AP Biology Population Ecology Chapter 52 Modified from: Kim Foglia, Explore Biology

AP Biology Changes to population size  Adding & removing individuals from a population  birth  death  immigration  emigration

AP Biology Growth rate  Exponential growth  characteristic of a population without limiting factors  ex. introduced to a new environment African elephant protected from hunting Whooping crane coming back from near extinction

AP Biology Carrying capacity  Can populations continue to grow exponentially?  of course NOT!  what sets limit?  resources, predators, parasites  Carrying Capacity (K)  maximum population size that environment can support with no degradation of habitat  not fixed; varies with changes in resources

AP Biology Model of growth Decrease in rate of growth as reach carrying capacity

AP Biology Different life strategies  K-selection  r-selection K-selection r-selection mortality constant

AP Biology Reproductive strategies  K-strategy  have few offspring & invest a lot of energy in raising them to reproductive age  primates  coconut  r-strategy  have many offspring & invest little in their survival  insects  dandelion & other weeds

AP Biology Predator – prey interactions  Population cycles

AP Biology Age structure  Relative number of individuals of each age What do the data imply about population growth in these countries?

AP Biology Human population What factors have contributed to this exponential growth pattern? 1650  500 million 2005  6 billion Is the human population reaching carrying capacity?