University of Phoenix Sci256 Week 2 material Ecosystems

1. University of PhoenixSci256 Week 2 materialEcosystems Ch 5,6,9,10Ecosystems and Energy, Ecosystems and Living Organisms, Ecosystems and the Physical Environment,Major Ecosystems of the World, Controlling Pests

2. Ecosystems, Biogeochemicals, Energy, and Trophic PyramidsChapter 5 (and chapt. 9 combined)

3. Ecosystems And Energy Energy Laws of Thermodynamics Photosynthesis/Respiration Trophic Pyramids Energy Flow Food Webs Productivity

4. Ecology • = The study of relationships between organisms and their environment. • Environment= biotic and abiotic factors that affect an organism during its lifetime. • Abiotic factors:nonliving parts of the environment - water, minerals, sunlight, climate. • Biotic factors:organisms that are a part of the environment

5. Stand and Deliver • Nearby (Maryland or your home) biotic components?

7. What is a Biogeochemical? Bio = life Geo = earth Chemical = chemical Chemicals that comes from the earth needed for life!

8. What a chemical is An atom or collection of atoms (molecules)

9. Chemicals of Life

10. Moving chemicals around… What moves them?

11. Energy

12. Laws of Thermodynamics First Law (Conservationof Energy) Energy is neither created nor destroyed; it is always conserved. Second Law Energy always tends to go from a more usable form to a less usable form, so the amount of energy available to do work decreases (entropy occurs).

14. Consequence Of Laws Of Thermodynamics For Living Organisms Organisms require a constant input of energy to maintain a high level of organization. “Feed Me Seymour!” – Little Shop of Horrors

15. This Slide is Yellow Types of Energy Systems

16. Photosynthesis (Transformation of Light Energy) 6 CO2 + 12 H2O + radiant energy C6H12O6+ 6 H2O + 6 O2 Stores energy in chemical bonds

17. Respiration (Transformation of Chemical Energy) C6H12O6 + 6 H2O + 6 O2 6 CO2 +12 H2O + energy Provides energy for “work”

18. Ecological Studies Show How the Whole System Works. • Focus: • The roles played by members of a community • 2. The energy/resource structure of the system.

19. Ecosystem Organization Each system can help clarify different issues. 1. Trophic Pyramids 2. Food Webs 3. Nutrient Cycles

20. (Autotrophs and Heterotrophs)

24. Pyramids of Energy Suggests: • 1. The number of trophic levels are limited. At each trophic level, there is a dramatic reduction in energy. • 2. Eating at lower trophic levels means more resources are available.

26. Pyramids of Energy Suggests: 1. The number of trophic levels are limited. At each trophic level, there is a dramatic reduction in energy. • 2. Eating at lower trophic levels means more resources available. • 3. Movement up the pyramid explains the problems of Biological Magnification (DDT, PCBs, etc.)

27. Biological Magnification • Concentration of a compound can increase at higher trophic levels because each individual in a higher trophic level must eat many individuals of a lower trophic level to survive. • Although the energy acquired by eating those organisms from a lower trophic level is used, the toxic compounds may remain (Especially true for compounds that are stored in fats and are not easily broken down.).

29. Food webs • Are interlocking food chains based on which organisms eat which. • Arrows show the direction of food/energy flow

30. Ocean Food Web

31. Ecological Pyramids • Pyramid of energy • Pyramid of numbers • Pyramid of biomass • Gross Primary Productivity= total amount of energy captured by photosynthesis for an ecosystem.

32. Keystone Species Food webs suggest that keystone species may be important. Changes in one species may dramatically change the entire ecosystem through links in the web. Keystone Species = Species whose presence is essential to community function and stability (e.g., Krill in Antarctica).

34. Evolution, Natural Selection, and Communities

35. Topics And Objectives Evolution by Natural Selection Community Species Interactions Species Diversity Succession

36. Evolution and Natural Selection The Underlying Mechanisms of Species Diversity

37. Charles Darwin "There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone on cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved.“ --The Origin of Species

38. Charles Darwin Darwin was born into the family of a prominent physician on February 12, 1809, in Shrewsbury, England. His mother was the daughter of Josiah Wedgewood, founder of the famous pottery firm. In 1825 Charles entered the University of Edinburgh to become a physician. Two years later he entered Cambridge University to study for the clergy. Grantham

39. Charles Darwin In 1831 Darwin joined the HMS Beagle as the naturalist for a circumnavigation of the world; the voyage lasted five years. It was his observations from that trip that lead to his proposal of natural selection to explain the diversity of organisms. It was not until 1859 that Darwin finally published his Origin of Species.

40. "The most curious fact is the perfect gradation in the size of the beaks in the different species of Geospiza, from one as large as that of a hawfinch to that of a chaffinch, and (if Mr. Gould is right in including in his sub-group, Certhidea, in the main group), even to that of a warbler. The largest beak in the genus Geospiza is show in Fig. 1, and the smallest in Fig. 3; but instead of their being only one intermediate species, with a beak of the size shown in Fig. 2, there are no less than six species with insensibly graduated beaks. The beak of the sub-group Certhidea, is shown in Fig. 4. The beak of Cactornis is somewhat like that of a starling; and that of the fourth sub-hroup, Camarhynchus, is slightly parrot-shaped. Seing this gradation and diversity of structure in one small, intimately related group of birds, one might really fancy that from an original paicity of birds in this archipelago, one species had been taken and modified for different ends [stress added]." Charles R. Darwin, 1845, The Voyage of the Beagle [Edited by Leonard Engel, 1962, NY: Doubleday], pages 380-381. Darwin’s Finches

41. Darwins’s Four Premises • Each species produces more offspring than will survive to maturity. • Individuals in a population exhibit variation. • There are limits on population growth imposed by the environment. • There is differential reproductive success among individuals within a population.

42. What is Evolution? • Descent with modification. • Change in the genetic structure of a population.

43. Mechanisms That Change the Genetic Structure of a Population And Cause Evolutionary Change? • Genetic mutations • Genetic drift (Isolation of populations and different accumulations of mutations) • Founder effect (Small initial reproductive populations with limited genetic diversity) • Natural selection (Differential reproductive potential)

44. What Is Natural Selection? • Differential survival and reproduction among individuals of a population. • Response to selection pressures. • Genetic variations refer to the number of individuals within a population each having a unique combination of traits.

45. Relationship of Evolution and Selection Pressures to Environmental Science • 1. Biodiversity arises through evolution. • Human disturbance changes selective pressures. • Conservation of individual species.

46. Process of Evolution through Natural Selection • 1. Overproduction • Resources limit population growth • Heritable variation in traits. • Differential survival and/or reproduction

47. Potential Selective Pressures Abiotic Temperature Precipitation pH (acidity) Biotic Predation Disease Competition

48. Types of Selection

49. Stabilizing Selection

50. Directional Selection