Does taxonomic inflation benefit or harm wildlife conservation?

Hi,

I think this is a difficult question to answer, also because you put it in two different contexts. The first one is to get additional funding and resources (or not) with the addition of several "phylogenetic/genetic" species or subspecies and the second one is the conservation aspect. I think that for the conservation aspect, it is rather important to know what you are trying to conserve and I would say that any evidence of new subspecies or species is a valuable info. Of course, some of these genetic evidence just show some on-going isolation process with most of the time hybridization, which complicate further management and conservation, but it is still rather important to note these things.

For the financial aspect as such, I think science is anyway living a bad period, with lots of conservation ideas, but very few practical funds... Studying and conserving nature is a big challenge which we are far to reach and I hope this will change in the future.. But I don't think that the Taxonomic inflation should affect fundings of research as with time we are likely to see more species appearing (theoretically) or more divergence, as well as more extinction..

We should explore the full range of species concepts - biological species, genetic species, morphological species, phylogenetic species etc., there is no right or wrong if we're in the framework of biodiversity conservation for our future generations.

I believe there is no an obvious answer. In some aspect, so called "taxonomic inflation" is a harm since it hamper the work of conservation practitioners that are facing with endless taxonomic fluidity and changes. Besides, it may have effect on legislative acts intended to protect a list of taxa known under their "old" Linnaean binomens. On the other hand, "taxonomic inflation" as such is not an absolute evil since in some cases it is based upon molecular evidence of cryptic speciation or even intraspecific phylogenetic lineages that well be worth to conserve. Thus, we need a particular answer in each concrete case of presumed 'burst' of taxonomic names.

The question is both interesting and challenging. Interesting in that the subject of 'taxonomic inflation' is recent and debatable. For instance, it could be a theoretical fact that new species are coming on board, but it could be equally true that because of new knowledge more species are being discovered, not that there are new evolutionary species. However, linking 'taxonomic inflation' to funding can be a challenge, but l think its good for conservation. In animal (wildlife) or vegetation conservation it is critical to know what species you have and their composition. Funding is actually attracted to this knowledge and this in a way could save critically endangered species. The problem comes when we indulge in misleading 'taxonomic inflation' just for the love of funding, as this distorts phylogeny and genetics.

Agree with the last point although it is getting more and more complex to integrate the large amount of info we can get...

Thanks for the interesting views. I guess a lot of the debate has to do with different opinions about what is the appropriate unit of conservation. Zachos recently argued that "...much of this taxonomic inflation is artificial due to shortcomings of the PSC and unjustified reliance on insufficient morphological and/or genetic data. Species splitting based on gene trees inferred from mitochondrial DNA only and phenetic analyses aimed at diagnosability produces particularly doubtful results that also create an unnecessary burden on the conservation of biodiversity because effective

population sizes of already threatened species are further reduced and genetic rescue is hampered, potentially resulting in an increased risk of extinction...."

Zachos's argument raises a few questions itself: Firstly, will we ever have enough morphological, genetic, ecological, distributional, behavioural or other data to say with certainty whether two taxa are distinct species or not. Proponents of the PSC have argued that at least their species definitions rely on unambiguous quantitative assessment and are therefore scientifically testable. Also, it might be true that taxonomic inflation reduces effective population sizes and thus extinction risk of species, but then again, if these inflated units are indeed "true species", increased concern for their extinction would be justified. I guess the bottom line might be that species are a man-made concept and we will never quite agree what is a species and what isn't it. That doesn't help conservation much though...

As in economics, too much inflation will probably be harmful. However, a little inflation is generally beneficial, and a little deflation may be useful at times as well. In the same way that we need reliable economic policies rather than boom and bust, we also need good taxonomy--well researched, soundly based, moderate, and stable. This allows better understanding of diversity and easier identification, which leads to better management. Conservation is too important for it to be used as a political football in the long-running arguments between lumpers and splitters.

Does taxonomic splitting dilute conservation efforts? As always, the answer depends on the context. Certainly, recognising two species of African Elephant doesn't make them any more common. Rather, it focuses us on the need to protect both Savanna and Forest forms, irrespective of taxonomy. Splitting widespread, geographically variable forms, such as the Mountain Greenbul or Olive Thrush (birds) of tropical Africa, into several locally endemic species, tends to result in an increase in Red Listed species. At first glance, this seems to splinter conservation efforts - this is the economists' thesis (The Economist. 2007. "Species Inflation: Hail Linnaeus" http://www.economist.com/node/9191545). This argument is misplaced, however, because species are not a specie (currency). Unlike minting currency or mining for Bitcoins, systematists describe species to reflect diversity in nature, not for our convenience. One aim of the taxonomic codes is to maintain stability of names. Arguably, taxonomic splitting is a source of instability, but this is no reason to regulate the number of species that should be described. Instead, the impact of new techniques, new insights and molecular data should be to shift our approach to conservation - towards prioritisation of areas, threats and species. In the case of the Mountain Greenbul each narrowly endemic species occurs in a local biodiversity hotspot, in the mountains of Cameroon, the Albertine Rift or the Eastern Arc Mountains. These tend to coincide with other endemics, both long-recognised unique forms and newly coined species, such as the genetically divergent populations split from the Olive Thrush. Our efforts here should clearly be on habitat conservation. Global and local threats, such as forest clearing, affect all species, regardless of names, and are more fruitful problems for economic theorists. Where direct intervention is needed for particular species we should weight our efforts according to their ecological and evolutionary distinctiveness. That said, even in the unlikely case of complete agreement on global priorities, for the foreseeable future most conservation funding will be spent as it has been in the past; on familiar forms, close to home.

