Wednesday, November 18, 2015

Comments on "Widespread mistaken identity in tropical plant collections"

Zoë A. Goodwin (@Drypetes) and collegagues have published a paper with a title guaranteed to get noticed:

Goodwin, Z. A., Harris, D. J., Filer, D., Wood, J. R. I., & Scotland, R. W. (2015, November). Widespread mistaken identity in tropical plant collections. Current Biology. Elsevier BV.

Their paper argues that "more than half of all tropical plant collections may be wrongly named." This is clearly a worrying conclusion with major implications for aggregators such as GBIF that get the bulk of their data (excluding birds) from museums and herbaria.

I'm quite prepared to accept that there are going to be considerable problems with herbarium and museum labels, but there are aspects of this study that are deeply frustrating.

Where's the data?

The authors don't provide any data! This difficult to understand, especially as they downloaded data from GBIF which provides DOIs for each and every download. Why don't the authors cite those DOIs (which would enable others to grab the same data, and also ultimately provides a way to provide credit to the original data providers)? The authors obtained data from multiple herbaria, matched specimens that were the same, and compared their taxonomic names. This is a potentially very useful data set, but the authors don't provide it. Anybody wanting to explore the problem immediately hits a brick wall.

Unpublished taxonomy

The first group of plants the authors looked at is Aframomum, and they often refer to a recent monograph of this genus which is cited as "Harris, D.J., and Wortley, A.H. (In Press). Monograph of Aframomum (Zingiberaceae). Syst. Bot. Monogr.". As far as I can tell, this hasn't been published. This not only makes it hard for the reader to investigate further, it means the authors mention a name in the paper that doesn't seem to be have been published:
In 2014 the plant was recognized as a new species, Aframomum lutarium D.J.Harris & Wortley, by Harris & Wortley as part of the revision of the genus Aframomum
I confess ignorance of the Botanical Code of Nomenclature, but in zoology this is a no no.

What specimen is show in Fig. 1?

Gr1 lrg Figure 1 shows a herbarium specimen, but there's no identifier or link for the specimen. Is this specimen available online? Can I see it in GBIF? Can I see it's history and explore further? if not, why not? If it's not available online, why not pick one that is?

What is "wrong"?

The authors state:
Examination of the 560 Ipomoea names associated with 49,500 specimens in GBIF (Figure S1A) revealed a large proportion of the names to be nomenclatural and taxonomic synonyms (40%), invalid, erroneous or unrecognised names (16%, ‘invalid’ in Figure S1A). In addition, 11% of the specimens in GBIF were unidentified to species.
Are synonyms wrong? If it's a nomenclatural synonym, then it's effectively the same name. If it's a taxonomic synonym, then is that "wrong"? Identifications occur at a given time, and our notion of what constitutes a taxon can change over time. It's one thing to say a specimen has been assigned to a taxon which we now regard as a synonym of another, quite another to say that a specimen has been wrongly identified. What are "invalid, erroneous or unrecognised names"? Are these typos, or genuinely erroneous names? Once again, if the authors provided the data we could investigate. But they haven't, so we can't examine whether their definition of "wrong" is reasonable.

I'm all for people flagging problems (after all, I've made something of career of it), but surely one reason for flagging problems is so that they can be recognised and fixed. By basing their results on an unpublished monograph, and by not providing any data in support of their conclusions, the authors prevent those of us interested in fixing problems being able to drill down and understand the nature of the problem. If the authors had both published the article and provided the data they would have done the community a real service. Instead we are left with a study with a click bait title that will get lots of attention, but which doesn't provide any way for people to make progress on the problem the paper identifies.