and used as a summary of our knowledge, having merely a citation to the basic information. The first catalog for Diptera was produced by
Another division of knowledge was by the publications—works that included knowledge about organisms. One of the first to attempt making a bibliography of all works related to zoology (and geology) was
Just as bibliographies greatly facilitate our access to published works, a main portal to scientific names is embodied by the indexes built for those names. The monographs by Linnaeus and Fabricius were such indexes in addition to being taxonomic tools. After them, however, few comprehensive indexes were developed, and although high-profile initiatives are now underway to dynamically interconnect existing indexes in a way that streamlines the taxonomic enterprise (
Today, how do we assess Sherborn’s accomplishments? First, we need to appreciate the platform of nomenclatural legislation that Sherborn worked from. Today we have the 4th edition of the International Code of Zoological Nomenclature, but Sherborn worked under the ‘Strickland Code’ (
Letter from Sherborn to Griffin accompanying one of his “Want” lists. The text of the message says: “Dear Griffin Thanks for pamphlets herewith recd. Enclosed list of my wants in Entom. etc. I don’t suppose you will get all etc but I’ll be glad to buy any of them you come across. Yours C. Davies Sherborn”.
How good was Sherborn? For a study of the species-group names proposed in the genus Musca, Sherborn indexed 1,807 names.
The impediments that made the continued updating of Linneaus’ original Systema impossible were the inflexibility of printing and the increased cost of disseminating knowledge by printing with fixed types and reproducing text in ink on paper. Today, computers are taking over the physical aspects of printing and provide an easy means for integrating the past with current knowledge, and they also allow for alternative dissemination media beyond paper. The Internet with the World Wide Web is a relatively new and ever more dominating medium, allowing anyone anywhere with a computer and online access to receive information in real time from anywhere in the world. The modern workflow in monographic taxonomy is at least potentially greatly enhanced (
A Chinese proverb ascribed to Confucius states that wisdom begins with applying the correct names (“If names be not correct, language is not in accordance with the truth of things”; cf. Legge 1971).
Our survival and well-being ultimately depends on accumulated knowledge about the ‘nuts and bolts’ of the natural world, and perhaps nowhere else in the natural sciences do we find a greater variety of different ‘units’ than in the biological discipline of taxonomy. Ever since Linnaeus, the basic unit of biological classifications is the species, and with our living world containing an estimated 5–12 million species, the need for names obviously is paramount.
Classifications are merely hierarchical groupings, and in evolutionary biology the basic unit is the species.
The last but most important set of components of the biodiversity infrastructure for users is identification tools. These range from the early paper-based diagnoses provided by Linnaeus and Fabricius to modern interactive, image-rich expert systems that run on hand-held tablets and smartphones, which from being available only for more conspicuous species like birds and whales, now are rapidly expanding to include applets for categories like forest pest insects, tree fungi, mushrooms and broadleaf weeds. For the flies, there are still only a few examples of identification tools that have left paper as the medium for storing and conveying relevant information. Primary examples of CD-ROM based identification systems for flies are the Fruit Fly Expert Identification System (
The SD is designed as a comprehensive online information source for all the critical information about scientific names of flies and the basic information about species of flies. This system grew out of a vision of a group of dipterists who wanted to capitalize on the knowledge that had been generated in preparing a series of regional catalogs of Diptera, which began in the 1960s with a catalog of Nearctic (or rather North American) Diptera that involved Canadian and U.S. fly specialists (
The SD is today a fully online system containing all the critical information about the system itself and its contents. What follows here is merely a snapshot of what was available online as of October 2013. Irregularly, the SD (initially as the BioSystematic Database of World Diptera) is archived to CD-ROM via the Diptera Data Dissemination Disk series (
The nomenclator and reference files contain all the essential nomenclatural details as well as minimal species information. For each name, information is provided about the original source and format of the name, correct spelling and type information if the name is available, the nomenclatural and taxonomic status of the name, the distribution, and a link to the original reference. The predecessor of Systema Dipterorum, the
The SD continues to be built incrementally so as to provide useful information more quickly than having to wait until it is complete at optimal standards (the sources from which the SD was built are documented online). Each record includes a quality assurance standard indicator (these are also documented online) telling users how complete the record is especially in respect to our ultimate status of taxonomic and nomenclatural peer review by assigned specialists. Records meeting the ultimate level are identified by the name(s) of the specialist(s) and date of review. Currently only about 6% of records meet this highest level, but in reality most records are as good as those already published (that is, the source from which they derived) or better (Table
Systema Dipterorum statistics as of October 2013 indicating number of records and the proportion reaching the quality assurance level at which they are ready for pre-publication peer review.
Number of records: |
198,258 species-group names (160,042 valid) |
23,437 genus-group names (12,073 valid) |
32,900 references |
Records compared to original literature: |
29,493 species (~15%) |
6,138 genera (~27%) |
Records nomenclaturally and taxonomically reviewed: |
11,509 species-group names (~6%) |
2,462 genus-group names (~11%) |
With ZooBank (
The planned species interface will differ from the nomenclator only in the way the user can query the information. At present, a user enters a name and the nomenclator returns nomenclatural and taxonomic information about that name. The species interface will allow queries about the species and some of its other attributes, such as distribution and biology. So, one can ask, for example, for a list of all the fruit flies known from Costa Rica or for a list of all the species that are known to attack a certain fruit. The challenge of the species interface will be to determine which attributes users want to query (e.g., Conservation status? Distribution? Economic importance? Hosts? Morphology?) and then encode that information. Today, the nomenclator includes only minimal distributional data for species.
The most important aspect of the whole SD enterprise is our team—the people who have contributed their expertise and labor to build the SD (and before that the BDWD).
The final aspect of the SD is its legal status, which is documented online under ‘How to cite & copyrights’. The critical fact is that SD is a community enterprise built by dipterists for themselves and for all people. So the information is without copyright and is freely available to all. While at various times the master database may have resided physically in some institution, that master was always a product of the SD team and belonged to those people. When the SD first went online, it was hosted by the Smithsonian Institution; later it was transferred to the USDA, and most recently it is served by the Natural History Museum of Denmark. In the future it will keep migrating to the best place that is willing to properly maintain and improve it.
We express our thanks to the entire Systema Dipterorum team of contributors and to all others who have supplied information over the years, and to the Schlinger Foundation, the Global Biodiversity Information Facility, the United States Department of Agriculture, and our home institutions, all of which provided financial support at various times. Neal Evenhuis, Dan Bickel and Steve Gaimari skillfully commented on the manuscript.