S-Shaped Curve – population initially shows exponential growth, thenPopulation Growth the population numbers level out as it approaches K Carrying Capacity (K) – The largest population a particular environment can support sustainable (long- term) assuming there are no changes in that environment.
Exponential Population GrowthThe larger the population gets the fasterit grows.Population of bacteria = 2nn = the number of times the bacteria havedoubled in size, occurs every 30 minutesIn 24 hours the bacteria would double 48times (n = 48)Therefore, the population of bacteria after24 hours of growth is:248 = 281,474,976,710,656
How Populations are Measured 3. Doubling Times: number of years it will take a population to double, assuming the current growth rates remain constant Rule of 70: a means of calculating doubling times, 70 divided by the current annual growth rate. population doubling time = 70 ÷ annual rate of growth This rule applies to things at exponential growth (e.g., human population growth)In finance we have the rule of 72 that says: If I invest $100 at 9% interest peryear then I can divide 72 by 9 (72/9 = 8), and this will tell me that in 8 years I willhave $200.
At 1.3% population growth, humanpopulation will double in 55 years!
NOVA – Pregnancy Obstetric Fistula and Child Birthin Ethiopia (Chapter 4, beginning of 5, 6)“A Walk to Beautiful”http://www.pbs.org/video/video/980049841/chapter/1/search/Africa%20PovertyOver 9,000 woman and girls develop fistula eachyear in Ethiopia alone
NOVA – Child Birth in Developedversus Undeveloped Country:http://www.pbs.org/wgbh/nova/beautiful/women.html
“Vampires” among the plague victims excavated inItalian Plague (The Black Death) Graves from 1300s– March, 2009.http://news.nationalgeographic.com/news/2007/08/photogalleries/massgrave-pictures/photo4.html
Meadows, Dennis et al., The Limits to Growth, Potomac Associates, Washington DC,1972; Meadows, Donella et al., Beyond the Limits, Earthscan Publications, 1992.