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Populations. Population or not?. The monkeys in a rainforest. E. coli bacteria growing in a petri dish. Humans on Earth. The cats in my neighborhood. The trees in a forest. BioEd Online. Population. A group of organisms of the same species that live within a given area.
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Population or not? The monkeys in a rainforest
BioEd Online Population • A group of organisms of the same species that live within a given area Ostriches are nomadic, wandering in small groups. Aspen trees are quick to pioneer areas that have been disturbed by fire.
a) Dispersion • Give an example of each type
c) Growth Rate (Births + Immigrants) - (Deaths + Emigrants) Population Size
One bacterium divides in two in 20 minutes. This process continues for several days. • Sketch the population growth graph.
Exponential growth is a rapid population increase due to an abundance of resources.
Logistic growth curve (S shape) isdue to a population facing limited resources. Carrying capacity is the maximum number of individuals in a population that the environment can support
Ecological factors limit population growth • Density-dependent limiting factors are affected by the number of individuals in a given area.
Competition for food, shelter Predation Parasitism and disease Density-dependent limiting factors are affected by the number of individuals in a given area.
Unusual weather Natural disasters Human activities Density-independent limiting factors limit a population’s growth regardless of the density
Density - dependent or density – independent factor? • Tornado • independent • Food supply • dependent • Amount of rainfall • independent • Temperature • independent • Available drinking water • dependent • Spreading of a disease • dependent
Choose type I, II, or III for • Humans • Fish • Lizards • Birds • Insects • Lions • Squirrels • Plants
Most Populated Cities (1/6/2007) http://www.citymayors.com/statistics/largest-cities-population-125.html
http://www-popexpo.ined.fr/eMain.html hhttp://www-popexpo.ined.fr/eMain.htmlttp:/www-popexpo.ined.fr/eMain.html
Doubling Time • The amount of time needed for a population to double • Doubling time (in years) = 70 annual percent growth rate • The world’s annual growth rate is about 1.75%. What is the current doubling time? • 40 years
What is an ecological footprint? • The demands a person places on the environment in terms of land, water, food, waste, fibers, etc. • Go to www.myfootprint.org and take the quiz. Bring in your results.
"It's up to us to make a global effort to limit population growth - or we can wait until the environment does it for us."
http://www-popexpo.ined.fr/eMain.html Sources cited • http://www.biology.iupui.edu/biocourses/N100H/ch39pop.html • http://ublib.buffalo.edu/libraries/projects/cases/squirrel_monkey/monkey.gif • http://office.microsoft.com/clipart/basket.aspx • http://www.frame37gallery.com/gfo • http://www-popexpo.ined.fr/eMain.htmlrest22.htm • http://www.prb.org/Content/NavigationMenu/PRB/AboutPRB/Population_Today1/may99_pt.pdf