Chapter 18: The Ecology of Organisms & Populations

A) Box: Biology and Society: The Human Population Explosion

The increase in the human population is affecting the rest of our world (fig 1);
but damage to the environment is due to population growth & non-sustainable consumption
This has data: World Clock

B) An Overview of Ecology

2. Define ecology: interactions between organisms & their environment:
3. Distinguish between abiotic: non-living chemical & physical factors, but NOT a dead tree:
   
4. biotic factor: anything that affects a living organism that is itself alive
5. biotic material: any material that is originated from living organisms
   
6. Humus is the biotic material in soil
   
7. 
   
8. Ecology as scientific study: fig 2, ~ 6 USGS scientists near Bailly/Chellburg. 
   
9. PNC: aquatic botanists: Robin, Mitch, & animal ecologist Vanessa
10. Our Dunes are famous in Ecology because Henry Cowles studied succession, at the dunes
    
11.  
    
Ecology: A hierarchy of interactions: 4 levels of ecology, fig. 4:

12. Organismal: how does one species fit into its environment?, what adaptations (see below)?
    
13. Population (all individuals of one species): factors affecting one species population density & growth
    
14. Community: interactions between all individuals & species living in a defined area:
    
15. Ecosystem: community & abiotic environment
16. Biosphere is global ecosystem
    
17. 
    
18. Ecology & environmentalism.
John Muir/Sierra Club. Robert Redford: NRDC, Lions for Lambs, Greenpeace,
Although there are 1000's of environmentalist groups, they have no power,
& governments are too close to large corporations, who don't want change
The solution to Global Warming is to Pay a Tax on ENTIRE WORLD's use of fossil fuels


19. The significance of Rachel Carson's, fig 4, book Silent Spring. fig 5 is
    
20. Presistent pesticides like DDT were killing wildlife, especially carnivores
    
21. but the issues apply to us too.  EPA's origins
    

CHECKPOINT p 382
1. Define ecosystem, & the four levels of ecology
2. Is the biosphere a global community or global ecosystem?
3. What kinds of chemicals did Rachel Carson identify as harming wildlife?

C) The Evolutionary Adaptations of Organisms
Charles Darwin was an ecologist.  He studied how organisms are adapted to their environment. 

Abiotic factors of the biosphere

2. The biosphere is patchy: fig. 6: global carbon density, due to climate & rocks
   
3. fig. 7 = regional, dune & swale,
4. Habitat defines the specific environment in which a species lives
   
5. The major abiotic factors affecting the distribution of life in the biosphere:
   
6. World biomes are in the next chapter
7. 
   
8. Producers are at the base of all food chains - so they limit biomass
   
9. sunlight: limits photosynthesis.  In water, light penetrates only several meters
   
10. water: limits photosynthesis: forest > prairie, also limits animals
    
11. temperature: limits photosynthesis, fig. 8: mineral/thermal pool: Archaea
12.      going north deciduous > conifer, & only large animals live near Poles
    
13. wind, rocks & soil, Bristlecone pine, images,
14. periodic disturbances: earthquakes, lightning (or fire is used removes unwanted species), fig 10, etc.
    

Adaptations are INHERITED responses to the environment

6. Acclimations: changes individuals make, eg animal fur in winter, hemoglobin increases at altitude
7. Three kinds of Adaptations: all species have physiological, anatomical & behavioral adaptations
   
8. 1) physiological: fig 11, lizards adapted to deserts > ectotherm, animal fur, hemoglobin evolution
9. 2) anatomical: our skeleton is a work in progress, scroll for hearts, also wings, fins, everything?
   
10. 3) behavioral, fig 12, Winter: bundle up, or migrate or hibernate, behavioral thermoregulation,
    

CHECKPOINT p 386
1. What is the importance of solar energy to life on earth?
2. Why do an organism's adaptations limit their geographic distribution?
    Are there any exceptions?
3. What is acclimation?

