What is Ecology?

1. What is Ecology?

2. What is Ecology?? • The study of interactionsbetween organisms and their environment. • Tells how living organisms affect each other and the world they live in.

3. Habitat & Niche • Habitat- where a plant or animal lives • Niche-an organism’sway of life (what it does)

4. The Nonliving Environment • Abiotic factors- nonliving parts of an environment. • Examples: air currents, temperature, moisture, light, and soil. • Abiotic factors affect an organism’s life.

5. The Living Environment • Biotic factors- all the organisms in an environment. • All organisms depend on others directly or indirectly for food, shelter, reproduction, or protection.

6. Abiotic or Biotic? Biotic

7. Abiotic or Biotic? Abiotic

8. Abiotic or Biotic? Abiotic

9. Abiotic or Biotic? Biotic

10. Levels of Organization

11. What are the Simplest Levels? • Atom • Molecule • Organelle • Cell • Tissue • Organ • System

12. Levels of Organization • Interactions of an organism are placed into levels by complexity.

13. 1st Level of Organization • Organism:An individual is • made of cells, • uses energy, • reproduces, • responds, • grows and develops

14. 2nd Level of Organization • Population:group of organisms, of the same species, living in the same place at the same time that interbreed

15. Populations • Population Size • Number of individuals in a population • Affects population’s ability to survive • Ex. Smaller populations may be endangered by random events like natural disasters. • Population Density • Number of individuals living in a given area.

16. Population Growth • Populations grow when more individuals are born than die in a given period. • Exponential Growth Curve- Rate of population growth is steady, so population size increases exponentially.

17. Exponential Growth Curve

18. Resources and Population Size • Carrying Capacity • maximum population (as of deer) an area can support without causing deterioration • Density-dependent factors • resources that may be depleted by over population

19. Logistic Model • Model that account for declining resources effect on populations • When population is BELOW carrying capacity, growth is RAPID. • When population nears carrying capacity population growth slows down • When population reaches carrying capacity, equilibrium is reached

20. Logistic Growth

21. Growth Patterns • R-strategists • Populations grow rapidly • Population size drops rapidly in poor conditions • Shortlife spans • Many offspring • Little/no parental care

22. Growth Patterns • K-strategists • Population grows slowly • Density near carrying capacity • Long life span • Few offspring • Long term parental care

23. Hardy-Weinberg Principle • Frequencies of alleles in a population don’t changeunless evolutionary pressures act on the population • These pressures are: • Mutation • Gene Flow • Genetic Drift • Natural Selection

24. Mutation • Any change in DNA • Does not change allele frequencies • Not all mutations affect phenotype • Some mutations change a protein & how it works • Others don’t… • Mutation rates are slow but may make evolution possible.

25. Gene Flow • The movement of alleles in or out of a population • Caused by migration of individuals in or out of a population gene pool • This adds or removes alleles

26. Non-Random Mating • Individuals mate with others nearby or of their own phenotype • Ex. Female peacocks prefer male peacocks with best tail plumage • Alleles for very full tails tend to increase in a population • Inbreeding • Choosing to mate with relatives • Increases the number of homozygous individuals in a population

27. Genetic Drift • Any change in gene frequency, especially due to disaster • Happens more often in small populations • Ex. A fire breaks. Survivors carry the polydactyl (multiple fingers and toes) allele. • Soon, almost the entire population is polydactyl.

28. Natural Selection • A change in the frequency of an allele due to its effects on survival and reproduction. • Ex. Individuals that survive a malaria outbreak carry a gene for mutated hemoglobin- the sickle cell gene. • The frequency of this allele will increase due to repopulation.

29. 3rd Level of Organization Biological Community:All the different populations living in the same place at the same time.

30. Symbiosis Interactions between closely associated, interdependant species. These are • PARASTISM • COMMENSALISM • MUTALISM

31. Parasitism One species benefits but the other is harmed (+/-) • Ex. Leech sucking your blood!!!

32. Commensalism One species benefits; the other is unaffected (+/o) • Ex. Epiphytes grow on trees. They don’t harm or help the trees they live on.

33. Mutualism Both species benefit • Ex. Insects and birds eat nectar from flowers. Pollen gets attached to their feet. At the next flower, they leave some, helping the reproduction of the plant.

34. 4th Level of Organization Ecosystem:Populations of organisms that interact with each other and with the abioticparts of that area. (terrestrial or aquatic)

35. Biomes • A major biological community that occurs over a large area of land. • Examples • Tropical Rainforest • Savannas • Deserts • Taiga • Tundra • Temperate Grasslands • Temperate Deciduous Forest • Temperate Evergreen Forest • Freshwater Communities • Wetlands • Shallow Ocean Waters • Surface of the open Sea • Ocean Depths

36. Cycles in Ecosystems • Elements are recycled through the environment • Carbon • Water • Nitrogen

37. Water Cycle

38. Carbon Cycle

39. Nitrogen Cycle

40. 5th Level of Organization • Biosphere:The portion of Earth that supports life.

41. The Biosphere • Life is in the air, land, fresh water and salt water. • The BIOSPHERE is the part of Earth that supports living things.

42. What level of organization? Organism

43. What level of Organization? Community

44. What level of Organization? Population