The word “Population Growth” has its origin from the latin words ‘Populus’ meaning people. According to ecological term; “population is group of people of the same species occupying a particular space”. Population is subdivided further into demes or local population which is group of interbreeding organism in demes; they share a common gene pool. Population density is defined as a number of individual per unit area or per unit volume of environment. When the size of the individual is uniform the density is expressed in terms of number of individuals. In case of mixed population it is expressed in biomass density. Population density is also measured as abundance of absolute number of population. Generally, in an area smaller animals are more abundant than larger animals. Crude density is the density per unit total space. For e.g., in plant species like Cassia torn individuals are found more crowded in shady patches and few in other parts of same area. Thus, density in the total area would be crude density, whereas the density value for only shady area would be ecological density. World Human Population Growth Trend
After every 12 years, the world’s population grows 15,000 each hour or 90 million per year. The rate of natural population growth is 0.5% per year in the developed countries and about 2% in a year in the developing nation. India which has 16% of the world’s total population will continue to be holding this position till 2025. Cities with more than 10 million populations are called mega cities. In 1992 there were 14 and in 2005 there were 24 megacities. The precisely statistical study of human population is called demography. It takes in account the age and sex ratio of human population. Moreover their size is also considered to make future predictions about population growth. Affects of Population Growth
i. The rapid growth of population balances the country’s political and administrative apparatus plus it imposes a variety of burdens on the...
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