Next is Friday lecture
D) Population Ecology: the dynamics of species populations & how populations interact with the environment

7. Population: fig 13: prairie dog town, human, some defined area (or volume), tree ID
8. Population density: #/area: use sweep net for insects, (gets many species), human census, tree ID
9. mark-recapture method: less disturbance, used with vertebrates
   
10. Hobart, fig 14, steps: capture, mark, release & recapture: then calculate
11. 
    
12. Patterns of dispersion
    
clumped: common if social interactions &/or heterogeneous environment, fig 15, school of fish
uniform: less common, competition between pairs e.g. eagles, fig 15: penguins nesting

13. random: rare, fig 15, species of trees in rainforest
14.  
15. Population growth models
16. Exponential growth: fig 17, in lab Ex 12, no restrictions, e.g. invasive species, as no competition/predator
Logistic growth: in stable ecosystems species' populations level off at their carrying capacity
The birth rate and death rate are equal, until something changes in the environment, fig 21

17. 
    
18. Regulation of population growth:  (scroll to last part).
19. Density-dependent: fig 20, 21: increasing density reduces resources/individual:
    
20. = intraspecific competition, e.g. food supply, waste disposal: each species is at its carrying capacity
21. 
    
22. Density-independent: fig. 22: aphid population crashes due to bad weather, any catastrophe
    
23. 
    
24. Predator/prey cycles: boom-and-bust: fig 23, hare busts then lynx, hare booms then lynx.
    
25. netlogo online simulations, topics (scroll): art, all sciences, math, games
    
26. 
    
27. Human population growth, & in lab Ex 12
    
28. Exponential growth for last 10,000 years fig 24, fig 25: birth rate > death rate 
    
29. Catholic Italy population is steady (= contraception?): immigration + births = emmigration + deaths,
    
30. USA population is increasing, much is immigration
    
31. 
    
32. Age structure diagrams, fig 26, predict changes in a population, & help predict social conditions
33. Pyramid is due to birth rate > death rate. Scroll for other shapes
    
34. USA baby boom: for 20 years after WWII: age 43 to 63 is widest
    

A demographic transition: moves from "pyramid" to "pole" shape = fewer births/female

35. Requires better social conditions, how will they occur in developing countries?
36. These countries are not being helped enough - like the poor in the USA
37. Europe has fewer problems
    
38. 
    
39. Technology, & destruction of natural environment, including wildlife, natural areas, etc.
    
40. increases Earth's carrying capacity of humans > more of the above
    
41. Loss of Amazon..global loss..my home page..World Resources Institute..

CHECKPOINT p 397
1. Relationship between a population & a species?
2. Current human population? (will NOT be on final)
3. Guppies in an aqurium, double food / day, no change in population, why?
4. Which factor affecting human population growth, is most density independent?:
    1) lower fertility due to hormone imbalance caused by crowding
    2) famine    3) mass drowning due to weather 
    4) epidemic of deadly contagious disease  5) freezing deaths due to lack of housing
5. If the population cycles of lynx & hares is influenced by the nutritional value of plants,
    what new research topic can be studied?
6. If a population's growth rate levels off, what has happened?
7. Math Q. on population growth, like lab ex., skip here

E. Life Histories and Their Evolution

    Life tables & surviviorship curves fig 28: three types of survivorship curves
Type I: human in developed countries, & some species, most survive to be elderly, implies care for young
Type II: common, seen in hydras, some rodents, chances of dying change little with age
Type III: common, most offspring die quickly, was/is it ever true of humans?

   Life history traits as evolutionary adaptations

17. Some species have opportunistic (r) life histories, ~ Type III, short lived, many offspring
    
18. has advantage in unstable envrionment
19. 
    
20. Others have equilibrial (K) life histories, Type I, long lived, few offspring
    
21. has advantage in stable environment
22. 
    
23. r/K selected scroll to features
scroll to Table: compares r & K selected: Table 2 in textbook
24. Some species loose most offspring early on (r), but survivors live long (K): trees, sea turtles
25. 
    
26. SKIP Guppy Life Histories:
    
27. peppered moth evolution:
28. during industrial revolution moth darkened: trees were black with soot, now light again
    

CHECKPOINT P 402
1. Compare opportunistic & equilibrial key characteristics = of r & K selected organisms?
2. What is the key feature of the Type II survival curve?

Evolution Connection: Testing a Darwinian Hypothesis: Natural Selection on the American Plains
The physiological, anatomical & behavioral adaptations of the pronghorn antelope to the plains