Faunal Resources in India: Introduction
Introduction
This is an extract from FAUNAL DIVERSITY IN INDIA Edited by J. R. B. Alfred A. K. Das A. K. Sanyal. ENVIS Centre, Zoological Survey of India, Calcutta. 1998 ( J. R. B. Alfred was Director, Zoological Survey of India) |
Classical taxonomy with the conservative outlook is yet to assimilate the modem trends in taxonomy. It appears to the beginners as a monotonous and less interesting subject without any applied value. The elaborate description, lengthy synonomy and specimen citation are helpful only to taxonomists. According to Mayr (1969) "If taxonomy remains circumscribed with the domain of identification of dead specimens without considering the mode and manner of life and liVing, the very charm of studying biology is lost" In fact, the taxonomy has been a core subject in identifying the biodiversity conservation component, agricultural pests, pollinators, diseases, as well management of commercial species including fish, crabs, lobsters, pearls and many more. Recently, it is gaining its importance in improving productivity by applying biotechnological tools and identifying the bioactive components (bioprospecting), identification of alien species, quarantine laboratories and biological warfare. Therefore, the trained field taxonomists who have genuine interest in understanding the faunal associations should compare with the museum based specimens and attempt to evaluate the conservation oriented, public oriented and consumer oriented fauna. The taxonomists should also understand the size, structure and number of populations under a given species in the areas of exploration.
The need for the conservation of biological resources and biodiversity assessment has increased during the last few years; taxonomic studies are being encouraged now. If taxonomy has to flourish and fulfill the needs of the society, there is an urgent need to generate more manpower to handle the increasing pressure on taxonomists. Training of taxonomists.and increasing the number of taxonomists is the priority agenda of the present century. Therefore, the need of the hour is the taxonomic understanding of the alternate sources of food, energy, drug, industrial raw materials, genetic resources, wild variety of animals for conservation and utilisation in breeding programmes, in view of habitat loss and fast depleting biological resources. The rich resources present in a few pockets such as hotspots are to be surveyed and inventorisation of the faunal components are to be taken up.
The origin of the word taxonomy dates back to 1813 by de Candolle, however, has its root in Greek "taxis" meaning "arrangements" and "nomos" meaning "law", where as the Systematics also has its origin in Greek but dates back to the time of Linnaeus (1735), 'Systema' meaning to systems of classification. It is universally agreed that" Systematics" includes the formal technical classification of animals. Simpson (1961) considers "systematics as the scientific study of the kinds and diversity of organisms and of any and aI/ relationships among them" He further adds that the classification of organisms is an activity that belongs exclusively to systematics, but exclusive relationship does not warrant equation of the two. Taxonomy is the theomtical study ofclassijicaiton, including its bases, principles, procedures and rules. With the inclusion of all biological sciences such as comparative anatomy, physiology, cytology, biochemistry, ethology, biogeography, ecology, and the study of relationships among various orgnanisrns in systematics, the scope of zoological classification has increased. Therefore, according to Simpson (1961), the zoological classification is the ordering of the animals into groups on the basis of their relationships, that is, of associations by contiguity, similarity or both. In contrast to Simpson's definition, Abbot, Brisby and Rogers (1985) and Hawksworth and Brisby (1988) regard the products of taxonomy as "a taxonomic information system comprising classification, nomenclature, description and identification aids" where as the systematics "is the taxonomy plus the biological interrelations-breeding systems, genetics, phylogeny and evolutionary processes, biogeography and synecology" Therefore, often the "systematics" and "taxonomy" are equated or synonymous. Accordmg to Minelli (1993), it is not a matter of dispute about the confines of the academic provinces but identifying the targets worth considering and problems worth solving. Further, this should result in improving knowledge and communication of results. Clasification of animals at all levels is only one of the functions of taxonomy. The other and more important function is to define animal populations in relation to ecological, genetic and non-morphological characters and to correlate these data with evolutionary processes.
