A re‐analysis of the data in Sharkey et al.’s (2021) minimalist revision reveals that BINs do not deserve names, but BOLD Systems needs a stronger commitment to open science

Abstract

Halting biodiversity decline is one of the most critical challenges for humanity, but monitoring biodiversity is hampered by taxonomic impediments. One impediment is the large number of undescribed species (here called "dark taxon impediment") whereas another is caused by the large number of superficial species descriptions, that can only be resolved by consulting type specimens ("superficial description impediment"). Recently, Sharkey et al. (2021) proposed to address the dark taxon impediment for Costa Rican braconid wasps by describing 403 species based on COI barcode clusters ("BINs") computed by BOLD Systems. More than 99% of the BINs (387 of 390) were converted into species by assigning binominal names (e.g. BIN "BOLD: ACM9419" becomes Bracon federicomatarritai) and adding a minimal diagnosis (consisting only of a consensus barcode for most species). We here show that many of Sharkey et al.'s species are unstable when the underlying data are analyzed using different species delimitation algorithms. Add the insufficiently informative diagnoses, and many of these species will become the next "superficial description impediment" for braconid taxonomy because they will have to be tested and redescribed after obtaining sufficient evidence for confidently delimiting species. We furthermore show that Sharkey et al.'s approach of using consensus barcodes as diagnoses is not functional because it cannot be applied consistently. Lastly, we reiterate that COI alone is not suitable for delimiting and describing species, and voice concerns over Sharkey et al.'s uncritical use of BINs because they are calculated by a proprietary algorithm (RESL) that uses a mixture of public and private data. We urge authors, reviewers and editors to maintain high standards in taxonomy by only publishing new species that are rigorously delimited with openaccess tools and supported by publicly available evidence.

Diagnosing diagnoses – can we improve our taxonomy?

“…For some, this is a panacea to deal with the often-overwhelming diversity present in some tropical habitats and/or hyperdiverse genera noted for small or miniscule morphological differences. There are, however, serious challenges that indicate the questionable interpretation of such results ( Ahrens et al 2021 ; Meier et al 2021 ). What remains, however, is that there are currently some groups of species which are so morphologically similar that it is not possible to either key them and, by extension, provide a diagnosis.…”

Braconidae (Hymenoptera) parasitoid wasps as a model group for turbo taxonomy approaches: lessons from the past and recommendations for the future

“…I strongly recommend the reading of papers such as Pinheiro et al (2019), Dupérré (2020), Zamani et al (2020), Ahrens et al (2021), Engel et al (2021, Meier et al (2021), Srivathsan et al (2021) and references cited there (other papers provide slightly different alternatives or approaches, and are also recommended reading, e.g., Brower (2010), Blaxter (2016), Goulding & Dayrat (2016), Renner (2016), Brown & Wong (2020), Vences (2020); this list is not exhaustive). And to present a more complete and fairer picture, the reader should also consider a second paper by Sharkey et al (2021b) which tried to provide counterarguments to some of the received criticism (although that paper has also been met with additional counterarguments on its own, e.g., Ahrens et al (2021), Engel et al (2021 and Meier et al (2021)).…”

“…It all looks so nice and promising! While I have no doubts that technology ultimately will be developed to allow fast, easy and cheap devices to obtain and analyse DNA, and access the comprehensive DNA databases that are necessary to determine whether a specimen at hand represents a described species, that scenario is not yet here (but see Srivathsan et al 2021 for some new developments that could become viable alternatives in the near future). We are still far from being able to download a "Taxonomy for Dummies" app.…”

“…In the months following that paper, the scientific community has engaged in lively discussions about "how useful" such descriptions are, whether they in fact impede the cataloguing of biodiversity, "how valid" (from the ICZN perspective) those species are, and general issues about the future of taxonomy, shortcomings of BINs and even BOLD (e.g., Ahrens et al 2021, Engel et al 2021, Meier et al 2021.…”

Riding into the future on a fly: toward a better understanding of phoresy and avian lice evolution (Phthiraptera) by screening bird carcasses for phoretic lice on hippoboscid flies (Diptera)

“…Note, however, that such assignments of specimens to putative species via barcodes is no endorsement for describing species based on barcodes only. As argued by numerous authors (Ahrens et al, 2021;Engel et al, 2021;Meier et al, 2021), barcode clusters are first-pass grouping statements that require additional testing before they can be properly described as species. Instead, pre-sorting specimens to putative species using barcodes is the first step toward taxonomic revision.…”