A guest blog by my colleague Priya Rangan on the acacia name issue. Taxonomists be warned, you’ll either laugh or cry at this engaged, humorous, but deadly serious satire of the history of botanical nomenclature, the science of taxonomy, and the current wattle wars. The solutions Priya proposes are important and novel.
Priya writes: ”The views, discussions, and comments regarding the Acacia name are fascinating. I am glad to see that finally the cards are on the table: the name change issue has little to do with so-called scientific objectivity and rules of nomenclature, and everything to do with the feelings and tastes of concerned taxonomists. Although I’m mangling the quote here, “Oh, what a tangled web we weave,” when we use science to deceptively conceal our personal likes and dislikes.
I must confess that I am not a taxonomist in any way, but my work involves looking at Acacia species (African, Indian, Australian, and Central American) in their social contexts. So I am, if you like, an ‘interested participant-observer’ or ‘stakeholder’ in this debate. Here’s how I see this story:
A bunch of taxonomists who have embraced molecular genetic analysis feel they need to reorder plant genuses (or are they genii? that would be an appropriate homonym, wouldn’t it!) according to something called monophyly. They look at the broad genus Acacia and say, “Horrors, we can’t have such a polyphyletic mess! We need to order this so that it shows current progress in our fine science!” So they decide to split this genus into three, and figure out they’ve got to come up with names for each. Some of them get very enthusiastic and, following the venerable codes established by their community, strictly obey the ‘rule of priority’ by leaving the genus name Acacia for those plants that have been typified as such for a very long time. Then they look, as they were told by their ancient code, for the earliest evidence of an alternative name used to describe a species of the Australian branch of acacias, and find the name Racosperma. Racosperma it is, they say, and can’t wait to start renaming all the Aussie species.
So far, all this makes sense (that is, if you are the sort of taxonomist that believes the genus needed to be split; there are plenty of other taxonomists who think this is quite unnecessary, but we won’t talk about them at this point). They’re hip and happening cladists, they think splitting genuses is the best thing since sliced bread, they’ve followed all the rules, and to prove it all, they’ve gone an published a long list of the new combinations… Racosperma penninervis, Racosperma dealbata and so on.
It also makes sense that they reserved the genus name Acacia for the trees that were given this name at least three hundred years ago, and if you want to be picky, going as far back as about 2300 years. A Greek natural philosopher called Theophrastus named these trees that he saw in Egypt as Acacia. The root word for the name is ‘akis’, which means thorn; the trees were named acacia because they were best distinguished by their thorns. This tree, now known by its Latin name Acacia nilotica, has been the ‘type’ species for Acacia well before and ever since Carl Linnaeus came up with his taxonomic system that was enthusiastically embraced by European naturalists (actually, if you take a look at Linnaeus’ descriptions, he refers to the genus as both Mimosa and Acacia; this chap called Miller later decided to reduce the confusion caused by Linnaeus’ double use by making the family name Mimosa (covering whole lot of leguminous tree species including acacias) and the genus name Acacia). Based on this rather straightforward logic, Linnaeus and others following him described other trees that had similar morphology in their leaves, thorns, and flowers as various kinds of acacias. So the thorny, bipinnate-leaved tree that had been brought from Central America to Europe during the 16th or 17th century and described according to the specimen found in Cardinal Farnese’s gardens in Rome was called Acacia farnesiana. And, you mustn’t forget, all these names were around well before Captain Cook and his shipmates ‘discovered’ Australia in 1770, and well before any European naturalist described the plant species from that continent using Linnaeus’ system.
