1. Ecology Study of how organisms interact with each other and with their environment

2. Levels of Ecological Organization Populations –groups of individuals of the same species living together in one area Communities –populations of different species living together in one area Ecosystems –communities and the non-living parts of the environment with which they interact

3. Population Structure Key aspects: Population Size Population Density Population Dispersion

4. Population Size Affects populations ability to survive small populations - more likely to go extinct

5. Population Density Number of individuals per unit area low density can be problem too

6. Population Dispersion Spacing of individuals within the population Random, uniform or clumped

7. Clumped dispersion is when individuals aggregate in patches. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Fig. 52.2a

8. By contrast, uniform dispersion is when individuals are evenly spaced. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Fig. 52.2b

9. In random dispersion, the position of each individual is independent of the others. Overall, dispersion depends on resource distribution. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Fig. 52.2c

10. Survivorship Curves Graphical representation of the survivorship (opposite of mortality) at each age

11. Survivorship Curves Type I –increased risk of dying when old Type II –equal chance of dying at all ages Type III –increased chance of dying when young

12. Fig. 56.10 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 025 Proportion Surviving 1.0 0.1 Human (type I) Hydra (type II) Oyster (type III) 0.01 0.001 50 Percent of Maximum Life Span 10075

14. Fig. 56.11 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 36 9 12 151821 2427 0.002 0.003 0.004 0.005 0.01 0.02 0.03 0.04 0.05 0.1 0.2 0.3 0.4 0.5 1.0 Age (months) Proportion Surviving Poa annua – most like Type II

15. Population Growth Biotic Potential –r –the rate a population would grow at with no limits –intrinsic rate of increase

16. Exponential Growth dN/dt = rN r = (b - d) + (i - e)

17. Fig. 56.16-1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 0510 Number of Generations (t) Population Size (N) 15 1250 1000 750 = 1.0 N 500 250 0 dN dt

18. Carrying Capacity populations eventually reach a limit to their growth K = number of individuals that the environment can support

19. Logistic Growth dN/dt = rN ((K - N)/ K) growth rate slows as the carry capacity is approached sigmoid growth curve (S-shaped) most populations remain constant in size

20. Fig. 56.16 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 0510 Number of Generations (t) Population Size (N) 15 1250 1000 750 = 1.0 N 500 250 0 = 1.0 N Carrying capacity 1000 – N 1000 dN dt dN dt

21. Fig. 56.17 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. N = K Below KAbove K Population Size (N) Population Growth Rate (dN/dt) 0 Negative Growth Rate Positive Growth Rate Carrying Capacity (K)

22. Fig. 56.18 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1915192519351945 a.b. 20010305040 10 8 6 4 2 0 Number of Cladocerans (per 200 mL) 500 400 300 200 100 0Number of Breeding Male Fur Seals (thousands) Time (years) Time (days) Logistic Growth

23. Fig. 56.24 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 4000 B.C. 2 1 3 4 5 6 3000 B.C. 2000 B.C. 1000 B.C. Billions of People 010002000 Significant advances in public health Industrial Revolution Bubonic plague “Black Death” Year

24. Limits to Population Growth Resource limitation- competition predation

25. Community Ecology Study interactions among populations Niche –total of all the ways an organism uses resources in its environment –food consumption, space utilization, temp range, etc... Habitat –physical location

26. Competition struggle between organisms to utilize the same resource when the resource is limited niches overlap and resources are limited

27. Fig. 57.4 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. High tide Low tide C.stellatus fundamental and realized niches are identical when S.balanoides is removed. S.balanoides and C.stellatus competing Chthamalus realized niche Chthamalus fundamental niche Semibalanus realized niche Semibalanus fundamental niche J.H. Connell’s classical study of barnacles

28. Competition “fighting” = interference competition consuming shared resources = exploitative competition

29. Competition Interspecific competition –between individuals from different species Intraspecific competition –between individuals from same species

30. One Possible Result of Competition Competitive exclusion –no species can occupy the same niche indefinitely –one species will be outcompeted and be driven to extinction locally

31. Fig. 57.5 Gausse’s Experiments Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 0 50 100 150 200 408121620244081216202440812162024 a. Days Paramecium caudatum Paramecium aurelia Paramecium bursaria Population Density (measured by volume)

32. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 200 150 100 50 0 40812162024 Days Paramecium caudatum Paramecium aurelia Paramecium bursaria Population Density (measured by volume) b. Competitive Exclusion

33. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. c. 02024161284 Days Paramecium caudatum Paramecium aurelia Paramecium bursaria Population Density (measured by volume) 75 50 25 0 Coexistence…Resource Partitioning

34. Fig. 57.5 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 0 50 100 150 200 408121620244081216202440812162024 a. c. 200 150 100 50 0 02024161284 408 162024 Days Paramecium caudatum Paramecium aurelia Paramecium bursaria Population Density (measured by volume) Population Density (measured by volume) Population Density (measured by volume) b. 75 50 25 0

35. Other Results of Competition Niche overlap can lead to... –Resource partitioning –character displacement

36. –Resource partitioning is the differentiation of niches that enables two similar species to coexist in a community. Fig. 53.2 Fig. 53.3 Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

37. Character displacement is the tendency for characteristics to be more divergent in sympatric populations of two species than in allopatric populations of the same two species. –Hereditary changes evolve that bring about resource partitioning. Fig. 53.4 Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

38. Predation Predator uses prey for food prey evolves defenses, predator evolves adaptations to overcome…arms race

39. Predation Plant defenses against herbivores: morphological - thorns, spines, plant hairs chemicals - secondary compounds

41. Animal defenses against predators: Behavioral defenses include fleeing, hiding, self-defense, noises, and mobbing. Predation

42. Camouflage includes cryptic coloration, Leaf mimic katydid from the Ecuadorian Amazon

43. Deceptive Markings: eyespots http://discovermagazine.com/photos/11-the-calculating-beauty-of-butterflies http://www.flickr.com/photos/la dyoftheflowers/2386058994/

44. Mechanical defenses include spines & shells. african-safari-pictures.com http://www.animalpictures1.com/r-sea-urchin-112-sea-urchin-1958.htm

45. Chemical defenses include odors and toxins – may get them from the plants they eat (ex: monarch butterfly & milkweed) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

46. Aposematic coloration is indicated by warning colors, and is sometimes associated with other defenses (toxins). Fig. 53.6 Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

47. Mimicry is when organisms resemble other species. –Batesian mimicry is where a harmless species mimics a harmful one. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

48. Müllerian mimicry is where two or more unpalatable species resemble each other. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings Fig. 53.8

49. Fig. 57.14 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Heliconius melpomene Papilio glaucusBattus philenor a. Batesian mimicry: Pipevine swallowtail butterfly (Battus philenor) is poisonous; Tiger swallowtail (Papilio glaucus) is a palatable mimic. Heliconius erato Heliconius cydnoHeliconius sapho b. Müllerian mimicry: Two pairs of mimics; all are distasteful.

50. Predation Can promote species diversity predator eats superior competitor

52. Keystone species exert an important regulating effect on other species in a community. Fig. 53.14 Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

53. If they are removed, community structure is greatly affected. Fig. 53.15 Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

54. Coevolution & interspecific interactions –Coevolution refers to reciprocal evolutionary adaptations of two interacting species. When one species evolves, it exerts selective pressure on the other to evolve to continue the interaction. Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

55. The Oogpister Beetle Video http://www.snotr.com/video/4732