2.6 - Changes in populations
Lesson 1 - Exponential growth
- News and Riddle
- Syllabus and Website
- Paper square practical
- Making a J-curve
- Starting with just one bacteria, how many would there be after 24 hours?
- After how much time would the weight of these bacteria equal the earth?
- Why doesn’t this happen? What factors keep populations from growing infinitely?
- Making an S-curve
- Look at human population growth graph below. What do think will happen to human populations in the future?
- Billions worksheet
- Read pp. 160-163
Lesson 2 - Strategies for survival
- J vs. S curve
- Carrying capacity
- Environmental resistance
- Boom and crash
- Density dependent vs. Independent factors
- Internal vs. External factors
Go over billions homework
Bacteria vs. Humans discussion
- Last class, we looked at how bacterial and human populations can grow in a very similar way. For both bacteria and humans, make a separate graph showing what percentage of the population would be alive as individual’s age.
- Why are these so different even though our graphs of growth are so similar?
- What strategies do bacteria and humans employ to survive? How are they similar and how are they different? What are the strengths and weaknesses of both?
- Which strategy works better when near the carrying capacity and why?
- Complete panther activity
- How well does the concept of carrying capacity apply to human populations? Malthus predicted a K, and was completely wrong. Over time, does it apply to humans in cities, countries, continents, and the whole world?
- In what ways could humans increase our carrying capacity?
- Read pp. 163-165
- Complete "Test yourself" questions on page 164 (referring to graph on 165)
- Bring in two pictures of you to share: one as a baby and one today!
Lesson 3 - Succession
- Survivorship curves
- r vs. K strategies
- Share your baby and present photos!
- What do you notice about the two photographs? What has changed?
- How do you know if a change is happening?
- What might your face look like ‘down the line?’ What factors might affect the way you eventually look?
- Watch this TED talk: www.ted.com/talks/daniel_pauly_the_ocean_s_shifting_baseline/
- Complete this worksheet watching the three videos: 1 and 2 and 3.
- During succession, which stages provide optimal conditions for r and K type organisms?
- Read through the activities and pass the quiz: http://www.mrphome.net/mrp/succession.swf
- Watch: http://wps.prenhall.com/wps/media/objects/2688/2752944/Web_Tutorials/23_A02.swf (3 minutes)
- Complete the following worksheet in pairs:
- Read pp. 265-271
- Watch: https://www.youtube.com/watch?v=jZKIHe2LDP8
Lesson 4 - Review
- Primary succession
- Secondary succession
- Climax communities
- Factors affecting climax communities
- Gross and net productivity
- Succession and zonation
- Arrested and deflected succession
- Begin studying for quiz!
- Read pp. 272-275
- Complete "To do" on page 275.
2.6 review lecture
- Study for quiz!