1. Speciation and types of Isolation

2. If we all shared a common ancestor, then…

3. How did we diverge to become so many species?
Descent with modification-
Different Species

4. Video: How does speciation occur?
Click on the link to play video ~ 2: 40 minutes

5. What is Speciation?
Definition: The formation of new and distinct species in the course of evolution
Species: individuals capable of interbreeding with each other

6. There are two main types of speciation
Allopatric and Sympatric speciation

7. Allopatric Speciation
Definition: new species evolves as a result of geographic isolation

8. Allopatric speciation is caused by Geographic Isolation
Definition: When a population is divided into two or more smaller populations due to PHYSICAL BARRIERS. Limits movement between individuals.
Examples: (pick any 2)
Rivers change course
Mountains rise
Continents drift

9. Harris’s antelope squirrel
White-tailed antelope squirrel

11. Sympatric Speciation
Definition: new species evolves from single ancestor while living in same geographic niche (organism’s “place” in ecosystem)

12. Sympatric speciation is caused by: Behavioral Isolation
Definition: Two species do not mate because of differences in courtship behavior.
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Example:
Blue footed boobies (mating dance)
Birds (mating song)

13. Bowerbirds courtship behavior
Play video
Approximately 2:07 minutes

14. Sympatric speciation is caused by: Temporal Isolation
Definition: Populations may mate at different seasons or different times of day
Example:
1. Frogs mating in early or late summer
2. Skunks mating in late winter vs. early summer

15. Mates during late winter
Mates during late summer

16. Summary video over speciation
Play Video clip

17. Your turn to practice
Read the 10 scenarios on the handout and determine which type of isolation each scenario is describing.
Geographic isolation
Behavioral isolation
Temporal isolation

18. Patterns of evolution

19. Who has seen the movie Divergent?
What was it about?

20. - Tending to be different - Develop in different directions
So what does the word
DIVERGENT
even mean?
- Tending to be different
- Develop in different directions

21. DIVERGENT

22. DIVERGENT

23. DIVERGENT

24. DIVERGENT

25. (aka Adaptive Radiation)
Divergent Evolution
(aka Adaptive Radiation)
Definition: new species evolve from a common ancestor. Results when related species becoming more dissimilar from each other over time.
Time

26. What do these have in common?
Tiktaalik
Human arm
Whale
Lizard
Bird

27. Play from 2:00-3:40 and then 12:31-16:00
Origin of tetrapods
Play from 2:00-3:40 and then 12:31-16:00

28. Origin of tetrapods What does the word “tetrapod” mean?
What are transitional fossils and why are they important?
What evidence suggests that four-legged animals evolved from fish?
Why is Tiktaalik considered a transitional fossil?
Do you think the transition from fish to tetrapod happened quickly or slowly?

29. Origin of tetrapods
Each table has a set of cards. Put them in order from oldest to most recent.
HINTS 
Remember that Tiktaalik is a transitionary fossil
Flat heads evolved later
Look at the evolution of the tail
Look at the digits… webbing and quantity.

30. What is the correct order?
Oldest
Most recent
- Eusthenopteron
- Osteolepis
- Panderichthys
- Tiktaalik
- Acanthostega
- Ichthyostega
- Tulerpeton
- Hynerpeton
- Pederpes

31. What do all these words have in common?
CONFORM
CONGREGRATE
CONSPIRE
CONVERGE
CONSENSUS

32. - Coming closer together
So what does the word
CONVERGENT
even mean?
- Coming closer together

33. CONVERGENT

34. CONVERGENT

35. Convergent Evolution
Definition: unrelated species become similar as they adapt and independently evolve to similar environments over time.
Time

36. What do these have in common?
They swim!
Whale
Ichthyosaur
Porpoise

37. What taxonomic Class do they belong to?
Whale Shark
Ichthyosaur
Porpoise

38. What do these have in common?
They fly!
Bat
Dragonfly
Cardinal

39. What taxonomic Class do they belong to?
Mammal
Bat
Insect
Dragonfly
Aves
Cardinal

40. What do all these words have in common?
COWORKER
COHORT
COLLABORATE

41. Coevolution
Definition: influence of closely associated species evolve together

42. COEVOLUTION EXAMPLE
Hummingbird & Flower

43. COEVOLUTION EXAMPLE
Host and Parasite

44. Read the following sentence silently in your head:
Oh. My. Word. Sometimes. People. Make. Points. By. Writing. This. Way. I. Bet. You. Are. Pausing. After. Every. Word. In. Your. Head. This. Is. A. Lot. Of. Punctuation.

45. Which picture would you guess is PUNCTUATED EQUILIBRIUMor

46. Punctuated Equilibrium
Definition: Evolution is stable for a time and suddenly jumps to new forms

47. If the picture on the left is PUNCTUATED EQUALIBRIUM, how would you describe the one on the right?

48. Gradualism
Definition: New species evolve from existing species through gradual, often imperceptible changes

49. Let’s practice!

50. What Type of evolution is this?
The kit fox lives in the desert where its coat helps disguise it from its predators. The red fox lives in forests where its red coat blends into its surroundings.
Divergent Evolution

51. What Type of evolution is this?
Yucca flowers are a certain shape so only that tiny moth can pollinate them. The moths lay their eggs in the yucca flowers and the larvae (caterpillars) live in the developing ovary and eat yucca seeds.
Coevolution

52. What Type of evolution is this?
There are species, found in Australia, Africa, and America. Though not related, they all evolved the "tools" necessary to subsist on an ant diet: a long, sticky tongue, few teeth, a rugged stomach, and large salivary glands.
Convergent Evolution