Species Interactions

1. Species Interactions Mr. Beaty 2009-10

2. Bellringer • Have notes ready for species interactions discussion. • I will call each up to see their grades after the notes. • Defend the following statement: • Species interactions are the driving force behind natural selection.

3. Ecology terms: • Biotic factors • Abiotic • Niche (Fundamental and Realized) • Competition

4. EQ: How do species interactions drive changes in organisms? • Predator/Prey • Parasitism • Commensalism • Mutualism • Commensalism

5. Predator-Prey

6. Parasatism • Parasitism

7. Mutualism

8. Commensalism

10. Competitive Exclusion • two speciescompeting for the same resources cannot stably coexist • Connell (1961)

11. Competitive Exclusion Principle • Tansley (1917) showed (1) that the presence of absence of a species could be determined by competition with other species; (2) that conditions of the environment (in this case, soil type) affected the outcome of competition; (3) that competition might be felt very broadly at first (i.e., from other vegetation throughout the community); and (4) that the present ecological segregation of species might have resulted from competition in the past.

12. Competitive Exclusion Principle • 2. • Gause: used cultures of protozoans to develop the competitive exclusion princple (1934). • two species cannot coexist on the same limiting resource. Similar results have been obtained for fruit flies, mice, flour beetles, and annual plants: One species dies and the other persists. May requires 30-70 generations for insects.

13. Limiting Resource

14. Resource Partitioning • Charles Darwin noticed that competition is most intense between similar species that require the same resources. • Robert MacArthur studied several species of warblers that foraged in the same tree. A closer look showed that each species hunts for insects in a different part of the tree. • process by which natural selection drives competing species into different patterns of resource use or different niches.

16. of resource partitioning.

18. Coevolution                     Here you can see two Heliconius eggs that have been layed on a passionflower leaf.                                       Here you can see the leaf on one passionflower species which has evolved to "fake eggs" (nectaries) to make the moth think that the leaf is already occupied.

20. Adaptations • Mimicry • Toxins • Aposomatic coloration • Plants: Physical defenese, chemical defenses • Secondary compounds – nicotine, strychnine, poison ivey

22. Batesian Mimicry

23. This tropical ant of the species Cephalotes atratus is infected with a parasitic roundworm that makes its bulbous rear end, called a gaster, look like a juicy red berry. Researchers believe the parasites transform the gasters to trick foraging birds into eating the ants. Birds poop out parasite eggs, allowing the worms to spread to new ant colonies. Coevolution at its best!

25. Ecological Succession • Primary Succession • Secondary Succession • Pioneer Species • Climax Community

26. Ecological Succession

27. Primary or Secondary

28. Primary or Secondary

29. Primary or Secondary

30. Primary or Secondary

31. Primary or Secondary

32. Primary or Secondary

33. Primary or Secondary

35. Bellringer (Begins on pg 436) • How does the greenhouse effect occur? • What is biodiversity? • Compare species richness and species evenness. Compare species diversity and genetic diversity. • Calculate the species richness and species evenness for each island. Island X has 50 individuals of species A, 200 of species B and 2000 of species C. Island Y has 300 of species A, 300 of species B and 500 of 200 of species C and 500 of species D. • Which island has the greatest biodiversity?

36. Environmental Issues • Pollution – smog • Ozone thinning • Global Warming • Acide Rain • Biological magnification • Extinction • Keystone species • Sustainability • Environmental Footprint