-
- In-class review and discussion of HW2
-
- Handout Guidelines for answering short answer questions
-
- Lecture clarification sympatric speciation, character
displacement
2. Animal Behavior, Lec. 6, BIOL 4518 Sympatric speciation
-
- Who? Among members of thesamepopulation
3. Sympatric Speciation
-
- Sympatric speciation is a theory
-
-
- Does this happen in nature?
-
-
- Is instantaneous or gradual more likely to be a mechanism
used?
4. Sympatric speciation
- Mechanisms for restricting gene flow in a population
-
-
- Is behavioral isolation involved?
5. Reproductive character displacement
-
-
- Females choose among variation in male traits
-
-
- Receiver preference function
-
- Male character divergence
-
-
- Over time key traits in males become more and more
different
6. Reproductive character displacement
-
- Is low hybrid fitness required?
- How do hybrid offspring have low fitness?
7. Reproductive character displacement
- Evidence supporting this theory
-
-
- Cause of low hybrid fitness:
8. Reproductive character displacement
- Evidence supporting this theory
-
-
- Value which females discriminate: frequency of pulses
-
-
- Cause of low hybrid fitness: 3N are not viable
9. Summary Reproductive Character Displacement and Sympatric
Speciation
-
- restrict gene flow within a pop.
-
- Instantaneous: Polyploidy
-
- Gradual: Female discrimination and male character
divergence
10. Geomagnetism: Earth's Magnetic Field Gary A. Glatzmaier 11.
Geomagnetism: Earth's Magnetic Field Gary A. Glatzmaier
- Why does the Earth have a magnetic field
-
-
- Iron-rich magma in the earth's crust rises with heat and sinks
with cooling generating the field
12. Geomagnetism: Earth's Geomagnetism: Earth's Magnetic Field:
Animal navigation
-
-
- North and South magnetic poles reverse
-
-
- Evidence in tectonic plates on sea floor that preserve the
polarity as the new magma cools
-
- Field strengthens and weakens
-
-
-
- the dipole moment will decay in about 1,300 years.
- How often does the magnetic field reverse?
-
- During the past 100 million years, the reversal rates vary (5
thousand years to 50 million years).
-
- Last reversed 750,000 - 780,000 years ago.
13. Geomagnetism: Pigeon navigation
- Pigeons navigate in overcast skies
- Suggest they are using magnetic field
14. Geomagnetism: Pigeon navigation
- Pigeons navigate in overcast skies
- Suggest they are using magnetic field
15. Geomagnetism: Pigeon navigation
- Pigeons navigate in overcast skies
- Suggest they are using magnetic field
16. Geomagnetism: Pigeon navigation
- Pigeons navigate in overcast skies
- Suggest they are using magnetic field
17. Electromagnetic Fields: Animals
- In addition to the use of the geomagnetic field for
navigation,
- Some animals generate their own electric field for example for
prey detection
18. Summary Geomagnetism, Electromagnetic fields
- Electromagnetic fields generated by animals
19. Time circadian rhythm
- Clock is affected by environmental cues
- Clock is not affected by environmental cues
- Conclusion somewhere in the middle; free-running cycle updated
with some environmental cues
20. Organization of clocks and behavior
- Clock located in central place
- Receives input and adjusts
- Sends signals to other behaviors
21. Organization of clocks and behavior
- Clock located in central place
-
-
- Suprachiasmic nucleus (SCN)
- Receives input and adjusts
- Sends signals to other behaviors
22. How is a clock made
23. How is a clock made 24. Cycles/Rhythms
25. Cycles/Rhythms 26. Circadian cycles
27. Lunar Cycles
28. Lunar cycles - cues
29. Lunar Cycles - tides 30. Tidal cycles
- Intertidal pools of various heights
- Encysted (18hr) and free swimming (6hr)
- Cycle remain in pools during flooding
- Encyst for 2 high tides and one low tide
- Faster rhythms and change in phase and duration on lower tide
pools
31. Which cycle is the cue?
- Intertidal brown shrimp live in pools created at high tide
- They are exposed to both diurnal and tidal cycles
- What are cue are they using?
32. Which cycle is the cue? 33. Which cycle is the cue? 34.
Which cycle is the cue? 35. Which cycle is the cue? 36. Seasonal
Cycles
- Hibernation without external cues
37. Multiple Years
- Spend most of life in ground in larval stages
- Emerge every 13 or 17 years
- Co-occur every 221 years!
- Emerge within a few days of each other
- Several species identified
38. Multiple Years
- Can sympatric speciation occur by temporal displacement?
-
- Why would this be controversial, given what we have been
discussing?
- What would you expect to observe if sympatric speciation
occurred?
39. Multiple Years 40. Multiple Years
41. Multiple Years 42. Multiple Years
- Suggests single gene change speciation event
43. Summary on cicadas
- Sympatric speciation through timing?
44. Combinations of cycles
45. Relative vs. absolute time 46. Clock shifts
- Clock shifted pigeons change
47. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62.
63. 64.