Abstract

An appreciation of biodiversity demands a knowledge of its abundance curve which, mass global extinctions notwithstanding, is upwardly moving during past 600 million years. It is within this historical context that we can perceive that the human induced species extinction is undermining the very base of the human sustenance. Education based on the concept of biodiversity as a function of global prehistorical phenomena can make us aware of the web that connects the existence of the human species with the rest of the biota and nature. In this essay we suggest that courses on biodiversity, nature conservancy and related activism are imperative for our education curriculum, and should be introduced at the school level. Such courses should include an essential knowledge of the evolution of species, atmosphere
and land formations.

1. Introduction

Imagine yourself stepping into the "haor" wetland basin of Sylhet or Mymensingh only a few thousand years ago. Your eyes would be greeted with tall reeds in vast areas of swamp silhouetted by forests of hijal and koroch. And then you would see crocodiles, otters, wild buffalos, swamp deers and rhinoceros roaming through the marshland. As you walk towards higher grounds you meet elephants, gaurs, Sambar deers, hog deers, and wild boars sharing the forests and grasslands with tigers and leopards. Now you look back towards the water only to be amazed with the fluttering noise of numerous species of birds including migrant ducks and herons, egrets, storks, ibises, whistling-ducks, comb ducks, pygmy geese and Sarus cranes.

Now fast forward to today. The swamp forests, scrub jungle, bamboo thickets, and dense stands of reeds have almost entirely disappeared. Erosion is making the surrounding villages flood prone. Most of the large mammal species have all but gone. Vast areas of the seasonally flooded plains have been converted to rice monoculture and all higher lands are used for permanent human settlement. The entire ecosystem is almost destroyed. Still villagers rely on these wetlands for biomass fuel, building material, fodder, and food. But these potentially renewable resources are becoming more scarce. The "haor" environment degradation
and biodiversity loss is vividly described by the Wetland Resources study (Bennett et al. 1998). We are citing from this report because of its immediate visual effects and the connection it establishes with our vanished biowealth. These recreations of prehistory evoke a sense of loss that helps us in assessing the role of biodiversity
in our lives.

The entire concept of biodiversity is quite new in Bangladesh. For most people, even if the restoration of the environment makes sense through measures such as pollution abatement, the loss of biodiversity represents an elusive and unexplained phenomenon. In a developing country like Bangladesh, the biodiversity and nature conservancy programmes remain more delicate than general environmental initiatives. Historically, the population considers wildlife a threat and with the advent of
crop monocultures and pharmaceutical medicines, give much less importance to diverse crop cultures and traditional medicinal plants. Even among some educated social activists, misconceptions, such as biodiversity studies give more priority to animal existence than human, reign. This is our believe that any basic understanding of this problem requires the introduction of mass education on diversity and conservancy with special emphasis on the natural progression of biodiversity through
prehistory.

2 What is biodiversity?

The definition of biodiversity is based on the diversification of the biological species. In the taxonomic order of living things, species is the most basic unit. The measure of biodiversity not only includes the abundance of species, but also the diversification of higher categories of classifications: Species -> Genus -> Family -> Order -> Class -> Phylum -> Kingdom. At the very top of this classification 5 kingdoms contain 89 phyla. The living kingdoms are comprised of i) Plantae
- multicellular plants, ii) Fungi - mushrooms, fungi, etc, iii) Animalia - sponges to mammals, iv) Protista - single celled organisms like protozoa, v) Monera - single celled organisms like bacteria.

Biologists also describe biodiversity in terms of biological organizations which take into account the behaviour of different species within a large ecosystem and the genes that make up individual species. An example of it could be the biota within the Sundarban ecosystem. Here a few hundred tigers share about 10,000 square kilometers of forest within the largest delta complex of the world with at least 35 species of reptiles, 40 species of mammals and over 270 species of birds.
Over 334 plant species thrive in this delta which is fringed by the largest mangrove swamp in the world. The mangroves include 27 different species. One can find that there are compositional, structural and functional attributes of biodiversity operating at different hierarchical scales and linked by biological processes (Noss 1990) in such a complex ecosystem. This broad approach towards diversity can include many wider issues of ecology such as gene flow, species turnover, species
packing, minimum viable populations, predation, disturbance, etc. (Maddock and Plessis 1999).

