Chapter 5

1.25.13

• Test on Tuesday

• Quizlet due Tuesday

• Homework: Read 5.2, 5.3, 5.4

Review

• Describe the processes that create a rain shadow

• On a map identify regions of the globe that are affected by rain shadows

• Explain how abiotic conditions determine the characteristics of a biome

Chapter 5Evolution of Biodiversity

Objectives

• Describe the importance of biodiversity.

• Differentiate between species richness and species evenness.

• Utilize Shannon’s index to calculate species diversity.

Question

• Why does a healthy lawn need 4 types of grass?

Levels of Biodiversity

• Does anyone recall the 3 levels of biodiversity?

• Ecosystem

• Species

• Genetic


• In general, will greater biodiversity be found on tended land or untended land?

• Why?


• Of the three levels of biodiversity, which one ultimately determines the other two?

Richness vs. Evenness

• Why is the number of species on earth not a useful indicator of local or regional diversity?

• Species aren’t distributed evenly over the face of the earth.


• If you had to define SPECIES RICHNESS vs. SPECIES EVENNESS, how would you do it?


• Richness: The number of species in a given area

• Gives a sense of the biodiversity in an area


• Evenness: Relative proportions of individuals within the different species

• Are there equal numbers of many species?

• Is the area dominated by one species?


• High Evenness

• All species have a relatively equal number of individuals


• Low evenness

• One species has many individuals

• Other species have only a few


• Could an ecosystem have low evenness and still be rich?

• If two areas have the same richness ...

• The more even ecosystem is considered more diverse

Shannon’s Index

• Used to calculate the biodiversity present in an area

• H = -∑ pi ln (pi)

• Shannon’s Index = [(% A X (ln % A)) + (% B X (ln % B))]

• Example: 3 Species: Species A 75%, Species B 15%, Species C 10%

• Calculate the Shannon’s Index for each sample on the next slide

Sample 1 Sample II Sample III

Species A 24 48 24

Species B 20 40 20

Species C 7 14 7

Species D 3 6 3

Species E 3

Species F 1

Index

Sample 1 Sample II Sample III

Species A 24 48 24

Species B 20 40 20

Species C 7 14 7

Species D 3 6 3

Species E 3

Species F 1

Index 1.15 1.15 1.36

Why is BD Important

• Get out a sheet of paper

• Write a D on the top of your paper

• Walk around and write down the names of 3 people

Why is BD Important

• Everyone remain standing

• I am the disease

• When your name is called sit down

• How many are left standing?

Why is BD Important

• 2 D

• N - Noble Fir

• C - Western Cedar

• M - Vine maple

• H- Hemlock

• W - Fir

• L - Pine

• WP - White Pine

• B - Bigleaf Maple

• WD - Dogwood

• 2-3 of each tree

• Repeat walk around

• Debrief questions

Agenda

• Garbage Patch projects due Tuesday

• Should have completed packet reading

• Completed lab will be due next Friday

Reading Quiz

• Name 1 way in which evolution occurs

• How are artificial and natural selection alike, how are they different?

• How does evolution lead to biodiversity?

• How does geographic isolation lead to reproductive isolation?

Objectives

• calculate diversity values for sampled habitats, using three indices: species richness, Shannon-Wiener, and Simpson’s

• Explain trade-offs involved in establishing biodiversity reserves.

• Understand rationales for maintaining biodiversity when possible.

• Understand subtle differences between the different ways of measuring and defining biodiversity

Berlese Funnels

• What are some possible reasons for low microarthropod captures?

• How could the experiment be altered to obtain better data?

• Use hand lenses and dissecting scopes to determine if you have anything in your alcohol

Schedule

• Go outside and collect sticky traps

• Come inside and begin to crunch data

• Look at photos from yesterday

• Analyze trap catches and gather data

• Work through Berlese Funnel catches

• Start questions

Agenda

• Hope you turned in your garbage patch work

• Chapter 4 and 5 test tomorrow

• Lab due Friday

Objectives

• Explain the terms fundamental niche, realized niche, niche generalist, and niche specialist.

• Relate environmental change to species distribution.

• Compare and contrast major mass extinctions

Question

• Is it better to be mediocre at many things or excellent at one thing?

Niches

• How would you define Range of Tolerance?

• The minimum and maximum amount of any factor that an organism can handle

Niches

• Range of Tolerance

• At either end of the spectrum an organism may survive but not thrive.

Niches

• Fundamental Niche

• The combination of all ideal conditions for an organism

• Determined by abiotic factors

Niches

• How could biotic conditions limit a species range or survival?

Niches

• Realized Niche

• The combination of biotic and abiotic conditions under which an organism survives

• Once realized niche is determined distribution can be understood.

Niches

• Some species can thrive under a wide variety of environmental conditions.

• Large Realized Niche

• Known as NICHE GENERALISTS

Niches

• Some species can only thrive only under a very small set of conditions.

• Small realized niche

• Known as a NICHE SPECIALIST

Niches

• Where do you think generalists are likely to be found?

• Specialists?

Niches

• We’ve seen that environmental conditions determine what lives where.

• What do you think will happen if the environment changes?

Climate Change

• Organisms follow the conditions.

• New areas are colonized by new species.

• How do you think this relates to disease transmission?

Climate Change

• Malaria

Extinction

• 99% of species that have ever lived are now extinct?

• How could environmental change lead to species extinction?

• No where to go.

• Polar Bears

Extinction

• The fossil record shows 5 mass extinctions

• During the last mass extinction, 65 mya, 50% of species were killed by a meteorite impact.

Extinction

• We are currently in the middle of the 6th mass extinction.

• How do you think this mass extinction is different from the others?

Education

Chapter 5