The main objective of Biological sciences and conservation, where Taxonomy makes a great output...What matters is the truth...nothing else...This is a philosofical question aiming for prominence, more than for conservation concerns...

One more consideration. The concept of biological diversity is not equal to taxonomic diversity, or species richness. One may indicate much more aspects of diversity and more diversity units to conserve. In my opinion, recent "taxonomic inflation" is a part of a more wide movement to recognize in the Nature as many phenomens of diversity as possible. If it is true, then this 'inflation' is not a harm altogether; merely it arises as a consequence of our deeper undertanding of natural ecosystems. Rather, conservationists must take into account this taxonomists' activity (including, of course, erroneously described species) than otherwise systematicists should satisfy conservationsts' needs and demands. I am a taxonomists, that's why my response is rather "pro" than "contra" :)

My view is that we should be very careful with using the term 'taxonomic inflation'. According to The American Heritage Dictionary of the English Language, 4th edition, the verb 'to inflate' means: "a. To enlarge or amplify unduly or improperly; aggrandize. b. To raise or expand abnormally or improperly." The connotation is on 'excessive, undue, improper'. Thus, by labelling the current/recent increase in the number of species 'taxonomic inflation', we are, in my view unfairly and unwarrantedly, dismissing the thorough and important work of hundreds of taxonomists as improper.

You are mixing in this question two very complex problems. 1) How to define species and recognize them depending on the old and new systematic tools, and 2) How to achieve conservation if those species are not well defined/recognized. Such a difficult task. However, speaking from the conservation point of view, my opinion is that the species-oriented conservation is one of the most limiting strategies you can take. In part because the problem you are addressing, but also because that implies to have thousands of conservation plans/strategies/actions, one for each species (however, recognizing that is useful in very specific cases, as the panda or the California condor). So, perhaps is wiser to consider other conservation strategies, based on ecosystem, landscape, interactions or environmental services approaches, where the identity of species is not of a basal importance, but their funcionality as part of a whole system. Some specific-species (normally not affected by the taxonomic inflation problem) conservation strategies can be included in this perspective, because the focus species is considered as an "umbrella" to preserve habitat functionality.

Once said that, to answer your question, I think that the "taxonomic inflation" is probably more benefic that harmful for wildlife conservation.

Dear Erik,

I think and moreover even convinced that such question should not be raised. There should be no taxonomic inflation. I agree with the ideas said above that we make species hypothesis from as much evidences as we can get but this should be done on pure way searching for scientific truth, not having in mind how much funds can be denoted for protection of species. The consequences might be such that no funds for species conservation will be allocated at all if taxonomic inflation continues.

Jurate

As our understanding of nature improves, it is possible to discern the finer points of our objects of study, using different techniques. If new techniques enable the recognition of cryptic species, then that is certainly good. Too much of a good thing, however, is bad, so if every local variant is given species status, it does not improve our understanding of nature nor the credibility of science in the eyes of the general public (read exploiters). To my mind, the biological species is a valid concept, rather, the valid concept for species, since it reflects an actual situation rather than an imaginary one. To recognize populations that can produce fertile offspring and distinguish them from similar populations that cannot is a good goal. In this context, both the lumpers and the splitters have truth on their side, it is only the extremists that bring a bad name to both arms of the continuum.

In the context of obtaining conservation funding, if a population can demonstrably be proved to be reproductively isolated and threatened with extinction, then it follows that funders and decision makers will be morally obliged to make necessary arrangements to preserve the species. If, however, decision makers know that the endangered population is only doubtfully a valid species, but has been raised to species rank merely to attract funding, it follows that not only that taxon but others, too, will suffer from the decision makers' understandable skepticism.

As Carlos states above, what matters is the truth...that is what science is all about.

I think that if a species is clearly a separate species then there is no inflation, however where two populations of a species appear to be genetically divergent, but interbreed readily, it becomes much harder to apply effective conservation management actions.

I worked on the recovery team of one of Australia's rarest birds - the black-eared miner (BEM) for several years. It is closely related and hybridises with the yellow-throated miner (YTM), which is a widespread and abundant species **. The BEM is restricted in range to a relatively small area of mallee in semi-arid parts, but in more mesic areas the YTM occurs and they are sympatric and hybridise and only a handful of people can distinguish hybrids from the YTMs. Huge sums of money have been spent on the BEM, land has been reserved to protect it and one of the recommendations proffered was to cull YTMs. Little evidence could be provided that the conservation actions had worked (other than the persistence of the species), but I expect the money spent on BEMs would have been more effectively directed elsewhere.

** NB - the genetic study that separates the two was published in a general readership magazine and not a peer-reviewed journal, and otherwise they have been separated based on minor phenotypic variation.

As a taxonomist working on birds, I am disgusted by the term ' taxonomic inflation' because it is a deliberate misrepresentation of the scientific basis for taxonomic change and denigrates the hard, underfunded and often unappreciated work of taxonomists.

If the task of taxonomists is to reconstruct the tree of life, and classify and name its branches, then taxa (including species) are scientific hypotheses. These hypotheses are being documented in increasing detail.