You get the picture… any thorny bi-pinnate leaved tree with puffy-balled flowers you see and don’t recognise, you say, “I can safely start by classifying it as belonging to the genus Acacia and give the unique species name as thingummy, Acacia thingummy. But then someone else might come along and say, “Look mate, you got it wrong. There’s someone else who described this plant earlier and they called it Mimosa abracadabra, so we can’t have you calling it Acacia thingummy, if you see what I mean.” And you’d probably reply (if you were the civilised sort without a huge ego), “Thanks for letting me know, old chum”, and get on with calling it Mimosa abracadabra. The first chap who called a whole bunch of Australian plants ‘acacia’ probably did something similar…. Looked at them and thought, “Well, they look like acacias, with their bipinnate leaves and puffy-ball flowers, and they have seed pods… they don’t have thorns though, but I think I might as well save myself the bother and place them under the genus Acacia”. He probably thought that if any ordinary person came across these trees, they would end up calling them Acacia using the same sorts of judgements and comparisons, so why complicate matters and come up with a new genus name? Little did he know what was lurking in the horizon…. Racosperma (ominous drumroll please)
So, getting back to the genus-splitting consequences… The Australian botanists who fervently believe in the cause of splitting genus are confronted by the sobering prospect of calling a whole bunch of the Australian species by the genus name Racosperma. They probably rehearsed saying it in their heads: Racosperma, rrracosperma, racosperma; whichever way they say it, it doesn’t sound good… Infact, it sounds pretty rough, even bordering on lewd (though lewd should have been fine, very macho … Linnaeus had no problems using sexual allusions for classifying plants), specially if you roll the ‘r’ or emphasise the sperma bit of the name. They look to the future and see themselves being introduced at conferences and lectures as rrracosperma specialists, Racosperma researchers instead of Acacia researchers. The thought is jarring, the vision simply unbearable. Something has to be done, and done soon to avoid this dreadful fate. They want to keep the nice-sounding name acacia for their species and to hell with everyone else!
Oh Acacia, acacia! “Was this the euphonic name that launched a battle and burnt the topless towers of Taxonomy (apologies to Christopher Marlowe)?” Alas, it was. The Australian botanists scoured the rule book of nomenclature and found one they could use as their weapon to keep the name for their species. To use this weapon, they would have to provide a lot of justification in ‘rational’ terms: economic costs of changing the name, the number of people, industries or sectors affected by the name change, and any other ‘rational’ (mainly economic) criteria that they could muster for keeping the name exclusively for their species. If you made this case successfully, then you could argue that the ‘rule of priority’ could be set aside, and that the genus name Acacia could be linked to another ‘type’ species; that’s to say you could replace the old ‘type’ species, Acacia nilotica, with a new type, Acacia penninervis, an Australian species.
And so they did, building their case, mustering up all sorts of numbers and reasons before the 2005 Botanic Congress took place in Vienna. The Vienna Conference arrived, and the stage was set for the nomenclature battle. The Australian botanists probably knew this daring hijack wasn’t going to be easily pulled off, but they were prepared, leaving nothing to chance. Alliances had been built with sympathisers in powerful places, officials in the high echelons of Taxonomy carefully seduced by a dazzle of quantifications and figures. The committee decided that the numbers and figures presented by the Australian botanists were good enough to support the case for retypification. They passed along the decision to the whole Congress on the last day, and asked the attending members to vote. The vote for retypification took place on the last day of the Congress. Roughly 55% of the voters rejected the proposal, but it was passed anyway.
“How on earth could that happen?” you might well ask! What sorts of rules did they follow? Did everyone understand what was going on?
Well, of course there were rules! Can you imagine a Scientific Nomenclature Committee without rules? And of course, you’d think, everyone knew the rules and understood what was going on; they were scientists, after all, and members of that unique species, Homo taxonomicus. Turns out it was more complicated. I don’t know if quite I get it (I’m not a taxonomist, so that might be my great failing) but apparently the rule was that you needed a 60% majority vote to overturn the recommendation for retypification. Since only 54.9% of the voters at the Congress opposed the recommendation, the decision to retypify was passed.
