Population Growth Potential Is Related to Life History

Population Growth Potential Is Related to Life History -...

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Population Growth Potential Is Related to Life History The age within it's individual life cycle at which an organism reproduces affects the rate of population increase. Life history refers to the age of sexual maturity, age of death, and other events in that individual's lifetime that influence reproductive traits. Some organisms grow fast, reproduce quickly, and have abundant offspring each reproductive cycle. Other organisms grow slowly, reproduce at a late age, and have few offspring per cycle. Most organisms are intermediate to these two extremes. Age structure refers to the relative proportion of individuals in each age group of a population. Populations with more individuals aged at or before reproductive age have a pyramid-shaped age structure graph, and can expand rapidly as the young mature
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and breed. Stable populations have relatively the same numbers in each of the age
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Unformatted text preview: classes. Human populations are in a growth phase. Since evolving about 200,000 years ago, our species has proliferated and spread over the Earth. Beginning in 1650, the slow population increases of our species exponentially increased. New technologies for hunting and farming have enabled this expansion. It took 1800 years to reach a total population of 1 billion, but only 130 years to reach 2 billion, and a mere 45 years to reach 4 billion. Despite technological advances, factors influencing population growth will eventually limit expansion of human population. These will involve limitation of physical and biological resources as world population increased to over six billion in 1999. The 1987 population was estimated at a puny 5 billion....
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Population Growth Potential Is Related to Life History -...

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