Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
CHAPTER 5 POPULATION ECOLOGY POPULATION DENSITY • Measures how crowded a population is 3 types • 1. • 2. • 3. POPULATION DYNAMICS • = number of births over time • = deaths over a period of time • Life expectancy = how long individuals in pop. are expected to live – Take a guess: life expectancy for men and women in United States • Men = • Women = POPULATION GROWTH RATE • • Growth rate= change in population size over time Depends upon the following: – Birth – – Immigration – AGE STRUCTURES What is a rate? What is birth rate? What is death rate? What are two additional factors that cause a population to increase? Decrease? What does per capita or % annual growth rate mean? CONCEPT MAP FOR POPULATION GROWTH EXPONENTIAL MODEL • • Says that populations grow rapidly after only a few generations Bacteria follow this model DRAW and LABEL THE CURVE LOGISTIC MODEL • • • Populations are limited by their environment Any factor that limits population growth is called a limiting factor Limiting factors include things like DRAW and LABEL THE CURVE 5–2 Limits to Growth Limiting Factors Density-Dependent Factors 1. Extinction 2. Competition 3. Predation 4. Parasitism and Disease C. Density-Independent Factors A. B. DENSITY DEPENDENT FACTORS – DENSITY INDEPENDENT FACTORS – EXTINCTION – Special case: Small populations COMPETITION AND PREDATION – one organism directly impacts the population growth of the other EX. Oh Deer! HUMAN POPULATION They have exploded over the last 1000 years The death rates have decreased and the birth rates have increased. This makes the overall growth rate increase. Do you think that this current human population is sustainable? Do you think that we are way past our carrying capacity and it will go down?