Checkpoint: Ecology and Population Growth
University of Phoenix
SCI 230 Introduction to Life Science
September 30, 2010
Ecology and Population Growth
The current estimate of the worldwide human population at this moment is approximately 6,872,164,233. Every minute, the world's human population increases by 176 people. At the beginning of this century, earth's human population already surpassed 6 billion; at the end of the century, it could reach 12 billion (Aliette, 2001). The population changes dynamically due to a number of factors: birth rates, death rates, age, fertility rates, natality, mortality, etc. The population growth rate prediction is established by a few factors: birth and death rates. The formula for calculating the rate of natural increase is r = (b-d); r is population growth rate, b is birth rate, and d is death rate. Thus, population growth is directly related to: 1) current population - the number of people today has implications for future population, 2) birth rate - this number is usually reported in number of births per 1,000 people per year and combined with the death rate influences the growth of population, and 3) death rate - this number is usually reported in number of deaths per 1,000 people per year and combined with birth rate influences the growth of population (Wenner, 2009). Exponential growth can also be used to model population growth at any time. The formula for calculating exponential growth is (dN/dt) = rN: 1) r is the rate of natural increase and is usually expressed as a percentage (birth rate - death rate), 2) t a stated interval of time, and 3) n is the number of individuals in the population at a given instant (Wenner, 2009). Human growth continues to impact our current ecosystem as they constantly change the appearance of earth. Many of our foods come from the land and sea, but it will not be an infinite resource with the world population increasing approximately 2% annually. As our...