taxonomy: the tragedy of nameless extinction

8/8/2019 Taxonomy: The tragedy of nameless extinction

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an a species become extinct even before ithas a name? Sadly, the answer is yes. Even

today.For all life forms to have a name that is un-

derstood the world over, we need taxonomy (ascientific method for naming species). For this,there should be skilled taxonomists, who are pre-pared to go through demanding field work andthe rigour of precision laboratory work before aspecies can be found and given a scientificallyvalid name.

That a species might vanish even before it has a

name is a cause for shame. If we have to conservespecies, the minimum that we should have is aname. Without a name for a species, we cannottalk about conservation of that species and

without taxonomy, species cannot have names.Though taxonomy was popular and ardently

pursued for a long period till the mid 1990s, at-

tention soon shifted to more modern ways ofstudying life on earth. Taxonomy gradually be-

came an old science which scientists with amodern outlook distanced themselves from. Butno scientist, old or modern, would argue againstthe need to have names for all species. Few wouldargue that taxonomy fell into disuse because there

were no new species to name or that we have onlysmall and minor species left. In the last five years,a new elephant, a new tiger and a new leopard

were added to the list of new species. None ofthem could be categorised as small or minor! The

last five years also saw hundreds of other life formsbeing described as new species. In science, thediscovery of a new species of a miniscule frog is asexciting as the discovery of a new species of gigan-tic elephant.

The simplest reason why we still need taxono-my is that we still have several species without

Taxonomy

The tragedy of nameless extinction

Only an active community of trained taxonomists supported

by liberal funding can document the vanishing biodiversity of India.The experience with amphibians shows that there are several species

awaiting systematic classification, says S.D. Biju

One of the many Western Ghats species that are still undescribed. PHOTO: S.D. BIJU

WILDLIFE


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names! The fact that new species keep turning upwhenever serious taxonomic explorations are un-dertaken is sufficient proof that we have recordedonly a part of the great diversity of life forms onearth. Taxonomists who diligently explore, oftenkeep finding new species in their area of interest.

Good quality taxonomic work is possible onlywhen there are good quality taxonomists. Goodquality taxonomists evolve in an environment

where good training and research grants are avail-able easily. Sadly for India, both these require-ments do not measure up to healthy levels.However, in spite of this, some areas have rec-orded taxonomic advances one of them is thefield of amphibians.

Amphibians an overview

The first step that some unknown amphibiantook on land created the first footprint on the faceof solid earth. An amphibian is the first actor inthe evolution of life on land. However, fiction andscience seem to beunited in denyingpride of place to am-phibians. Storytellersand scientists have

perceived amphibiansin a negative manner.Fairy tales requirethat a frog (portrayedas ugly) be trans-formed into a prince(who is obviouslyhandsome) for a story to have merit. Even Lin-naeus, the pioneering taxonomist, did not namemany amphibian species. Perhaps he too was in-

fluenced by fairy tales and considered frogs to befilthy.

Fortunately, amphibians seem to have wrig-gled out of this handicap. Globally, the rate ofnew species descriptions have shown a healthyincrease. Among vertebrates, more amphibians arebeing described than any other kind of animal.

Amphibians in India

Compared to other south Asian regions, in-

dependent India was not very active in amphibianresearch. Much of the work was not systematic.However, R. S. Pillai and his colleagues created animpressive taxonomic inventory for the Indian re-gion and published 14 species. The yield from allother workers put together comes to only 71.

Of the current 272 known species, about 65

per cent were recognised before 1947 by colonialresearchers. The years between 1947 and 1973

were a period of hiatus in amphibian species de-scription. From 1973 till the end of 2000, am-phibian research was mainly led by two ZoologicalSurvey of India researchers, R. S. Pillai and S. K.

Chanda. A number of papers specific to amphib-ians of the region were published between 1975and 2008. This was followed by books authoredby S.K. Dutta (1975), S. K. Chanda (2002), J. C.Daniel (2002) and R. J. Ranjit Daniels (2005). InIndian amphibian research, the contributions ofIndraneil Das who described 10 new species, andS. K. Dutta who described five species requirespecial mention.

Indias 272 amphibian species include at least

242 species of frogs and toads; at least 29 differentcaecilians (legless amphibians); and a single spe-cies of salamander (Tylototriton verrucosus) inthe mountains of the north-east. The amphibiandiversity of India is distinctive in its identity, di-

versity, and endemism.India currently holds171 species entirely re-stricted to India. High-er taxonomic-level

endemism clearlymakes this regionunique in the Asiaticregion, with four fam-ilies (Micrixalidae, Na-sikabatrachidae,Ranixalidae, Uraeoty-

phlidae), and nine genera (Gegeneophis, Indira-na, Indotyphlus, Melanobatrachus, Micrixalus,Minervarya, Nasikabatrachus, Nyctibatrachus,

Uraeotyphlus) being endemic. In India, like inmost of the tropics, the precise number of speciesis not stable because new amphibians are beingdiscovered and many of the hidden names areelevated to species status from synonymy at a re-markable rate.