The claims made by Isaac et al (2004) that species numbers of charismatic groups such as birds and mammals are increasing due to (i) reinterpretations of available data (as opposed to new taxonomic data) and (ii) a change in species concept, were not based on any quantitative data, and were subsequently shown to be false. See my paper:

It is important to realise that between 1900 and 1950 about 10,000 bird species were lumped in large polytypic species, thereby reducing the number of birds by more than 50%, often without any evidence whatsoever. Only in recent decades are some of these being reinstated as species, now typically based on multiple lines of evidence and published in peer-reviewed journals.

The claims made by Isaac et al. (2004, 2005) in their papers in Trends in Ecology and Evolution that such newly-split species are 'more of the same' (pseudoreplicates), are 'not real', represent 'inflation' (literally 'less-value-for-money') and are 'bad for conservation and macroecological studies' are highly ignorant of the actual taxonomic process, and merely underscore that these people have no direct experience in taxonomy. I consider the 2004 Isaac paper one of most damaging attacks on a profession that is already struggling for recognition, if not survival.

Although Isaac et al's 'taxonomic inflation' hypothesis has been falsified, the term unfortunately has stuck, and people are now using it for whatever taxonomic conclusions they don't like. If you see a bad taxonomic paper, just call it that: bad taxonomy.

An interesting question, and one that will probably forever elude an answer as formulated. This is for two reasons. Firstly, the question is framed as an eithor/or, whereas the answer is probably "neither" or "both" - it's a good example of what Schumacher called a divergent rather than convergent problem. Secondly, as has been pointed out, it's a richly layered question which needs to be unpacked into separate (hopefully answerable) questions.

The first problem. Cases can undoubtedly be raised where increasingly fine splitting of taxa will benefit conservation by drawing attention to significant populations that are worthy of conservation. Cases can also undoubtedly be raised where increasingly fine splitting of taxa will disbenefit conservation by diluting limited resources, or setting up "taxonomic fatigue". We have an interesting situation here in Western Australia, where we could easily triple the already large number of recognised taxa through recognition of disjunct and (morphologically or genetically) variant populations of widespread taxa, most of which would be conservation-ranked. Would this benefit or disbenefit? - probably both, in different ways.

The second problem. Taxonomic recognition of species is a complex endeavour, and after centuries of practice little better than rules of thumb can be applied to the central question - what's worth recognising? There are two reasons why "taxonomic inflation" is newsworthy. Firstly, steady work by generations of taxonomists is steadily increasing the numbers of species. Is this inflation, or steady growth? Secondly, new technologies and methods have provided us with ever-more-powerful "microscopes" for seeing fine levels of pattern. When we relied on morphology, there was a more or less fuzzy horizon beyond which we couldn't sensibly go (debates between splitters and lumpers nothwithstanding). With molecular tools we can now see patterns that were once invisible. An open question is: if you can see pattern - a certain level of divergence between two populations, or a certain degree of branch-depth on a phylogeny - should you name it? The pattern analysis is the easy bit. The judgement call as to whether or which recognizable chunks of pattern should be named is the hard bit, and this is the difficult and necessarily messy and compromised domain of taxonomy.

I feel that the recent increase in number of recognized taxa may only benefit conservation. Global conservation money is not a pool that is divided evenly for the conservation of each and every threatened species. Therefore, if we have more species, we will not end up having less money for the conservation for each one. Unfortunately, the global conservation money is already limited and is allocated for the protection of only a small part of the threatened species. Having more species will probably not change significantly the number of species whose conservation is funded by global grants or organizations, although this will reduce their proportion out of all the threatened ones. On the other hand, Governmental or local NGO funding, and even corporate funding, may only increase due to the recognition of new species. These organizations usually will not fund projects in other countries/regions, but if a new threatened species is described/found/recognized in their region of activity/responsibility, they now might allocate money for its conservation. The same will probably apply for community action and willingness to contribute to conservation efforts.

Benefit!

Inflation is never a sustainable practice.

:) just remembered when I saw Noam's address that taxonomy is the oldest profession (ahem), because it originated when God got Adam to name the plants and creatures He brought to Adam (Genesis 2:19) . That we have not managed to name all the animals and plants until now underscores to laggardly pace at which it is progressing, but remember, (atheists please stop reading at this point), it is God's work we are carrying forth and what used to be known as the 'oldest profession' is hereby delegated to the 'second oldest profession'. Having said that, I think we should all gather under one roof rather divide ourselves into sects... :)

The term "inflation" is derogatory and misleading. Recognizing phylogenetic rather than biological species implies that we can perceive not just the species as conservation units, but the clades they belong to. This means we can include historical (evolutionary) criteria for conservation in addition to endemism or charism. Conflating phylogenetic species together just because they happen to interbreed brings a loss of valuable information.

I believe I agree with everyone above. Yet, as an ecologist that has dabbled quite a lot in taxonomy, I think we may also be confusing efforts to clasify nature with the environmental significance of a species. They are rather separate endeavours. Taxonomy is a discipline that has been revolutionized by modern technology and needs to find its way in the amazing and sudden growth of available data. Even a certain degree of agreement on what defines a species seems far, far away. What a species, or any taxonomic group we choose to take as a study subject, means to the ecosystem in terms of conservation importance is a different matter that does not necessarily depend on how we group or split it said taxon.

I have worked in conservation in the UK for 10 years, and there is a movement away from single species management and into landscape scale conservation that is often funded by socio-economic streams (mainly because that is where the big bucks are). These projects are often large and multipartnered and tend to be more focused on habitat functionality than individual species management. As such individual species needs are considered within the wider context of these projects, so in theory the splitting of species should not have a significant impact on funding streams in this instance.

