ENVIRONMENTAL ECOLOGY, BIODIVERSITY AND CLIMATE CHANGE BIODIVERSITY: THE BIOLOGICAL PERSPECTIVE

INTRODUCTION

             The biosphere is a global ecosystem. It includes the entire portion of the earth inhabited by life. In a boarder sense. Biospheres are any closed, self- regulating systems. The term “biosphere” was coined by geologist Eduard Suess in 1875. He defined biosphere as the place on earth’s surface where life dwells.

         The biosphere’s ecological context came from 1920, preceding the 1935 introduction of the term “ecosystems” by sir Arthur Tansley. Valdimir  I. Vernadsky defined ecology as the science of the biosphere. It is an interdisciplinary concept for integrating astronomy, geophysics, meteorology, bio geography, evolution, geology, geochemistry, hydrology and all life and earth sciences. The biosphere is a core concept with biology and ecology. Ecology provides a scientific context for evaluation environmental issues. To address environmental issues. To address environmental problems, we need to understand the interaction of organisms and their environments. The science of ecology provides that understanding. It is important to communicate the scientific complexity of environmental issues.

Ecology

       Ecology is the scientific study of the rich and varied interactions between organisms and their abiotic environment. In ecological studies, the environment encompasses both abiotic (such as water, mineral nutrients, light, temperature) and biotic factors (living organism). Interactions between organisms and their environment is a two way process in which organisms influence and are influenced by their environment.  There are many reasons to care about ecology. Our lives are enriched by the fascinating interactions between the organisms. Watching a butterfly visiting a flower and bringing about pollination is worth seeing. Beyond simple curiosity, information from ecological sciences is needed to solve many practical problems. An understanding of ecology allows us to grow food, control pests and diseases and deal with natural disasters such as flood, drought and earthquake.

BIODIVERSITY: ANIMALS

   There is enormous biological diversity!

                  There are almost 8.7 million species on this earth. This number is rapidly increasing every day. This mind boggling number makes it almost impossible to study each and every day. This mind boggling number makes it almost impossible to study each and every organism individually. Therefore, scientists felt that these organisms must be grouped in some fashion into discrete categories. This not only made their job simpler but also helped to characterize them. This was beginning of a system of classification. The categorization however cants be random e.g., if we list names or words in a telephone directory or dictionary randomly, we shall never be able to find or locate a particular telephone number or meaning of a particular word. Therefore, a uniform and universal scientific system of classification was developed for the organisms.

             A taxonomist’s job didn’t get over by merely classifying the organisms; the organisms also needed a scientific name. Since the organisms are known differently at different places and their common names are used casually, it creates confusion, e.g. a silver fish is an insect and not a fish; similarly, sea mouse is not even distantly related with a mouse. Hence, it necessitated a code of naming or nomenclature. A number of attempts were made in this direction but success came to the famous Swedish naturalist Carlus Linnaeus who developed the system of Bionomial Nomenclature in his book called Systems Naturae in 1758.   
        This distinction earned him the title of “Father of Taxonomy”.

BIODIVERISTY - ANIMALS

          According to his code of nomenclature , (“Bi” meaning “two”), the name of every living organism consists of two words – the first word, referring to generic name (name of the genus ), which is common with other related forms, and the second word is species name which is unique for a particular organism. The two together specify the name of the species e.g., Homo sapiens (Man, the wise) is the scientific name of “Modern man” where Homo is the name of the genus and sapiens is the name of species.

BIODIVERSITY -ANIMAL: CLASSIFICATION

Classification:
          Classification is possible because there are certain common features between related organisms but at the same time, they are also distinct from each other e.g., all snakes share certain common features and look more or less similar viz. absence of limbs, body covered with scales, forked tongue, etc. but at the same time a cobra can be easily differentiated from a viper or a krait.

           The original system of classification was artificial and based on few characters only. Therefore, it was rejected and since then continuous attempts have be made to improve it and make it more scientific and universally acceptable. This led to the development of the present taxonomic system proposed by R.H. whittaker and known by his name as Whittaker’s Five-Kingdom System of Classification (1969).

            Here, living organisms are divided into following five kingdoms:

(1)    Monera (prokaryotes)

(2)    Protista (a diverse kingdom consisting mostly of unicellular organisms both plants and animals)

(3)    Plantae (Plants)

(4)    Fungi and

(5)    Animalia (animals)

             However, when phylogenies were worked out on the basis of genetic data, it was found that prokaryotes we markedly different not only from eukaryotes but also from each other. This led biologists to modify the present system and adopt a Three-Domain System.

CELL BIOLOGY

PROPERTIES 

        The question, “what‘s life?” may appear quite native, because although a phenomenon called. “life” is quite obvious, at the same time it is also very complex.

      Living organisms is not merely a collection of basic atoms or molecules or elements viz. carbon, hydrogen, oxygen, nitrogen, sulphur, etc. but there are certain basic highlights or properties or characteristics which describe it.

Some of these are:

Cellular Organization: All organisms consist of one or more cells bounded by a membrane, which carry out basic activities of living organisms.

Ordered Complexity: All living things are complex but at the same time highly ordered. The cells are not  only organized but arranged in a hierarchical order which becomes more complex at each level e.g., the cells are grouped into tissues, which form organs, which in turn form organ systems and finally an organism.

Reproduction: “Life begets life”, i.e., living organisms produce their own kind and pass hereditart molecules to their offsprings. This is the most distinctive feature of living organisms.

Growth and Development: Most living organisms are multicelluar i.e., a single cell divides to form a number of cells, which increases both in size and number. Not only this they also undergo specialization e.g., they may form specialized cells viz. neurons, etc.

Regulation or Homeostasis:  All organisms maintain relatively “constant internal environment” by various mechanisms e.g. the water and salt concentration of body fluid, or blood glucose level or the degree of acidity or alkalinity are all kept at a stable or constant level.

Energy Processing: All organisms need energy, which they use for performing various kinds of work. This energy comes from the breakdown of various organic nutrients viz. carbohydrates, proteins, fats, etc. This energy is then used for carrying out various activities viz. locomotion or breathing.

Sensitivity or Response to the environment: All living organisms are sensitive to various stimuli viz. light, temperature, etc and then produce appropriate response to these stimuli of their environment e.g., plants grow towards light or we close our eyes in bright light or withdraw our hands from a hot object.

Evolutionary Adaptation: all living organisms interact with the other organisms as well as non-living environment. Both of these have a great effect on their survival. Therefore, in order to live successfully, they evolve adaptations to their environment e.g., animals living in cold environment have a thick coat of fur while those living in desert possess dry and scaly skin.