Recent evidence suggests that the relativelyslow increase in the number of Indian amphibiansin the 20th century is explained by lack of effortand appropriate techniques rather than there be-

ing no new species to describe.Almost 45 per cent of all Indian species cur-

rently recognised were described during the 19thcentury based on preserved museum specimens.Moreover, due to incorrect identification, severalspecies from Sri Lanka, Myanmar, Malayan archi-pelago, and Java have been regarded as members

Recent evidence suggests that therelatively slow increase in the

number of Indian amphibians inthe 20th century is explained by

lack of effort and appropriatetechniques rather than there being

no new species to describe.


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of the same species with the Indian amphibianfauna. Preliminary research clearly indicates thatseveral Indian species common to other bioge-ographic regions are incorrectly identified and areendemic to India.

Trends in rates of amphibian description:Global: In 1992 the total of known amphibian

species stood at 4,533. This figure climbed to6,312 in 2008. This is 34 per cent growth duringa 15-year period. In the last decade (1990 - 1999),810 amphibian species were described.

All the new species are actually old speciessince they were always living out there in theirchosen habitats. Since new species will not seekout taxonomists, taxonomists have to seek outnew species. And when this simple truth is realisedand taxonomists become active, new species

emerge with gratifying regularity. This growthtrend is fortunately continuing (compare thesefigures: In the decade of the 1990s, 81 species

were described; in 2005 alone more than 200 spe-cies were described). This sharp contrast is so-mething that even those working outsidetaxonomy can appreciate.

This exceptional taxonomic progress wasachieved through a combination of extensive fieldexploration in tropical regions by an increased

number of herpetologists, and routine applicationof molecular techniques.

My work is predominantly in the WesternGhats. The work includes surveys of montane andother highland environments. The studies discov-ered over 100 novelties and was published in2001. In 2003, a new frog family was discoveredtriggering excitement in both academic science

and popular science. The next four years gave 28new species. Looking at this trend, I will not besurprised if the number of Indian amphibian spe-cies crosses the 400 mark.

Trends in taxonomy

All the complicated processes within taxono-my are for identifying already described species,naming new species and determining relation-ships among species.

The small bits of taxonomic advances finallycome together like pieces of a gigantic jigsaw puz-zle to show us glimpses of how our worlds biodi-versity is organised.

Taxonomy has become more active in recentyears. In the post-Fauna of British India period,that is, in a span of 100 years, only 80 species ofamphibians have been described in India.

Taxonomy uses advances in other fields to de-velop more precise tools and techniques for its

own use. Identification of organisms throughcomparison of short DNA sequences has recentlygained attention. This is called DNA barcoding orDNA taxonomy. DNA barcoding allows relativelyrapid identification of candidate species whichmay turn out to be new species, and on whichnecessary morphological taxonomic research canbe efficiently focused. Combining systematic fieldcollections with DNA barcoding offers an oppor-tunity for taxonomic acceleration in amphibian

research.Taxonomy should not be based on DNA dif-

ference alone.Advances like the molecular approach are not a

replacement for more traditional taxonomic ap-proaches. If funding agencies are fascinated onlyby what is new, traditional and critically neededskills and knowledge could be pushed towardsacademic extinction.

I believe that at least some of the new molec-

ular systematists choose to work in that area sincethat is where funding is available. If the winds

Number of species in three major ordersrecognised from India.

Taxonomy uses advances in other fields to develop more precise toolsand techniques for its own use. Identification of organisms throughcomparison of short DNA sequences has recently gained attention.


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continue to blow only in the same direction, itcould be detrimental to taxonomy as a whole.

While molecular systematics is important, it isequally important to allocate funds for discov-ering and describing new species. There does not

seem to be any other method for finding newspecies.

Amphibian conservation

Amphibians are hardy creatures, having usedland for about 360 million years during whichtime, they survived at least five mass extinctions.

When the mighty dinosaurs disappeared, thehumble amphibians survived. But what 360 mil-lion years and five mass extinctions could not

achieve, humans can. Amphibians, in their life cycle, need to use

environment in both land and water. Human ac-tivities are taking away the land and water fromamphibians. Where land and water are still avail-able, they are getting contaminated by variousenvironmental pollutants. Humans have also in-

terfered with finely balanced ecosystems by in-troducing exotic species. In many instancesamphibians had to pay the price for such irration-al introductions. Thus the primary source ofthreat to the successful lineage of amphibians is

the more successful spread of humanity. The listof threats to amphibians keeps growing thecurrent additions are climate change, infectiousdiseases and chemical contaminations.