To begin, I agree with Sangster and his disgust with the term "taxonomic inflation." It's a bogus claim because it implies species are arbitrary things we conjure up or dismiss at will. Species are real. They exist without the need for us to say they do. Our job as scientists is to discover them, to propose hypotheses about them. There is no inflation, only hypotheses about our perception (based on data and analyses) of existence. Given that, there is no reason to discuss if "inflation" hurts or helps conservation efforts.

According to two of the leading stakeholders in wildlife conservation, IUCN and CI, the answer to your question would appear to be that taxonomic inflation is beneficial to conservation.

In the 2nd volume of Mammals of the World, a book series published with the support of the IUCN and CI, they adopted a recent revision of the bovid taxonomy that increased the number of extant bovid species from 143 to 279. A case, colleagues and I have criticized as a severe case of taxonomic inflation (see Heller et al. 2013, Sys Bio).

A number of posts above (from taxonomists mainly) disagree with the term and find it offensive to the “hard, underfunded and often unappreciated work of taxonomists” and in scientific questionably cases, suggests calling it “bad taxonomy” instead. I do not mind changing the terminology, but that does not evade the problem of the detrimental effects that bad taxonomy/taxonomic inflation impose on wildlife conservation.

In the end, I think, to answer your question, we need first to agree on what level of wildlife diversity we aim to conserve.

At the bottom line, we need to decide whether or not we can accept a species to encompass populations with fixed inheritable differences (of any kind). The Phylogenetic Species Concept (PSC) is often cited as the cause of taxonomic inflation as such fixed differences by definition makes a species. All population, aggregations of individuals, subspecies, ecotypes etc. that fall under this criterion of the PSC are raised to species level and, in turn, lead to inflated species lists. This will not have an effect on wildlife conservation exclusively, but any discipline where species is the currency. I second the post of C. Stapleton, that a little inflation of a currency can be beneficial, but harmful in the extreme.

In my opinion, stable species lists are not preferable but when splitting frenzies run wild, the described diversity we are left with have lost any meaningful connection to the underlying evolutionary process of speciation and will almost exclusively be harmful to wildlife conservation.

There is no such thing as "taxonomic inflation" as non-taxonomists often would like to label them without understanding or making any taxonomic analysis of subject species. Taxonomic research has nothing to do with its application for conservation or any other purposes. As there are many new tools, morphological, behavioral or molecular, for taxonomy of species and its related cohorts, most sibling species or infraspecific variations are clearly analyzed and their relationships can be determined. However, as genetic variation that is the result of evolution at the population level continues by infraspecific evolution, their phenotypic variations, namely morphological and behavioral level, are in continuum among populations. As a result, infraspecific boundary is determined by taxonomic specialist based on critical taxonomic analysis of these taxonomic characters which does not make taxonomic inflation. Ke Chung Kim

Since I have been an avid supporter of the biodiversity studies and feel that the more we know of the flora and fauna that we are better equipped to understand the role and importance of that species. How many species may have already disappeared in threatened areas such as tropical forests and other fragile areas. Do we know what chemicals or compounds from these species that might be important in our own survival. Taxonomic knowledge is always important when what we now catalog may soon be gone.

I do not agree with the views of "Taxonomic inflation" . The reality is taxonomists throughout the world become "an endangered race". (The taxonomist - an endangered race. A practical proposal for its survival. By- Wägele et al. Frontiers in Zoology 2011, 8:25). Under this condition some people look for quick solution to conserve biodiversity without knowing the organisms. As a result success is almost nil from the sustainable point of view. However, they are getting huge amount of money, preparing very quick reports. They need this type of publication (Taxonomic inflation...) to be more funded without doing serious works. I think this is one kind of conspiracy in the filed of Conservation Biology.

Species and Conservation are both human concepts. Nevertheless we need to know what exists in this planet for several kinds of arguments. Conservation is only one of them. Though we still need to know what is there to conserve. In this sense taxonomy is essential. We can debate concepts and species endlessly but still, as speciation and extinction, the hypothesis are not static. Species are hypotheses and most politicians and scientists should have this idea into account when planning conservation.

Personally I do not believe in taxonomic inflation. There are both sides of the coin, the species still to discover and the species that were named and do not exist. If in the beginning a naturalist has the tendency to consider everything as different species, with time and a better knowledge of the biodiversity throughout space there is a tendency to join the similar specimens. It will depend on the level of knowledge of the studied taxa.

Conservation will always depend on the level of taxonomy but funding is given preferentially for conservation. We should decide if we prefer to conserve or to know because extinction is happening on species we still do not know.

My only concern is that the lumper vs. the spliter side of taxonomist forget that there are unique plant /insect associations that by separating out one from the other may result in to two extinctions than just one. I do think careful reviews should eliminate duplicate or defining a species that is in fact already identified. Nonetheless we have come a long way from just calling all pigeons, pigeons, hence the lack of respect when the passenger pigeon was over hunted. Our lack of respect for the organisms right to survive at its own capacity is ignored. There will be natural extinction, and we often cannot control but we should show enough for the species we eliminate to attempt to name and understand its habits and ecosystem.

Thanks for your comments. Species is human concept of what's real as "Homo sapiens Linnaeus" refers to humans and "Pediculus humanus" is the species name for human body louse. As we talk about biodiversity or organisms, we should get out of the anthropocentrism with a tunnel vision to be natural and true to our knowledge. Ke Chung Kim

It's seem important (as molecularist) to define the notion of independent genetic entity. Working mainly on Arthropods, I realized that within "species" you may have fully discrete genomes....how to name these entities (see all the literature of James Mallet) subspecies/semispecies/sister species ?