Some workers in this field have described the biodiversity as a multilevel process of conditions and impacts which include the human decision making process (Kamppinen and Walls 1999). They suggest to break biodiversity into two constituents, the core biodiversity and the overall biodiversity. The core is understood as a biological entity, and the overall biodiversity includes the relevant conditions and impacts in the social economic realms.

3 How much biodiversity is here?

To date approximately 1.4 million living species of all kinds of organisms have been catalogued (Parker 1982). Of these a little more than a million belong to the animalia kingdom and approximately a quarter of a million to the plant kingdom. Among animals about 750,000 are insects and 41,000 are vertebrates. The rest, approximately 130,500 species belong to the Fungi, Protozoa and Monera kingdoms. But most biologists agree that not all species have been catalogued. According to E.O. Wilson, multitude number of species remain to be discovered in the bacteria, fungi and other poorly studied groups and the absolute number of species might be somewhere between 10 and 100 million (Wilson 1992).

Another way of defining the biodiversity is based on the nucleotide sequence or the letters of the genetic code. A total of 10^{17} nucleotide pairs would specify the full genetic diversity among all species (Wilson 1992).

4 How fast is biodiversity declining?

The dataset on the rate of decline of biodiversity due to human intervention is insufficient. Biologists have applied the area-species curves of the island systems to estimate this rate. This curve provides a quantative relationship between the area of islands and the number of species that can persist on the islands. It has been seen that the smaller the island the higher is the decay constant and the extinction rate (Diamond 1984, Terborgh 1974). However, the species abundance go through
a series of equilibrium points where reduced biodiversity temporarily remains constant. Using the area-species relationship, Simberoff (1984) predicted 12% loss of the 704 bird-species in the Amazon basin and 15% of the 52,000 plant species in South and Central America within the next 100 years. In the rain forest, due to clear cutting of trees, the number of species doomed each year is 27,000 which translates to 3 per hour. The global annual species reduction is possibly 17,500
species per year. If the total number of species is about 10 million, then the loss is roughly one out of every thousand species per year (Wilson 1992).

5 Is this decline unnatural?

Approximately 540 million years ago, the animal species diversity increased significantly. This is known as the Cambrian explosion. Since then the biological diversity has increased slowly over time, with occasional setbacks through mass global extinctions. The five extinctions happened during the ends of the Ordovician (440 million years ago), Devonian (350 million years ago), Permian (250 million years ago), Triassic (210 million years) and Cretaceous (65 million years) periods. The
exact reasons for these extinctions are still debated, but scientists have found ample evidence of volcanism and extra-terrestrial impacts such as asteroid cratering, which could initiate such mass-scale extinctions,
during those time periods. The most serious of these, the Permian extinction eliminated 52% of the marine animal families and an estimated 77 to 96% of all marine species. If these estimates are true, global life forms had a very close brush with total destruction (Raup 1988). It took millions of years for the diversity to attain its former abundance. Since then the biodiversity has increased due to the creation of the aerobic environment and the fragmentation of the land masses.

But now humanity has initiated the sixth great extinction episode. A large number of existing species will be extinct within a single generation. This rate of extinction is quite unnatural. Based on the Paleozoic and Mesozoic marine faunas (590 to 65 million years ago), the normal background extinction rate is about one species per one million species a year (Wilson 1988). The human activity has increased this rate by more than 1,000 to 10,000 times. This rate is faster than the rates during the five global mass extinctions in the past. Unfortunately, as paleontology shows, the recovery takes millions of years in an undisturbed world. Even if the future generations adopt the necessary conservancy efforts, in a human inhabited earth the recovery will take tens of millions of years. Surely, such time range
is not meaningful for the humanity.