Twenty three per cent of amphibian species inIndia are threatened with extinction (Global Am-phibian Assessment - GAA by IUCN/CI). Severaldescribed species are not to be found now and arepossibly extinct. There are several specific threatsto amphibians.

Modification of natural habitats, expansion ofplantations (both non-native timber and coffee/tea estates), commercial logging, extensive extrac-tion of forests products, mining for ores and gemstones are all significant assaults on amphibianenvironment. While there are no records to datein India of the disease chytridiomycosis, which

Waiting for a name a beautiful forest frog from Manipur. PHOTO: RACHUNLIU G KAMEI

The core philosophy of conservation is to protect the habitat.Species will then conserve themselves. This applies very well to

amphibians too. Many threatened amphibian species might havefound sanctuary in national parks and reserves.


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has been implicated in the considerable declines

of amphibian communities in Latin America andAustralia, there is a need for field surveys to con-firm absence of this pathogen in India.

The core philosophy of conservation is to pro-tect the habitat. Species will then conserve them-selves. This applies very well to amphibians too.Many threatened amphibian species might havefound sanctuary in national parks and reserves.But all amphibian species may not be so lucky.Urgent work needs to happen to characterise the

habitat requirement for all threatened amphibianspecies and protect those habitats.

The more we understand a species, the betterwe are able to conserve it. Literature review clearlyshows that what we currently know, does not pro-vide sufficient knowledge for evidence-based con-servation.

Data Deficient is an impressive term which inplain language is simply a confession that we donot know what we need to know. Seventy-six spe-

cies from India are Data Deficient. Data Deficientis a sweeping term that embraces insufficientknowledge on many critical parameters. These pa-rameters include taxonomic identity, distribution,threats faced, locality of first collection and manyothers. Sometimes even the type series is lost ormisplaced. This is the case of species which at

some point in time were recorded. Many unrec-

orded species certainly have suffered the ultimatetragedy in biological science - namelessextinction.

Charting a course for conservation

Sometimes advanced technologies in scienceblind us to the simplest of common sense ap-proaches. While charting a course for conserva-tion, common sense tells us that first of all weneed to be clear as to what is to be conserved. My

extensive field work is one of the efforts in thisdirection.

There are many gaps and also inaccuracies inexisting knowledge. Many morphologically dis-tinct species have not yet been scientifically docu-mented. Intra-population structure of many wellrecognised species is poorly known. It is becomingincreasingly clear that some of the taxa that areconsidered to be common and widespread in In-dia may actually represent cryptic species com-

plexes groups of similar looking taxa that formdistinct evolutionary lineages.

Some 360 million years of existence on earthdoes not provide amphibians the immunityagainst extinction in this decade or the next. Weneed to take rational steps. These are possible only

when we have sufficient knowledge. Knowledge

The purple frog, an amphibian that survived the extinction of the dinosaurs. It was described from the Western Ghats. PHOTO: S.D. BIJU

Data Deficient is an impressive term which in plain language issimply a confession that we do not know what we need to know.

Seventy-six species from India are Data Deficient.


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comes in through research and hence research hasthe highest priority in amphibian conservation.

India is a huge biogeographic region. For re-

search in this region, we need large numbers ofgood quality researchers. It is an academic chal-lenge to produce good quality researchers and toconduct high quality research. Similarly, it is anadministrative challenge to find funds for betterrepresentation of taxonomy units in universitiesand funds for taxonomic studies in field and lab-oratory.

Professor Quentin D. Wheeler of The NaturalHistory Museum, London, said, Funding for

taxonomy is inadequate and largely diverted tostudies of phylogeny that neither improve classifi-cations nor nomenclature.

This shows that the roadblocks to taxonomyare not just an Indian phenomenon. Somewherein the progress of biological sciences, we seem tohave taken a wrong turn. It is time that this is

corrected and taxonomy given its due importancethrough firm steps. This would include establish-ment of faculties for taxonomy and also sufficient

grants for taxonomic research. What is needed is clear. The question is

whether we have the will and the skills to advancethis important area of science.

Sweeping habitat destruction is endangering amphibians. This site is just a kilometre away fromIndias smallest frog species. PHOTO: S.D. BIJU

S.D. Biju is Reader, University of Delhi. He hasdescribed 31 new frog and plant species, including thepurple frog familyNasikabatrachidae. His website is:

www.frogindia.org

taxonomy: the tragedy of nameless extinction

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