Coming back to conservation what is important....? protect a phenotype or a genotype? What are the risks to loose a "phenotypical species" when you are not taking care of the whole range of independent genotypes with a same phenotype? Are actual patches of species ("metapopulations"?), (often bearing particular genotypical identities) represent a fragmentation process or a natural evolution?

very interesting topic anyway.

Cheers from Lluc

Taxonomic excesses or poor taxonomy or whatever you call it, can either benefit or harm wildlife conservation. It depends on the organisms involved in specific situations. Taxonomic inconsistencies can arise from incomplete understandings of organisms, even by well trained intelligent and dedicated researchers with great insight, who have to work with what has been collected in the past plus whatever they are able to find themselves in the wild. The latter may be limited not only by the ability of collectors, but also by funding, weather, the time of year. growth pattern and maturity of what they find, opportunity and just plain luck . They might just miss a significant population because they turned left instead of right while collecting or didn't visit another region.

On the other end of the scale is a rush to name something without carefully considering the known limits of wild relatives of the organism by examining all available material within the next higher taxon level for a broader geographical region than the one of interest to the researcher, hopefully across all regions where the relatives are found. This can be time consuming and complicated, and underscores why specialists are still needed to do this. Often poorly understood taxa also have poorly understood relatives, adding to the difficulty of the task. Over time, as more specimens are collected for any given group of taxa, it is legitimate to periodically reconsider the published described boundries of distinction between these near relatives, especially in poorly understood groups, groups with a lot of new collections since the last treatment, and where rapid changes are occurring that may affect natural selection. Personally I advocate adding protection for rare kinds of ecosystems, in addition to and not instead of protection for species. I have been told that any change to existing protection for species is a bad risk., as reopening that door is likely to result in a weakening of protection overall. That is based on the history of up-hill fights that took place to get the current protections in place and the intensification of competing economic interests through time. Because the laws are what they are, there is definitely pressure on those naming new organisms to give what might get a variety designation, a distinct species designation instead. To me, this should only be considered a legitimate option if the organisms themselves can be interpreted either way equally, based on the data. It is important that those depending on taxonomic identities for research and policy have faith in them. Much of the problem you are addressing is not due to poor taxonomy, but due to a poor understanding of what taxonomy is and why even good taxonomy may be subject to reinterpretation at a later date as new material and new methods are found.

There are other things to consider as well that should complicate things further in our lifetimes but may eventually clear up a number of problematic taxa. Some groups of organisms contains species complexes, groups of taxa that show both signs of overlap and of distinction at the same time, which hybridization alone does not seem to fully explain. They may be distinct due to epigenetic factors as much or more than differences from distinct mutations. It has been shown that flowering patterns in plants, much of coloration in butterflies and the number and kinds of of legs in crustaceans are under epigenetic control. Flowering patterns can be inherited for more than ten thousand years, yet other epigenetic shifts are merely retained within tissue in the lifetime of an individual, or if inherited, are lost after very few generations, making those epigenetic shifts taxonomically insignificant. There are multiple mechanisms by which these inherited differences, which are not due to mutations, can occur. Most of them are based on patterns of how often and at what stage of development particular genes turn on, in inherited patterns. Only one of a multitude of factors which can cause shifts in these inheritable patterns can even be seen with special sequencing, the methylation of c-DNA. Other ways epigenetic shifts occur are much harder to follow but can still be very signficicant for meaningful distinctions between species. The incorporation of this kind of information into species concepts is in it's infancy, even pre-natal. Classical taxonomy is still needed to address these distinctions, which require persons familiar with a wide sample of the group in question. Scientists as well as others forget that even the most cherished paradigms are just that, and that we should expect them to be replaced as more information is found. Consider good taxon names and descriptions, if not taxon themselves, to be paradigms - the best possible explanation after careful consideration of all available data at a given point in time. Hope this helps.

It is beneficial

In New Zealand the experience of taxonomic inflation was hastened by the ill conceived idea that subspecific ranks automatically could be collapsed into the assumed "parent" species rank irrespective of whether any research had been done to confirm that assumption. The idea was pushed by conservation concerns that New Zealand could not save everything and thus species not lower ranks were the unit that must be managed. The result was (as one would expect) a drive toward recognising subspecific taxa at the rank of species - which oddly, was not necessarily a bad thing where our flora was concerned. Indeed it pushed those seemingly or widely accepted "good" species that had been described as subspecies or varieties in the 1950s and 1960s and left to languish there to the more appropriate rank of species. Further it actually highlighted how few "active" biosystematists were left in our country, forcing people to revisit the need for better biosystematic information. While taxonomic inflation can undoubtedly be a serious issue, in New Zealand at least it mostly proved a God send to reactivate the wider concern that to verify untested taxonomic assumptions bought about by conservation needs, we needed to have a broader base of expert taxonomic opinion, thereby initiating an ongoing push for better funding into taxonomic research and teaching this science again at our universities.

However, the need for better funding into biosystematics here is still ongoing....

