Kim van der Linde
Common names of plants and animals often differ dramatically from country to country. In the past, this caused endless confusion and misunderstanding among scientists. To resolve this difficulty, 16th-century naturalists developed a standardised naming scheme that was later perfected by Carl Linnaeus. Under this scheme, each species has a two-part name. The first is the genus name, which is shared by several closely related species. The second is the species name.
To promote stability, there are rules governing the naming of species. Even so, names sometimes change, and species can be moved from one genus to another on the basis of new insights.
Most name changes go unnoticed by non-specialists and the general public. The imminent renaming of the fruit fly Drosophila melanogaster is an exception. This species is one of the most widely used in biology. It is often referred to simply as drosophila 鈥� a name that can be found in virtually every biology textbook and more than 50,000 scholarly articles.
Advertisement
The move to rename Drosophila melanogaster has arisen because the genus Drosophila as currently defined is a chaotic hodgepodge of species that are related to widely varying degrees. Cleaning up this royal mess to create a biologically consistent scheme will entail a name change: Drosophila melanogaster will have to become Sophophora melanogaster.
Though this problem has been recognised for decades, the implications of a name change have deterred any such move. No longer. Together with several colleagues I petitioned the to conserve the name. In March, after three years of deliberation, they rejected the request.
I think it is a bad decision. Changing a name as important as Drosophila melanogaster is asking for trouble.
For one thing, it flies in the face of name stability. What鈥檚 more, many researchers have an emotional bond with the old name and will refuse to use the new one. Several years ago the name of another laboratory workhorse, the mosquito Aedes aegypti, was changed to Stegomyia aegypti. Yet apart from mosquito taxonomists, everybody still uses the old name. The reassignment of a group of Hawaiian flies from Drosophila to the genus Idiomyia was similarly ignored.
鈥淢any researchers have an emotional attachment to the old name and will refuse to use the new one鈥�
Changing the name of Drosophila melanogaster will be met with even more resistance. Most likely drosophila will stick. There really is no point changing the name.
Amir Yassin
The great geneticist Theodosius Dobzhansky famously said: 鈥淣othing in biology makes sense except in the light of evolution.鈥� By this criterion, the genus Drosophila makes no sense. Most of its members belong to one of two subgenera, Sophophora and (confusingly) Drosophila, which are not actually very closely related. In fact, the subgenus Drosophila is more closely related to 20 other genera of small flies than it is to Sophophora.
Under normal circumstances this would not be a problem. We would simply reorganise the whole scheme to reflect biological reality, but that is easier said than done. Why? Because the famous laboratory fruit fly Drosophila melanogaster actually belongs in the subgenus Sophophora.
Taxonomically speaking, the most satisfactory solution is to split the genus Drosophila into several new genera. That would mean upgrading Sophophora from a subgenus to a genus 鈥� and hence changing the name Drosophila melanogaster to Sophophora melanogaster. This is not popular with geneticists.
The alternative is to lump all the groups together in a single genus, Drosophila. But while that would allow Drosophila melanogaster to keep its name, it would also result in a large number of taxonomic anomalies. For example, four species would all end up with the name Drosophila serrata. Four more would be called Drosophila carinata. This is a serious problem because species names reflect biological reality more than genus names.
What to do? I think we must favour the first solution.
There are very good taxonomic reasons for doing so. First, there is lots of evidence that Sophophora species are closely related, while the relationships between the other groups remain unclear. Secondly, only 332 species names will be affected, while the alternative will affect at least 1500 and possibly as many as 2000.
There is also no rational reason for geneticists to reject the change. They already use drosophila as a colloquial name for all the species in the family Drosophilidae 鈥� nearly 70 genera. Nothing need stop them continuing to call Sophophora melanogaster plain old drosophila. As for emotional attachment, that didn鈥檛 prevent astronomers from downgrading Pluto鈥檚 status as a planet.
鈥淓motional attachment did not stop astronomers from downgrading Pluto鈥檚 status as a planet鈥�
The subgenus Sophophora was created in 1939 by Alfred Sturtevant, one of the founding fathers of drosophila genetics. His overriding purpose was to create a 鈥渟cheme of classification indicating degree of genetic relationship鈥�. It is clear that the existing scheme no longer serves that purpose. Renaming Drosophila melanogaster is the right thing to do.