The scientists opposing retypification were predictably indignant. There wasn’t a clear majority vote ‘for’ the decision to retypify, and more than half of the voters were ‘against’ it. There would have been plenty more members from poorer countries affected by the name change that would have voted against the recommendation if they’d had the money to attend the conference. If they’d known, they would have gathered their proxy votes and submitted them at the conference. From their point of view, the rule of priority should have held, the committee’s decision was based on flawed reasoning, and the voting process was questionable to say the least. The Australian botanists proposing the retypification probably couldn’t have cared less about all the reasoning and procedural stuff. All that mattered was that they’d pulled off the most daring hijacking ever attempted in the world of Taxonomy, and their species wouldn’t have to suffer under the genus name Racosperma!
The story, of course, didn’t end there. The opposing scientists didn’t just retire into the shade to lick their wounds and mope over the loss. They weren’t just angry, they were mad as anything, and were going to get even. Over the past 6 years, they’ve ratcheted up the volume of criticism against the decision and it’s beginning to have a lowering effect on the smugness levels of the Australian botanists. They realise that the opposition are going to come well armed to fight this battle at the 2011 Botanical Congress in July. Even though it is on home turf, the opposition won’t be caught out again, and is likely to muster a large number of proxy votes to overturn the Vienna decision.
The reaction of the defenders of the Vienna decision is predictable. The best form of defence in such situations is to accuse the opposing party of being ‘unscientific’ or implying that they lack the ability to understand the rules (perhaps hinting that although they are part of their species Homo taxonomicus, they aren’t evolved enough to comprehend such complexities?), which is what some Australian botanists and Committee officials appear to be doing. Australian botanists are urging all their members, including any interested member of the public to shell out some hefty registration fees and exercise their vote to keep the Vienna decision. Others have come up with ‘compromise’ proposals that look about as attractive as lukewarm gruel in a faux silver dish.
So, you might ask, what kind of ending would I like to see for this story? I have two endings in my mind.
My first preference is to tell the warring tribes to pull their heads in and, for a change, listen to others of their kind who see no reason to subdivide genuses to the point that there is no way of recognising or understanding variability among species. So what if Acacia is polyphyletic? Why not just say so, and then say that’s what makes it really interesting to study. I like the fact that the broad genus Acacia allows you to see the diversity of species, makes you wonder how and why this diversity came about, think about geographic and climatic factors influencing evolutionary processes… I like the fact that acacias are to be found just about everywhere in the world and that they make us think about commonality and differences just as we do with ourselves and our societies. My preference, therefore, is to propose a new vote to keep the broad definition of Acacia. I don’t know what procedure that involves, or whether this would be tantamount to Blasphemy for practitioners of High Taxonomy. All I know is that whatever happens, I certainly will not use the genus name Vachellia for the trees I study, Acacia nilotica and Acacia farnesiana. If the Australian botanists have the same feeling towards using the genus name Racosperma, and the folks who have been studying gum arabic trees refuse to use Senegalia, then the broad definition of Acacia will prevail by default. Why not vote to keep it broad rather than have a whole bunch of people rebelling against the name changes?
My next preference is to embrace the extraordinary passions and nationalist fervour that have been stoked by the Acacia name change, and to propose a completely new genus name for the Australian species. So the Australian botanists don’t like Racosperma, fine, then appeal to the Botanic Congress members to vote to make an exception to the rule of priority and say that due to the popular dislike of the sound of the word, that name will not be used in relation to the Australian species. Instead, let’s celebrate the very Australianness of this distinctive yet hugely diverse group of Australian wattles by using an Australian Aboriginal name for the genus. That is to say, if the Australian botanists want to select the hickory wattle to be the ‘type’ species, then the genus name could be derived from the name given to this tree by Aboriginal groups from its area of original distribution. If botanists are determined to split the Acacia genus and the Australian advocates for splitting feel nationalistic about their species, then they should be genuinely nationalistic and give their species an Australian Indigenous genus name. This would be far more meaningful and respectful to the act of naming than hijacking the genus name Acacia from all those beautiful thorn trees that have borne that name for centuries, if not millennia.”
(Many thanks to Priya for this guest blog – the long version of a comment she posted to my previous blog)