6 What is the value of biodiversity?

Economists have tried to assign a commodity value to a species if it can be made into a product that can be bought or sold in the market place. A species also might have an amenity value if its existence improves our lives in some nonmaterial way, e.g., experiencing the sight of a deer or a great banyan tree. Some assign a moral value to the existence of species - they are valuable in themselves, i.e., their existence value is not dependent on any human usage (Norton 1988). At present, we do not have sufficient data to calculate the commodity value of most of the species. Many economists calculate an option value for species of unknown worth, i.e., the value we should place on the possibility that a future discovery will make use of a species that we currently think useless.

Let us look at just one aspect of the commodity value of the plant diversity. About 120 pure chemical substances extracted from higher plants are used in medicine throughout the world. To give you a few examples of plant extracts used in traditional and modern medicine we might mention Digitalis Purpurea or Common Foxglove from which Digitoxin is obtained as a cardiotonic or the widely used analgesic Codeine extracted from opium poppy (Papaver Somniferum) which has
been traditinally used as an analgesic or sedative for centuries. We should also mention valuable trees such as Neem which has found multiple health and medicinal uses in South Asia throughout centuries (the recent war of patent rights on Neem extracts is another dimension of global biodiversity policy decision that needs to be resolved).

Many researchers believe that they can get new drugs faster and cheaper by computer modeling of molecular structures. Hence, for them the extinction of useful medicinal plants would not create problems. For this reason some conservationists have warned against judging biodiversity solely on the basis of economic justification. However, higher plants are chemical factories that are capable of synthesizing unlimited numbers of highly complex substances whose structures could escape the modeling of synthetic chemistry (Wilson 1992). Considering that many of these unique gene sources may be lost forever through extinction and that plants have a great potential for producing new drugs of great benefit, immediate action should be taken to preserve biodiversity.

It is a fact that species, habitats and ecosystems that do not have economic value are often the first ones to vanish. The continued existence of most species will depend upon their capacity to find a role in the societal asset of portfolio (Swanson 1999). Whenever a given species is not expressly selected within this portfolio, it is subjected to the general forces of disinvestement that lead to its decline. Hence, it is imperative that the population is motivated to find non-economical
values of biodiversity and cherish it.

7 Some global initiatives

The Convention on Biological Diversity (CBD) was signed by over 150 governments at the 1992 Earth Summit in Rio de Janeiro and became effective as an international law in December 1993. It is the first international agreement committing governments to comprehensive protection of the Earth's biological resources. The CBD has three overall goals - the conservation of biological diversity, the sustainable use of its components, and the fair and equitable distribution of benefits
derived from "genetic resources." By signing the CBD the participatory governments agreed to carry out various conservation measures including the creation of national plans for the protection of biodiversity. One of the most evident outcomes of this convention is that it generated wide interest in biodiversity at national levels.

The primary tactic of the global conservancy measures is to locate the threatened ecosystems and protect them. This ensures not only the most charismatic species but the representatives of thousands of lesser known species that live with them and are also threatened. Currently environmentalists are trying to expand reserves from 4.3% to 10% of the land surface. One of the promising means to attain this goal is by debt-for-nature swaps. In this programme, organizations such as the Conservation International, the Nature Conservancy, and the World Wildlife Fund raise funds to purchase a portion of a country's commercial debt at a discount. The debts are then exchanged in local currency or bonds set at a favourable rate. The enlarged equity is used to promote conservation, especially by the purchase of land, environmental education and the improvement of land management. This program has been particularly susccessful in many countries of South and Central America.

The World Bank, the United Nations Environmental Program and the United Nation's Development Program initiated the Global Environment Facility which is committed to set up national parks, promote sustainable forestry and establish conservation trust funds in developing countries.

