Biology 1001A Lecture Notes - Demographic Transition, Interspecific Competition, Paramecium
24 Aug 2013
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Document Summary
Human population size (worldwide) is still increasing because we have succeeded in increasing our carrying capacity. E. g. while some continents are projected to increase in population size, some are projected to decrease, or stay the same. E. g. growth rate in united states is zero; growth rate in mexico is rapid; all due to age structure. Increasing n (population), but decreasing r (growth rate): Globally, r = 0. 011 or 1. 1 % (per person per year) Population sizes won"t decrease until r becomes negative. Over time, human societies get wealthier and throughout the industrial age, human birth rates and death rates are subject to tremendous variation. The interactions within a population and between other populations are sometimes more significant than population size. Community: a set of assemblage of populations that interact with each other. Some species are limited by a single critical factor (e. g. temperature, water abundance, daylight, etc. ) Role-based ecological niche: what an organism does in their environment or society.
