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Vidhata was ecstatic. His curiosity was increasing continuously. The earth was changing conspicuously. Land mass increased with corresponding shrinkage of water bodies. Paralleling complexity, diversity and variations increased in the biosphere As already stated a section of the organisms contained photosensitive particles. They produced organic matter by the process of photosynthesis and other accompanying synthetic metabolic functions. They are classified as producers. The other section of organisms receives organic matter from them and is classified as consumers. They are classified as consumers of the first order. Organisms receiving food from them are consumers of the second order while the consumers of the third order receive food from consumers as well as producers. Consumers of the first order are herbivores, while the second order is named carnivores while those of the third order are omnivores. Microbes constitute another class in the ecosystem, This group is called decomposer. The decomposers turn the dead and decomposing organic matter to simpler forms so that they now become constituents of abiotic environs and available to the producers.Thus a food chain functions between the biotic and abiotic components of the ecosystem.
Vidhata made another significant observation. An organism grows with time, reproduces and then decays and dies. Vidhata observed that several methods of reproduction emerged when living organisms were still limited to watery environs. In one instance an independent cell would germinate to give rise to a new individual, in another instance two such cells would fuse to form a zygote, which germinates to give rise to a new individual of a new generation. Prior to entering into reproductive mode a cell would become metabolically sluggish. The generation raised from the germination of zygotic cell is resurgent and stronger. The wear and tear of the parental generation is more than compensated in the generation raised from the zygote. Organisms tide over the unfavourable conditions by slowing down their metabolism and resuming on return of favourable conditions. That is known as rejuvenation of sorts. Vidhata observed the stimulating influence of unfavourable and adverse environment.
Variations in the method of reproduction kept on increasing with time. The two conjugating cells (gametes) are equal in some cases, and unequal in others. The larger gamete in the later case is comparatively sluggish and less mobile. The relatively smaller gamete is more mobile and this difference facilitates fusion resulting in the formation of zygote. Thus sexual method of reproduction came into being. With passage of time living organisms inhabitated land mass. By that time sexual means of reproduction was quite entrenched. It is more efficient, economical and promising with unending possibilities to cope with the rapidly changing environment. The new born is assured of protection and assured supply of resources in the early tender stages.
Reproduction leads to multiplication in number of organisms. Organisms at every level compete for the resources which are limited.. That leads to tension among the biotic components of the ecosystem. Resources are put to strain as a consequence. In the event of distress and tension, increase in variations among organisms at each level is helpful for adaptation. Those successful in turning the resources towards themselves, survive at the cost of others, Survivors are only those who are capable of putting up with tension at each step. Others perish by becoming extinct. So the next generations have such organisms, which were scarcely discernible in the previous generations. Thus, new species evolve by the process of EVOLUTION. Variations keep on increasing in the continuing journey of the biosphere. New species continue to appear along with the extinction of many existing species.
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