BIO 311D 2nd Edition Lecture 35 Outline of Last Lecture I Introduction to population ecology II Population growth models III Population dispersion survivorship mortality Outline of Current Lecture I Measuring population growth II Population growth models III Human population growth IV Index Card Questions Current Lecture I Measuring population growth A Population dynamics per capita rate of increase 1 N T b i d e 2 r per capita rate of increase in number of individuals can be negative a N T bN dN b r b d B In 2006 the United States had a population of about 300 million people If there were 14 births and 8 deaths per 1 000 people what was the country s net population growth that year 300 million 1000 multiply by 6 C You are studying a population of beetles of size 3000 During a one month period you record 400 births and 150 deaths in this population Estimate b d and r for that month and project the population size after a second month R 08 400 150 3000 3250 8 of 3250 II Population Growth Models A J Shaped exponential growth unrestricted growth 1 Elephant in Kenya elephant was protected and population went straight up 2 r growth rate greater r accelerated growth 3 Point of maximum growth as far up as you can go B S Shaped logistic growth restricted growth 1 Carrying capacity K is the maximum population size that a particular environment can support 2 The rate accelerates point of maximum growth the rate slows down C In the following graph which of the expressions of the exponential growth equation should be increased for curve 1 to become more like curve 2 1 N T make it steeper 2 D move to the right 3 B move to the left 4 b d D C E 4 8 barely maximum not enough people for mating E What causes these population changes Figs 52 18 52 19 1 Mortality factors a Density dependent Predation b Density independent 2 Which of the following statements is an example of a density independent effect a The number of nests in an area is limited to 70 b The incidence of malaria increases as population increases III c A drought kills all the seedlings in an area d Large aggregations of guppies attract predators Human Population Growth A What has affected human population growth in the past In the present 1 Industrial revolution agriculture medicine 2 Mortality rates has decreased due to medical care 3 Life expectancy rates increasing depending where you are B Age Pyramids 1 Rapid growth more kids fewer older group 2 Slow growth baby boomers bulges of greater birth rate 3 Decrease C Health rate Medical care water can cause change in population rate
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