1. What biodiversity is, why it exists, and what affects it Notes start date: _____ Relevant B&K: Ch 7

2. Using diversity indices (plural of index)
Simpson’s Diversity Index for finite populations:
measures the probability that two randomly selected individuals from a sample will belong to the same category (often species, in our case with stream study, to family level).

3. Simpson’s Index Continued
n = the total number of organisms of a particular species N = the total number of organisms of all species
This version of Simpson’s diversity index ranges between 1 (low diversity) and infinity, where larger numbers mean higher diversity.

4. Example: (p. 94 of Biozone)
Species # of individuals
common backswimmer 12
stonefly larva 7
silver water beetle 2
caddisfly larva 6
water spider 5

5. Other calculated indices
HBI: Hilsenhoff Biotic Index Tolerance values range from 0 to 10, with 10 being most tolerant to organic pollution and 0 being least tolerant to organic pollution
Total of HBI values =
# collected in the entire sample
Dr. William Hilsenhoff came up with the HBI in 1977

6. Other Calculated Indices
EPT Index:
Add the number of different types of organisms belonging to the 3 orders: Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies) together. 
(# of E types = )+ (# of P types=)+(# of T types=) = EPT index=_____

7. Determine which words go with which pictures
Make sure you identify the ecosystem and list all of the minimum necessary requirements for any ecosystem. Be able to explain all choices, every person in group has to be able to explain all. First group done and correct gets prizes.

8. Biodiversity Biodiversity (biological diversity):
-the number of different species in an area (ecosystem)
-the relative numbers of individuals of each species

9. And more specifically-
Genetic diversity- total number of genetic characteristics of a specific species, subspecies, or group of species
Habitat diversity- the different kinds of habitats in a given unit area
Species diversity:
-species richness (the total number of species)
-species evenness (relative abundance of species)
-species dominance (most abundant species)

10. Species Richness: Temporal and spatial variations in tidepool fish assemblages of the northeast coast of Brazil, Biota Neotropica

11. Species Evenness

12. Biodiversity and Healthy Ecosystems
Healthy natural habitats usually have more biodiversity than damaged or degraded ones

14. How did biological diversity come about? (7.2 in B&K)
Biological evolution: the ___________ in inherited characteristics of a pop’n from _________ to __________
(Charles Darwin, 19th century)
New species arise as a result of ___________ for resources and the _____________ among _____________ in their ____________ to environmental conditions

15. Biological evolution and Nat’l selection
Since the ____________ continually changes, __________ individuals are best adapted changes too.
When there is ________ within a species, some _________ may be better ________ to the environment than others.

16. Natural selection
Organisms whose ___________characteristics make them better able to _________ and __________ in their environment leave more ________ than others, and their ____________ form a larger prop. of next gen. (called natural selection)

17. 4 factors of natural selection
____________ of _________ from one ______ to the next, and some _________ in these traits
___________ variability
___________ ___________ that varies with the environment
_________ of the environment on survival and reproduction

18. Reading Quiz Review: Hutchinsonian Niche

19. Ecological Niche
The ecological niche of an organism depends not only on where it lives but also on what it does. By analogy, it may be said that the habitat is the organism's "address", and the niche is its "profession", biologically speaking. -W.B. Saunders, Fundamentals of Ecology

20. Example: Niche (pronounce it “nitch,” or “neesh”)
Oak trees:
Absorb sunlight via photsynth.
Abs. water and minerals from soil
Provide shelter for animals and other plants
Act as support for creeping plants
Serve as food source for animals
Cover the ground with dead leaves in Fall

21. Keystone Species
A keystone species occupies a very specific niche in an ecosystem. This species plays a key role in contributing to the biodiversity in the ecosystem. **these species are more important to an ecosystem than one would expect based on their abundance

22. Examples of Keystone Species
Black-tailed prairie dog in US Southwest
Burrows act as homes to other creatures, including: burrowing owls, badgers, rabbits, black-footed ferrets, snakes, salamanders, insects
Burrowing loosens and churns the soil, increasing ability to sustain plant life
Feeding and foraging allows a more nutritious and diverse mixture of grasses and forbs to grow, which attracts an array of grazing wildlife
Food source for: endangered black-footed ferret, swift fox, coyotes, hawks, eagles, badgers

23. Other examples of Keystone Species
Pisaster ochraceus
Enhydra lutris

24. Geographic isolation  different species
If species become geographically isolated for a long time, it is possible for the populations to change so much that when they are brought back together they are unable to reproduce. Results in two new species.

25. Example of Geographic Isolation

26. Impacts of loss of geographic isolation
Loss of geographic isolation can also lead to new species: One population of a species migrates into a habitat previously occupied by another population of the same species, leading to a change in gene frequency. Natural selection in combination with geographic isolation and subsequent migration can lead to new dominant genotypes and new species.

27. Example: loss of geographic isolation

28. Discussion Questions: Geographic Isolation Drives Evolution of Hot Springs Microbe
State the genus and species of the microbe in the article. To which domain does this microbe belong? List the needs of Sulfolobus islandicus (measured niche). Explain the aim, design, and findings of this study

29. Discussion Questions: Evidence for Speciation
Identify two different species that live in different regions and have been observed to have different genetic characteristics. List the two geographic locations as well. Explain the aim, methods, and results of Diane Dodd’s fruit fly experiments.

30. Factors affecting biodiversity (Table 7. 2 p
Factors affecting biodiversity (Table 7.2 p. 133 shows quick increase/decrease factors)
Anthropogenic (human) effects:
habitat removal and alteration, leads to
habitat fragmentation (isolates populations from one another, cuts off potential for repopulation)
Overharvesting
Increased demands for food production are
further accelerating the rate of conversion
of lands with moderate agricultural value to
farmland. In settled parts of Canada, 90% of
wetlands have been drained.
(Redpath Museum, Quebec)

31. Anthropogenic Factors Continued
Pollution- organic chemicals, fecal coliforms, nitrogen and phosphorous build-up from fertilizers
Introduction of
non-native species

32. Anthropogenic effects: continued
Urbanization and sprawl
Climate change- some have nowhere suitable, some cannot reach anywhere suitable

33. Natural Factors -latitude (generally greater at lower), biomes
-soil type: sandy vs. clay-filled
-soil topgraphy: slope, aspect (direction of slope), elevation, nearness to drainage basin

34. -moderate environmental disturbance (fire in forests and grasslands)
-number and kinds of plants
-climate change

35. Ecological Gradient vs. Zonation
Ecological gradient: Change in the relative number of species over an area or a distance Zonation: Division of an ecosystem into distinct zones that experience similar abiotic conditions BIOZONE p. 21

37. Taxonomy Kingdom Animalia Phylum Arthropoda Class Insecta
Order Ephemeroptera
Family Ephemerellidae
Genus Ephemerella
Species E. Inermis