Distinguishing a bunch of similar-looking plant and insect species from each other can be pretty hard. In fact, researchers claim that up to half of the world's natural history specimens (largely plants and insects) could be wrongly named.
In a study published on Monday in the journal Current Biology, researchers from Oxford University and the Royal Botanic Garden in Edinburgh describe how many plant specimens in the world's natural history museums might currently be masquerading under false identities.
They started off by evaluating 4,500 specimens of the African ginger genus Aframomum, on which a detailed monograph was conducted in 2014. A monograph is a complete revision of organisms (usually a family or genus), which involves sorting out all of the names associated with it. The researchers found that before this new monograph, up to 58 percent of the Aframomum specimens had outdated names, were misidentified, or only identified to the genus or family as opposed to the species level.
In 2004, researchers found a similar problem with insects. Zoe Goodwin, a co-author of the study and PhD researcher at Oxford University's Department of Plant Sciences, explained that as flowering plants and insects comprise two thirds of all named species, they estimate that around half of all specimens could have the wrong name.
"Our knowledge improves as different people look at the specimens," she said in a phone interview. "The big surprise was that, until the revision, most of the specimens [in the Aframomum group] didn't have the right name."
The main reason for the misidentification, said Goodwin, was down to the fact that little revision is conducted on the groups. "Nobody did what my supervisor did, which was bring in all the specimens and look at them together over several years," she said.
The researchers suggest that the same problem likely applies to other plant groups, given that monographs on them are few and far between.
"Sometimes specimens will acquire a different history as other people with different opinions put their names on it"
A shortage of human labor and a surplus of newly discovered specimens also adds to the problem.
"There was a huge increase in the number of specimens being collected in the 1970s. Even if you start working on a group, it's very difficult to keep naming specimens if you're suddenly receiving a lot of them," said Goodwin. "You need experts that can look at all the new material coming in and identify it."
And often, researchers divide and distribute samples from a single specimen to various museums around the world. While this allows other researchers to study a given specimen, it also increases the risk of that specimen receiving a different name from another botanist. "Sometimes specimens will acquire a different history as other people with different opinions put their names on it," explained Goodwin.
In their study, the researchers also give the example of the Dipterocarpaceae, a family of rainforest trees from Asia. They discovered that 9,222 specimens collected were divided into two or more samples, to make a total of 21,075 specimens. Twenty-nine percent of these possessed different names in different museum collections, highlighting the fact that at least one of the names must be wrong.
In order to tackle the proliferation of wrongly-named plants and insects in the world's natural history museums, Goodwin asserted the need for the taxonomic community to join forces. The researchers suggest that digitization projects and DNA barcoding—which enables them to identify specimens more quickly—could also aid the correct naming of species.
"The ideal vision of having a Star Trek-type of handheld device, telling you what plant you have from its 'barcode,' relies on us knowing the taxonomy, the names, and species of the group, and having all the databases up-to-date," said Goodwin.