BIOL 1106 Lecture 20: Lesson 20 Notes Ecology of Individuals and Populations

Populations (Ecology)

•What’s the difference between a cohort and static life table and what are the difficulties with each? Be able to interpret data in a life table.

• Be able to draw or interpret survivorship curves for different populations. What are the differences between the three types?

• Why does population age structure matter?

• What happened to Pablo Escobar’s hippos? What are some possible consequences? What might happen in the future?

• What are exponential and geometric growth?

• Be able to graph population size over time for a given growth rate (like figure 10.11).

• What’s the difference between density dependent and density independent factors to limit growth? Give examples. Which one regulates population size? Why?

• What is logistic growth? Explain how the growth rate changes at different population sizes. Be able to compare logistic and exponential growth.

• What are the four factors that affect population size over time?

• What are population cycles? What are some of the factors that drive them?

• What is delayed density dependence and why does delayed density dependence cause populations to fluctuate? What factors affect these fluctuations? Be able to draw typical population fluctuation figures like fig. 11.10.

• What’s the difference between stabilizing and destabilizing feedbacks? How do delayed feedbacks affect a stabilizing feedback?

• How does population size affect the likelihood of extinction?

• What is the Allee effect? How does it affect growth rate at different population densities? Draw a figure illustrating this.

1.What is an ecological footprint? What is the greatestcontribution that you make to your footprint? How could you reduceit?

2. Are humans a keystone species? Support your answer.

3. Why does community connectedness matter?

4. Why does community change matter?

5. What kind of environmental features favor pioneer species,what kind favor climax/late succession species? What kinds ofadaptations favor pioneer species, and what kinds favor climaxspecies?

5. What do we mean when we say that landscapes are stable?

6. What would a community ecologist be able to learn from the USCensus?

7. What does evolution have to do with community ecology?

8. What role does disturbance play in ecology? Giveexamples.

9. You will be expected to be able to calculate species richnessand determine evenness and species diversity indices.

10. You will be expected to make a connection between carryingcapacity, population growth, and community succession in NewJersey.

11. What are the factors that can or could influence thecarrying capacity of NJ?

12. Rank the following three factors in terms of their impact onhuman carrying capacity: space availability, food availability,money availability.

13. Why are some invasive species more successful (i.e. havegreater fitness) in their introduced environment compared to theirnative environment?

14. What is global change about and how do our actions affectit? How is NJ going to be affected by global change?

15. Why, if it is summer in the southern hemisphere and winterin the northern hemisphere, do we see an overall increase in globalCO2 concentrations?

16. What is a dead zone and how is it created? What humanactivity (ies) help create a dead zone?

17. How would a fire that burns most of a forest affect theenergy, water, nutrient, and carbon cycles?

18. What are ecosystem services? Give an example of two.

19. Show how the energy and carbon cycles are inter-related.Explain what is happening in your diagram.

20. You need to be able to explain why nitrogen is important andwhy too much nitrogen is bad.

21. Which gas is more important for global warming:CO₂ or methane? Why?

22. What are the major carbon sinks and sources on earth?

23. What evidence do we have that CO2 concentration of theatmosphere has increased in the last 200 years and what evidence dowe have that that increase is due to human activity?

24. What is happening to our oceans in response to the increasein CO2 in the atmosphere. Be complete, there is more than one partto this answer.

25. How do we know that global warming is and will have animpact on populations, communities, and ecosystems?

26. Given what we know about Japanese knotweed, global change,and human activity, explain the interactions and consequences ofJapanese knotweed invasion on our water supply. You need toinclude, the physiology of the plant, the population ecology of theplant, the water cycle (ecosystems), and global change.

27. Regional climate change models predict that this area willget warmer and receive more rainfall. They also predict thatagriculture (i.e. growing plants) will suffer. Explain why. Becomplete in your answer. There are several factors at workhere.

28. Why are sea-levels increasing globally? Give a detailedanswer. What are some likely consequences going to be (other thanlosing land).

PLEASE ANSWER IN PARAGRAPH FORM CORRECTLY. I appreciate it.

1. A) Describe what SexualSelection is and B) explain how it differs fromNatural Selection

2. Research a behavior in an animal andA) explain the ultimate causes of that behaviorand B) list the proximate causes of it.

3. “The southern gastric broodingfrog was discovered in 1972 and properly described in 1981. Intenseinterest followed and in the same year it had disappeared in thewild, shortly followed by the last captive specimen's death in1983. The interest was primarily due to the frog's unusualreproductive method. The female swallows her eggs and turns herstomach into a womb, vomiting up her young when they are grown. Theloss of her stomach means she doesn't eat while they develop, andher new womb bloats so much it causes her lungs to collapse(meaning she has to breathe through her skin). On the other handanother species of frog, the Túngara frog, lay their eggs in a pondand leaves them to develop on their own without any parental care”(www.facebook.com/evolutionarybiology - like). A)Compare the gastric brooding frog and the Túngara in terms of howthey balance the trade-off of quality vs. quantity of offspring(are they each K-selected or r-selected?). B) Whatother life-history traits (include: life span, number of offspringproduced, age at reproduction, reproductive events per lifetime) doyou expect to find differences between gastric brooding frog or theTúngara frog? Explain.

4. A) Explain why one can argue that humanswere K-selected species before the industrial revolution and now inmodern times see to be r-selected (in your explanation include theterms: carrying capacity, rate of population growth).B) However, in developed countries, the number ofoffspring produced per couple is decreasing every year, the age offirst time mothers in increasing (they are older when they havetheir first baby) and the cost of investment per offspring isincreasing (for example college tuition!). Explain what effectwould that have in the model of population growth in developedcountries (do you expect them to be more K-selected or r-selected?)Make sure to support your argument. C)Can human population increase forever? (use the terms: carryingcapacity, population growth, density-dependent anddensity-independent factors).

5. Study the figure below (published in Kwanoet al. 2002). The x-axis of the figure shows different locations atdifferent altitudes, with altitude decreasing from left to right(W. Java has the highest altitude, W. Mindanao has the lowest). They-axis represents the range of body length for beetles found ateach location. Two species of closely related rhinoceros beetlesinhabit Southeast Asia: Chalcosoma caucasus andChalcosoma atlas. One species, C. atlas (whiteboxes in the figure), is more common in low altitude, while C.caucasus (filled boxes in the figure) is more common in higheraltitudes. However, they overlap at intermediate altitude (fromLampung to E. Thailand). The graph shows the body length of eachspecies in allopatric and sympatric locations. What ecologicalphenomenon can explain the differences between the allopatric (whenonly one species lives in that location) and sympatric (when bothspecies live in the same location) populations? Please explain yourargument, you MUST include the terms: competition, competitiveexclusion, realized niche, fundamental niche, resource-partitioning& character displacement).