8 Risk assessment and education

Reyers et al. (1998) have constructed a national biodiversity risk management index (NABRAI) to identify countries with critical conservation concern. The index is based on three parameters - a stock value refering to a country's biological richness or endemism, the extent of undisturbed habitat, etc; a pressure value defining the threats to biodiversity and a response variable refering to the conservation effort. Bangladesh is the 10th most threatened country in the NABRAI ranking. The first
9 countries are Burundi, Swaziland, Rwanda, Laos, El Salvador, Haiti, Sierra Leone, Cambodia and Jamaica. The global NABRAI rank for India is 78. The authors contend that the combination of the multivariate analyses and the interpretation of NABRAI values allows for prioritization of biodiversity risk among the global community and can thus serve as an indicator of current priorities for policy makers. However, because Bangladesh is not a megadiversity nation Reyers et al. do
not list Bangladesh in their priority list of countries of immediate concern. This makes conservation efforts difficult in Bangladesh because most of the times the global attention is enjoyed only by biodiversity-rich countries.

Unlike many other environmental problems, technology fixes are not likely to provide solutions to most biodiversity related problems. There is a specific demand for new approaches and research activities, which appreciate different traditions and methodologies, as well as traditional knowledge (Walls et al. 1999). This makes the participation of the local community in the management of conservation programs essential. However, before embarking on such ventures several factors should be taken into account. In Bangladesh, population over-density has always resulted in a human-animal conflict and during most of history, wildlife has been considered a threat. Even many educated social workers harbour sceptical attitudes towards biodiversity studies and assumes international agencies are more interested in conserving migrant ducks than humans. In another front, with the advent of crop monocultures and widespread use of pharmaceutical medicines, the importance
of diverse crop cultures and traditional medicinal plants are on the decline. People understand the paramount importance of the environment restoration in terms of air, water or arsenic pollution mitigation, but have only a very vague notion of why plant or animal species abundance can be important. Even in places where the  concept of the conservation is supported among the rural population, the lack of alternatives force people to exploit the nature destructively (Badola 1998) . Forestry
agencies are often totally unable to manage vast tracts of land. They remove local incentives for conservation and antagonize the local  population (Wells 1998, Badola 1998). Hence any attempt to implement the community environment initiative should give priority not only to the education of the local community but also of the authority. Where should then the biodiversity education begin?

Although the term "biodiversity" means little to most rural communities, such communities often have extensive experience with a variety of sustainable manipulation and use systems that are compatible with biodiversity conservation (Alcorn 1993). However, rapid urbanization and land transformation are decoupling these communities from this experience within the span of only one generation. It is important to document these links before they completely disappear. But we should
also understand that non-economic values, emotion and motivation are potentially powerful forces to be unleashed for conservation (Goodwin 1999) and a curriculum should take into account this understanding the human dimension of natural resource management.

It is our belief that if we were familiar with the prehistoric progression of evolutionary biodiversity, we could find the place of humans among the species. We would also see that the emergence of the Homo Sapiens has occurred at the peak of biodiversity abundance. Since this emergence, appropriate crop, fruit, fish and animal diversity has sustained humanity for tens of thousand of years. It is within this historical context (as outlined in this paper) that we can perceive that the human induced
species extinction is undermining the very base of human sustenance. This awareness should make the very base of the biodiversity education. These are the motivations that should be captured by the new education. We suggest introducing biodiversity curriculum in the high school, college and university levels. In the high school level this can be a part of the biology curriculum or a completely different subject. The major focus of this subject at higher levels will be, besides
the core biological diversity, the study of human impacts on biodiversity, with emphasis on management processes that prevent species extinctions and repair anthropogenic damage to ecosystems. A section of the core biodiversity study will highlight the progression of the biodiversity abundance curve as a function of the creation of the oxygen rich environment and land fragmentation.

We end this article with one of the most widely used quotes in environment circles (Rodes and Odell 1992). The Senegalese conservationist Baba Dioum has said, "In the end, we will conserve only what we love, we will love what we understand, we will understand only what we are taught." There lies the great truth about the human behaviour. We can say the better we know about ecosystems and their inner working, the less likely we are going to destroy it.
 

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