Animal taxonomy is one of the earliest of all zoological disciplines and started as "Folk Taxonomy" to differentiate between economic plants and animals around the human settlement. The earliest available works on the classification of animals were by Indians, since it was written in sanskrit, these remained unknown to the western biographers and historians (Sinha and Shankaranarayan, 1955). Mention may be made of Charaka (600 BC), the father of Oriental medicine, who was the first to classify animals into four major groups viz., Jarayuja (Born from the uterus of mammals) 2. Andayuja (From eggs ego Fishes, Reptiles and Birds) 3. Svedaja (Born of moisture and heat ego Worms and Mosquitoes) and 4. Udvija (Born of vegetable matter). Prasasthapada (500 BC) also classified animals into Sexual forms and Asexual forms (Kapoor, 1998). A good beginnng was made by Aristotle (384-322 BC) not only in Taxonomy but also in the field of anatomy, ecology & embryology, who erected orders like Coleoptera, Diptera and Lepidoptera (Psychae). Aristotelian taxonomy proceeds by logical subdivision, in which member of a pair of taxa is characterised respectively, by the presence or absence of a chosen feature. He may thus be considered as "Father of biological classification". Jhon Ray (1627-1705) in his systematic work" Synopsis Methodica animnlium Quadrepede -dum et. Serpentine Generis" (1663) divided the animals into those with blood and those without blood, the former was again divided into gill & lung breathing animals. Infact the contemporary naturalists attempts to arrange animals in a single grade, Scala naturae on the suggestion of Aristotle, who believed that there was an inharent tendency among the organisms in nature to attain greater and greater perfection with corresponding changes in environment, which ultimately resulted in perfect gradation from lower to higher categories of animals. This gave rise to the idea of evolutionary thinking.
During the later part of 16th and in 17th centuries, more and more biological materials were collected and brought through voyages and collection trips from all over the globe. Several herbaria and museums were established in Europe; this provided an opportunity to scientists to evaluate and to understand taxa as the units of natural system. Carl Linnaeus published first volume of 11 pages in 1735 and introduced the hierarchical system of classification both in plants and animals. In 1758, Linnaeus published "Systema Naturae", propounding the concept of binomial nomenclature. According to the International Code of Zoological Nomenclature, it is considered as the starting point of the zoological nomenclature, as he emphasized the usage of hierarchal categories such as species, genera, family, order and class.
The publication of "Origin of Species" by Charles Darwin in 1859 led to the theory of classification based on evolutionary relationships between different groups. The similarities based on the homologous structure related to the common ancestry and dissimilarities based on the analogous structure are the result of adaptation and convergent evolution. The idea of common descent of various animals provided meaningful theoretical interpretations to taxonomic work. Darwin-Wallace Theory (1859)-Qrigin ofSpecies through Niltural Selection-was supported by Lamarck (1744-1829) on the basis of evolutionary thought and Cuvier (1769-1832) based on the anatomical features and extinct fossil types. The drawback of Darwin in explaining the inherited variation leading to speciation was overcome by Mendel (1822-1884), through his controlled experiments and cross breeding on garden pea, leading to the discovery of principles of heridity. These principles formed the basis for evolutionary and biological classification.
Taxonomists confined their studies mainly on the morphological characters, ignoring the intraspecific variations and most of their descriptions were based on single "Type" specimens. Michael Adanson (1727-1806) believed that the classification could not be based on single or even a few characters and believed in the comparison of many characters. Haeckel (1834-1919) introduced the phylogenetic tree based on embryonic development and propounded the theory "Ontogeny recapitulates the Phylogeny"; this was in close resemblence to the Von Baer's Law-"Younger the embryo, more closely it resembles the embryos in same stage of development" The concept of "New Systematics" was introduced by Huxley (1940) and Mayr (1942) to express that the species are a group of interbreeding populations in nature which are reproductively isolated from other such populations, thus creating yet another subject viz., Population taxonomy. The new systematics led to the re-evaluation of the species concept from the biological point of view. It may be said that the new systematics is not a substitute for the classical taxonomy but only complimentary to it. Therefore, taxonomists are forced to believe that all organisms occur in nature as members of populations and these cannot be studied and properly classified unless they are treated as samples of natural populations. This made the taxonomists to realise the importance of other characters to supplement the morphological characters for sound classification, commonly known as Biological Taxonomy. Peter Raven (1974) summarises "Perhaps the most important discovery of the past 25 years has been the realisation that biosystematic study DO NOT LEAD to an unequivocal definition of taxonomic categories-genera, species, subspecies; they contribute to our understanding of the populations and processes by which they have changed but donot DICTATE the taxonomic decisions that have to be taken in the light of this information"
Present Scenario
The number of animal species known from the smface of the earth is far from complete, and nearly 1.75 million species are described and about 70 per cent of them come from tropical countries. The need for a holistic information on all faunal groups is of prime importance but, the number of taxonomists throughout the world has drastically declined (vanishing tribe). Similarly, the challenge of completing the explorations and inventorisation still to achieve its goal. Secondly, there is already tons of biodiversity information available on the Internet, but it is absolutely chaotic. One of the major efforts during these years is the plan based on the existing information to create a comprehensive and uniform index of all known speciestogether with linked catalogues of the species databases through Global Taxonomic Initiative. This will aim to complete and link together databases for roughly 1.75 million described species of plants and animals including microorganisms. The effort is of particular value in helping the Governments and countries which are signatories of CBD with the intention of fulfilling commitments to take stock of and conserve their biological resources.
