1. Bellringer Thu, 11/03 1.Name 3 factors you think led to explosive human population growth in the last 100 years. THINK!!! YOU KNOW IT! 2.Name 3 limiting factors that might limit population growth (now, in the past or in the future)? THINK!!! YOU KNOW THIS! Reminders: LAB FEE NOW! HW #5 due Fri!

2. Population Video

3. What are some factors you think led to explosive human population growth? THINK! What are some factors that might limit population growth? In the video, what does the glass of water represent? Do you think the earth is overpopulated?

4. What do patterns of population growth look like?

5. When you work more, you get paid more, but income growth is called linear $$$ hours worked 12345 5 10 15 20 25 pay: $5/hour 8 hours = $40

6. But what if your income growth looked like this? How much money would you make after 8 hours? 50 100 150 200 250 300 12345 starting pay: $2/hour $$$ hours worked 8 hours = $256!!! 678

7. This is called exponential growth Biologists also call this a “J” curve population size time Copy this in your notes! does the shape of this graph look familiar?

8. Definition to write down... exponential growth: as a population gets larger, the rate of increase gets larger (a “J” curve) Populations grow exponentially!!!! BUT- can this go on forever?

9. What does exponential growth look like? first generation second generation third generation, and so on... birth rate = 2 (2 births per person) any birth rate greater than 1.0 will result in exponential growth

10. So populations grow exponentially under “ideal” conditions... Like what? Examples? … but what really happens in nature?

11. In nature, population growth is eventually slowed down by limiting factors ? ? ?

12. limiting factor: any biotic or abiotic factor that limits population growth (YOU KNOW THIS!!!) Limiting Factors

13. What happens when population growth is controlled by limiting factors? population size time ? ? ? ? ? ? ?

14. What happens when population growth is controlled by limiting factors? population size time limiting factors population is still producing offspring carrying capacity

15. population size time Copy this in your notes! Biologists call this logistic growth (to remember: logistic and limit both begin with “L”) limiting factors population is still producing offspring carrying capacity what letter do you think biologists call this curve?

16. “S” curve (think stability) population size time limiting factors population is still producing offspring carrying capacity

17. Two more definitions for your notes logistic growth: when a population’s growth slows or stops following a period of exponential growth (an “S” curve) carrying capacity: the number of organisms (think population) that an environment can support

18. Is human population growth out of control? Directions on your desk!!! Create a graph of human population growth from 1650 to 2004 Answer analysis questions in your notebook Think back to the video and what you just learned: do you think there a carrying capacity for the human population on earth?  Question 5: Explain your answer based on your own knowledge, experience and opinions.