Thanks P.J.. Good to hear that the taxonomic revisions in New Zealand had overall positive impacts on both conservation and systematics. My experience working as a taxonomist and conservation scientist in SE Asia is similarly positive with regard to the "inflation issue". Many mammal species had been recognized in the 18th and 19th century, but all merged into 2 or 3 species in the middle of the last century. Subsequent recognition on the basis of molecular and morphometric studies confirmed that many of the original species were indeed good species (whatever that is). Wild pigs in SE Asia, for example, went from 1 species in 1830, to 48 species in 1910, to 3 species in 1940, to the presently recognized 11 species, and further taxonomic revisions are ongoing. Without these recent taxonomic updates there would be no conservation program for the Critically Endangered Visayan Warty Pig, a species from the Philippines which separated from its sister species millions of year ago. Similar examples abound and many of SE Asian mammal groups are in urgent need of taxonomic revision. Undoubtedly this will lead to many new species, many of which will be endangered, but that is the reality in a part of the world that has had extremely high levels of speciation under relatively stable climatic conditions, but major palaeogeographical change. This is quite a different setting from the glacially driven (sub)-speciation processes in boreal environments in the USA and Europe that has influenced so much taxonomic thinking.

Agree with EM. In Borneo, we have discovered and had published several cryptic populations and genetic species of small mammals; one being recently described and another in review process. Genetic species and subspecies should follow the recommendations by Baker and Bradley (2006). The Pleistocene and LGM events facilitated speciation in SEA. Biodiversity in SEA is underestimated and that could be the major reason for an adequate long term research funding in Borneo and SEA.

Well as ichthyologist I think it is highly beneficial towards species conservation which ultimate ends in habitat conservation.

As one of the authors cited by E M in his original question, my position is quite clear. I must add that without proper taxonomic revisions and re-evaluation of species concepts (in mammalogy, at least) the long-term value of ex situ breeding programs should be equal to zero, except for a small number of organisms were subspecies were considered important (orangutans, tigers, giraffes).

Furthermore, I must add that new cryptic mammal species are presently being described or re-evaluated in Europe too.

I just received a new publication on this topic, which should interest quite a few of you who have answered my original question: Cotterill, F. P. D., P. J. Taylor, S. Gippoliti, J. M. Bishop, and C. P. Groves. in press. Why one century of phenetics is enough: response to ‘are There really twice as many bovid species as we thought?’. Systematic Biology.

Phrases such as the following indicate that the authors strongly disagree with "taxonomic conservatism", which is how they typify those who object to "taxonomic inflation": "Will political decisions by expert committees replace real taxonomy?", "This arm-waving about “taxonomic inflation” is founded on naive operationalism and worse.... and undermines biology", and "The logical solution lies in reviving taxonomy, in which there has been too little investment for far too long. No shortcut suffices." Happy reading

Forgive my ignorance of mammalian taxonomy, but if PSC is applied to Homo, does it still recognize one or numerous species? If reproductive isolation and subspecies are not valid concepts, then how does one explain the emergence of the Common Peacock butterfly (Papilio polyctor) from a captive bred population of the Chinese Peacock (Papilio bianor)? At present, this matter was resolved by treating "P. polyctor" as a subspecies of P. bianor. However, under PSC they would continue to be separate species. Then how would the information that P. bianor can produce P. polyctor be incorporated in the taxonomic framework?

I do not fully understand the term "taxonomic inflation". If taxonomic differentiation is based on genetical differentiation and corresponds to real differences in habitat conditions and biological traits of plants, then may provide basis for conservation of some taxa. My experiences in the genus Bolboschoenus: Formerly widely conceived species (B. maritimus) appeared to be a complex of several species differring in ecology (halophyte versus freshwater species), biological traits and area of distribution. It apperaed that some of these taxa are threatened and need to be protected, while other species is supposed to be potential expansive weed on arable land.

It just occurred to me that the effort to create artificial human lineages, perhaps best codified and enforced in the Indian caste system, would, in fact result in the creation of different Homo species in the long term, perhaps already, since it has been in place for millennia. They would occupy different niches (or habitats) in society, breed in artificially imposed isolation which would consolidate minor differences in genetic configuration and eventually satisfy all the requirements of the PSC to be called separate species! Viola! Of course, when you get down to it, there are hundreds of sub-castes recognized by the Indian government, which could not constitute "sub-species", since that would be an invalid concept, so we would have hundreds of Homo species in India itself!

Dear Peter,

Given that in your example you have not problems in having a big sample (this is a bit different when you deal with Nigerian Klipspringers or Somali oribi), it should be interested to see if you find statistically significan differences at morphological and genetic level between Indian castes (and subcastes). Good work!

I spent some time on this question a few years ago in relation to the taxonomic revision of seabirds. Recent DNA studies have tended to create island-specific taxa and have greatly increased the number of seabird species qualifying for IUCN red-listing (Gaston, A.J. 2001. Taxonomy and conservation: thoughts on the latest BirdLife International listings for seabirds. Marine Ornithology 29: 1–6 http://www.marineornithology.org/PDF/29_1/29_1_1.pdf).

To quote: "A review of the seabirds included in the recent BirdLife International compilation, Threatened birds of the world, shows that the number of species considered threatened or near-threatened increased from 45 in 1988 to 123 in

2000. Recent taxonomic changes have been responsible for some of this increase, with most of the taxa involved being recognized previously as subspecies. I discuss the role of taxonomy in making conservation decisions and suggest that we may be becoming too dependent on critical taxonomic assessments and that we should be considering a broader mix of taxonomic and ecological criteria."

