Module 9S2 Changes in Populations
Module Summary and Assessment
Module Summary—Section 2
To quantitatively describe changes in populations we need several tools. Formulas for population size, density, growth rate, and per capita growth rate allow us to collect the appropriate information needed to make informed decisions as wildlife managers, developers, politicians, academics, and concerned citizens. By itself, this data is not useful, unless we compare it to the normal patterns of growth observed in different species.
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Different species have evolved two distinct strategies of growth to maximize their reproductive potential and survivability (r and K selection). These patterns are indicated by specific growth curves (logistic K and exponential J). A given set of species characteristics indicates each strategy, and we can predict the course of a given population by matching it with those characteristics.
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Observed changes from the normal patterns are considered flags that indicate disruption, either from human activities, density independent factors, or density dependent factors. Human populations can be characterized by these same parameters, however human populations tend to differ from others due to our tendency to change our own environments using technology. Debate and controversy about how human growth differs from the growth patterns of other species has led to differing predictions about future human population trends.
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Module Assessment—Section 2
In addition to submitting summaries for the tutorial videos in this module, you should have also submitted the assignments listed below.
Bio30 4.9.1S2 online assignment
Bio30 4.9.2S2 online assignment