1. Species Diversity
Ch. 4

2. APES
Put your cycles book in the bin. If it doesn’t fit set it on the counter next to the bin. Write name on rubric, put inside cover.
Everything away except a writing utensil.

3. As environmental conditions change, the balance between formation of new species and extinction of existing species determines the earth’s biodiversity.

4. What is Speciation?
Formation of a new species

5. How does Speciation occur?
Biological barriers prevent similar species from producing viable and fertile offspring

6. Isolating mechanism: Geographic Isolation (pre-zygotic)
Separation of of species by a geographical feature such as a river, mountain range, ocean, or desert

7. Harris Antelope Squirrel and Tassel Eared Squirrel in the Grand Canyon

8. Isolating mechanism: Reproductive Isolation (post-zygotic)
Interbreeding occurred
Result: Unhealthy and Sterile if born at all

9. Can a zebra and a horse reproduce?
Horse has 64 chromosomes
Zebra has 32/46 chromosomes depending on the species

10. Zorse: Infertile organism with 54 chromosomes

11. What is Extinction? Species cease to exist Passenger pigeon Great auk
Dodo
Dusky seaside sparrow
Aepyornis
(Madagascar)

12. How Does Extinction Occur?
Background extinction = species disappearing at a low rate
Mass extinction = Major groups of species wiped out over a short period of time

13. Endemic Organisms are Most Vulnerable
4 – 6 lbs, 25% smaller than on mainland

14. How do Speciation & Extinction Affect Biodiversity?
Speciation – Extinction = Biodiversity Humans major force in premature extinction

15. Species Diversity Species Richness - # of total individuals present
Species Evenness – number of different types of species
Species Dominance – Most abundant species present

16. Describe these communities in terms of species diversity
A  Richness = B  Richness =
Evenness = Evenness =
Dominance = Dominance =
Less Diversity Greater Diversity 25 25 5 5
Circle/HIGH
Equal

17. How to Calculate Species Diversity
Uncertainty = Diversity
See notes on lab sheet
Measures Certainty
Diversity = Dominance = Uncertainty

18. Each Species Plays a Specific Role Called its Niche
Total way of life or role of a species in an ecosystem. Includes: - Physical - Chemical - Biological Factors that a species needs to live & reproduce.

19. Ecological Niches
Niche – species way of life or functional role in an ecosystem (occupation)
Habitat – physical location in an ecosystem (address)

20. No Two Species Can Share the EXACT SAME Niche

21. Fundamental Niche
Full potential range of physical, chemical, and biological conditions and resources a species could theoretically use

22. Realized Niche
Range of abiotic and biotic conditions under which a species actually lives

23. Paramecium Experiment

24. Overlapping Niches

26. Competitive Exclusion Principle
Two species needing the same resource CANNOT coexist due to limited resources Niches of two species CANNOT overlap completely or indefinitely

27. Resource Partitioning
Dividing up of resource so that species with similar needs use them 1) at different times 2) different ways 3) in different places
Fundamental vs. realized niche
Hawks vs owls
Lions vs leopards
warblers

28. © 2004 Brooks/Cole – Thomson Learning Resource Partitioning
Number of individuals
Species 1
Species 2
Region of
niche overlap
Resource use
Niche Specialization
Number of individuals
Species 1
Species 2
Resource use

29. Broad Classification of Species
Generalist
Can live in a variety of habitats and/or feed on a variety of species
Specialists
Specialized to live in specific habitats or feed on specific groups of species

30. Niche separation Niche breadth
Specialist species with a narrow niche
Generalist species with a broad niche
Niche separation
Number of individuals
Figure 4.13: Specialist species such as the giant panda have a narrow niche (left) and generalist species such as the raccoon have a broad niche (right).
Niche breadth
Region of
niche overlap
Resource use
Fig. 4-13, p. 95

31. Classifying Niches Further
Types
Definition
Examples
Native
Non-Native
Indicator
Keystone
Foundation

32. Species Roles Types Definition Examples Native
Normally live & thrive in particular ecosystem
Non-Native
Indicator
Keystone
Foundation

33. Species Roles Types Definition Examples Native
Normally live & thrive in particular ecosystem
Non-Native
Exotic, invasive, alien, introduced, migrating
African bees, kudzu
Indicator
Keystone
Foundation

35. Species Roles Types Definition Examples Native
Normally live & thrive in particular ecosystem
Non-Native
Exotic, invasive, alien, introduced, migrating
African bees, kudzu
Indicator
Species whose population/status serves as a measure of ecosystem health
Birds, fish, amphibians, trout, canaries
Keystone
Foundation

36. Indicators of things like
Habitat loss
Drought
Pollution
UV radiation
Parasitism
Over-hunting
Diseases
Immigration or introduction of predators or competitors

37. Species Roles Types Definition Examples Native
Normally live & thrive in particular ecosystem
Non-Native
Exotic, invasive, alien, introduced, migrating
African bees, kudzu
Indicator
Species whose population/status serves as a measure of ecosystem health
Birds, fish, amphibians, trout, canaries
Keystone
Species whose removal would effect many others as they play a critical role
Bees, lions, decomposers, sea otters
Foundation

38. Sea Otters

39. Species Roles Types Definition Examples Native
Normally live & thrive in particular ecosystem
Non-Native
Exotic, invasive, alien, introduced, migrating
African bees, kudzu
Indicator
Species whose population/status serves as a measure of ecosystem health
Birds, fish, amphibians, trout, canaries
Keystone
Species whose removal would effect many others as they play a critical role
Bees, lions, decomposers, sea otters
Foundation
Play a major role
Beavers

40. Beavers