My concern was that, without much change in the actual status of species, the taxonomic revisions had made it look as though the conservation status of marine birds had deteriorated sharply. In fact, for some taxa, the status of constituent populations had not changed, simply our perception of the situation had altered with new information. I think two responses to this situation are appropriate: 1. management of local species populations becomes more important in the preservation of overall biodiversity; 2. conservation also needs to take account of the relative isolation of different taxa, so that we place more emphasis on truly unique taxa occupying very distinct niches (e.g, in the case of seabirds, sheathbills, skimmers, tropicbirds) and perhaps less effort on poorly differentiated species (e.g. some of the large Larus gulls, crested terns, or Pterodroma's). These have always been important elements in prioritizing conservation action, but recent taxonomic splitting makes them especially relevant. The continuous process of evolution means that not all species show similar taxonomic and adaptive differentiation at a given point in time. We need to consider that when apportioning resources.

The consensus from a large number of replies would appear to be that modestly increasing the number of species distinguished is beneficial to conservation, without any judgement being made as to whether the increase is intrinsically sound from a taxonomic perspective. This is interesting, as the derogatory term 'taxonomic inflation' was originally coined as a weapon in the arsenal of lumpers, in their long-running dialogue with splitters, attempting to bring shame upon the splitters for their irresponsibility.

However, all those interested in effective conservation should rise above this sideshow. The basis for planning and management of conservation actions, as opposed to listings, should always be a unit that is appropriate to the individual situation.

Please read Professor Georgina Mace's article on this subject, in which she eloquently distinguishes between the 2 processes of listing and conservation action. She recognizes the difficulties of defining species concepts and boundaries, and champions a pragmatic approach to the difficulties arising from the need to force natural populations into explicit structures.

The role of taxonomy in species conservation. Phil. Trans. R. Soc. Lond. B (2004) 359, 711–719

Assignment of taxonomic rank should be understood as a mere hypothesis or opinion, likely to change at the time of the next revision. Incidentally, the adoption of molecular techniques and cladistics does not change this. Recognition of monophyletic groups based upon cladistic analysis does not assign any particular rank to them.

Taxonomic work is essential for biodiversity conservation, and funding is just as scarce. It is easier to fund research that leads to the description of new species, so there is another reason for splitting being beneficial to wildlife conservation.

The concept of "taxonomic inflation" misjudges the central objective of taxonomy; to identify and describe fundamental units of biology. Stability of names is an important but secondary objective (existing names are generally retained in splits). Regulation of the IUCN Red-List is not an objective, nor should it be.

There is no reason why a change in species concepts, arising from insights provided by new forms of data, should not change the number of species recognised. There can be few taxonomists who would refrain from recognising what they interpret as a distinct species, to avoid red-list inflation.

The economists' argument that species inflation devalues the currency of conservation (www.economist.com/node/9191545) is also misplaced. It presumes that the number of threatened species, rather than the nature of threats, determines allocation of funding. Species conservation actions may operate on several levels. Restrictions in trade or harvest methods benefit many populations of a group, irrespective of the number of species recognised. The IUCN Red-List criteria are based on quantitative correlates of extinction risk and strongly emphasize population declines over rarity (small population size). Any newly minted species that is assessed as threatened would previously have been a population in serious decline - often without recognition. Population interventions are better guided when all distinct populations are recognized, or at least impervious to the number of species recognized. A good example is Albatross, which, depending on the authority, comprise somewhere between 13 and 24 species. Public supporters, funding and management agencies recognize that Albatross are in trouble, irrespective of taxonomic concepts. Broad actions, such as changes to long-line fishing methods that reduce sea-bird mortality, benefit many species. All 22 species recognized by the IUCN are listed as either threatened or near threatened but these taxa vary in the degree of extinction risk, which provides a better basis for prioritizing population interventions, such as rodent control at remote island nesting sites, than would a less speciose concept.

That said I think there is a need for continual review of taxonomic decisions and the application of species concepts. In a perceptive paper Frankham et al. (2012: http://www.sciencedirect.com/science/article/pii/S0006320712002376) argued that species concepts based on indicators of reproductive compatibility and fitness are more meaningful than those based simply on phylogenetic divergence. This argument seems to me to have a lot of merit because it emphasises understanding of biological processes.

There's a difference between taxonomic inflation and actually discovering new species. Taxonomic inflation means conceptual inflation of taxa based on strict application of monophyly and applies to higher taxa more than species. The species concept is a different issue, because it regards our understanding what a species is, which becomes relevant in recently evolving species complexes that show distinct structure but no tangible way of clearly separating species. What happens in many cases, however, is that molecular data help to recognize real, well distinguished species where we thought were none, including parallel evolution of similar morphotypes etc. In some cases, this can increase species numbers by an order of magnitude or more. I believe that such discoveries should enhance discussions about conservation because they require us to go away from just protection species to a more integrative concept of actually protecting habitats. Ideally, both can be combined if if can be shown that diversity, including species richness, correlates with absence / presence of key species.

I do not see "taxonomic inflation" as a valid argument or description of the current explosion in alpha taxonomic hypotheses. As we progress through the history of evolutionary phylograms and taxonomic inquiry based on systematic zoology, phenetic and now cladistic stages of inquiry, I personally see a release of the former methods grip on maintaining conservative views on variation and novel adaptations.

