1. Unit 2: Evolution Lesson # 8 Other Types of Selection & Speciation

2. Does Natural Selection Go Wrong?
What is Natural Selection?
What are some examples?
Traits and advantages
Could this process go wrong?

3. INTERSEXUAL Selection
Why would these organisms look so obvious?
What is the benefit if they stand out to predators?
What about when the Irish Elk went extinct?

4. What is the benefit of hurting and even killing one another?
Doesn’t evolution decide who gets to live?

5. Natural selection is not the only mechanism through which populations evolve.
Sexual Selection: Adaptations arising through preference by one sex for certain characteristics in individuals of the other sex.

6. Sexual Selection
Could selecting for traits like bright blue feathers ever be a bad thing?
What could be the benefit of selecting such extreme traits?

7. What type of selection shaped each bird?

8. Speciation Where do new species come from?
Reproductive isolation is required for a new species to form

9. Speciation
Geographic isolation occurs when physical barriers divide a population into two or more groups

10. Geographic Isolation Behavioral Isolation Temporal Isolation
Speciation
Geographic Isolation
There are many mechanisms that can create reproductive isolation
Behavioral Isolation
Temporal Isolation
Reproductive isolation – alleles for temperature tolerance also control for pheromones so as one fly became more resistant to cold, it also stopped being attracted to warm weather flies
Behavioral isolation – fireflies flashing at different intervals prevents attraction
Geographic isolation – barriers like rivers, mountains, lakebeds
Temporal isolation – timing prevents reproduction

11. Speciation
A river has cut a deep canyon that has separated a population of rodents into two groups.
This separation is an example of _______ isolation
Geographic

12. Speciation Do the two separate groups stay exactly the same?
What changes may occur?
How do these changes occur? Mutations and natural selection
What is our definition of species? Could a new species form from this separation?

13. Mutations and natural selection create new adaptations
SPECIATION
Mutations and natural selection create new adaptations
A new species cannot form without reproductive isolation.
USE FINCH EXAMPLES FROM THE GALAPAGOS ISLANDS

15. Species Can Shape Each Other
Coevolution
Species Can Shape Each Other
Coevolution is the process in which two or more species evolve in response to changes in each other.
The evolution of hummingbirds’ beaks and plants with deep tubes in their flowers is an example of coevolution.
In natural selection, the selective agent is the: _______
What elements create “the environment”?
Are flowers a part of the environment?
Are birds a part of the environment?
Can two species evolve together?

16. Evolution Vocab Activity
You will create either flashcards or a flipbook of evolution vocabulary
Use these to study for the test
You do need to create a picture for each word
This is due next class