One of the best approaches to test systematic and taxonomic hypotheses is to explore the fullness of the variation associated with closely related organisms contained within the groupings we explore. In the past, it would have lumped currently recognized forms within larger groups, thus proving what we wanted to test. Instead, with genetic methods we can facilitate rapid testing of concepts and splitting of variation especially among small, isolated populations that would never have had enough material to test using morphological methods. Among the misconceptions is that we understand and can classify species and that somehow the increase in knowledge has diluted this understanding. While we have strong working hypotheses based on morphological, genetic, and ontogenetic bases, we still have relatively few combined datasets for most popular groups across the full range of traits and data to produce a combined evolutionary phylogram. Recognizing that more complete datasets are the long-term goal, we usually default to a simple mechanism based on a single dataset type or limited group of forms to explain our hypotheses. More coordinated efforts are needed to expand beyond genetic approaches only.

I believe that the taxonomic explosion is instead based on more scientists focusing on the tree of life project and simply looking at these basic questions concerning life, especially among groups that have been poorly studied in the past. This is not devaluing the quality of our understanding, but like most of the rapid increase in new knowledge, more likely an expansion of our understanding based on rapid publication venues, super computers that fit on our desktops, and more novel techniques that assist in the derivation of hypotheses or testing of former thought.

In oceanic archipelagos like the Canary Islands, Madeira or the Cape Verde Islands the problem can be just the contrary: cryptic species considered identical to the continental relatives, so no attention (or very little attention) to them from the conservationist point of view. In many cases in-deep morphometrics and genetical studies have shown (and are showing) that these entities are endemic, to specific or subspecific level. This situation is very clear with vascular plants, but also with some birds. Recent examples are Gymnosporia cryptopetala (endemic from the eastern Canary Islands), initially regarded as identical to the common and widely distributed Maytenus senegalensis, or the new subspecies of Egyptian Vulture (Neophron percnopterus majorensis), endemic from the same archipelago. I think that future studies will split more endemic species and subspecies from their continental relatives,as oceanic islands (like the Macaronesian region) are generally very important biodiversity hotspots, in which a high proportion of the flora and fauna (in this last case mainly terrestrial invertebrates and reptiles) is exclusive. In any case, taxonomy needs to be independent from conservation issues, but many times taxonomy can change dramatically the degree of attention to endangered species, as we have seen in the Canary Islands.

Fully agree with Ruben (you may have a look also to papers of Anna Hundsdoerfer on moths of these islands).

It seems that we've got now to characterize genetically "populations" as they may represent undetected species or at least endemic (or isolated) subspecies.

Of course, it gives that in the field the management of conservation is then almost impossible....as for most of populations nobody knows their real status.

Taxonomic analysis of polytypic species could show the level and state of infraspecific evolution as its populations continually evolve, resulting in different state of genetic variation, which is natural genetic process, whereas conservation is usually anthropocentric and/or artificial. As a result, every wildlife species faces the changing environment, specifically in each wildlife habitats and territory and evolve accordingly without knowing predictive future outcome - some populations may benefit and others may lose to eventually become extirpated. What's so big deal about it under the influence of human culture by 7.2+ billion humans? Ke Chung Kim

Several people have pointed out that the words “taxonomic inflation” are inflammatory, but fewer responses question the utility of the question itself. “The crucial question is whether or not the increase in species-level taxa (often based on the use of a phylogenetic species concept) dangerously dilutes scarce conservation resources (more and more endangered species means less funding per species, assuming that resources are limited).” There are several built-in, and in my opinion unfortunate, assumptions here that limit the value of question. The first is that the question implies we perhaps should not do taxonomy if there is not funding to conserve what is described. As others have noted, this doesn’t make sense. Taxonomy has conservation implications, but the assumption is that conservation issues should have implications for taxonomy. Why? If something is described then that description is based on someone’s research into the question of whether something was distinct enough to be described and that was presumably peer-reviewed (and as has been pointed out can be re-reviewed and revisited). In this context, conservation is secondary to whether or not the taxon is distinct. The second assumption is that there will be less and less funding per species for conservation and that somehow this will result in less successful conservation measures. There is almost no utility to a figure of money spent/species because there are too many variables involved in how much is spent (or more frequently not spent) to conserve any given species, and there are plenty of examples of lots of money going to preserve populations of species, so taxonomy (e.g., species status) is not necessarily part of the equation for conservation. If conservation is not possible or fails for a population that is of debatable taxonomic status (perhaps depending on one’s species concept) is that really different than losing something where there is not as much debate? Why do we consider these two things qualitatively different in a conservation sense? Both are extinction events and as stewards of the planet, humans need to be aware of them, just as they should be aware when conservation is successful. The argument that comes from some conservationists is that “you cannot save everything.” But what we really should be asking ourselves is “do we really know what are we losing?” The clear answer from all the new studies describing previously unappreciated diversity is “No.” As for money for conservation being limited, this assumes that money solves everything. Awareness may be just as important for conservation as money. Maybe local people take pride in protecting the island of forest because it has an endemic species and no “conservation dollars” are ever spent.

I totally agree with John. Prioritising conservation targets can be done above the species level. Several years ago, working on speciose Rodents, I utilised the genus level to highlight conservation priority

The goal of taxonomy is not to increase or decrease the number of species but to find out which species exist and how they are classified. The application of phylogenetics clarifies whether species are evolutionary distinct and isolated or related to many closely related species, which may help to prioritize species conservation targets (see EDGE program of Zoological Society of London).  Based on IUCN red data lists, species that are not well known are usually less protected than those considered endangered, while the reason for them not being distinguished may be because they are too small, because their habitat is not easy to access, or because they are too rare. In many cases they were not recognized because they belong to a group of organisms that has not been well studied. Increase of taxonomic knowledge is important because we want to know what needs to be protected.