1. Using genetics to answer questions about behavior, species, and populations
Molecular Ecology

2. Global warming and Joshua trees
3. Global warming and Joshua trees
4. Demographic survey
9 study sites
2-3 transects per site
Surveyed each tree
Number of branches
Numberof inflorescences
Separated into size classes
5. Problem!
Size class vs. age
Movement between classes
What does a healthy population look like?
How old is too old?
6. Important techniques
PCR
Copies segments of DNA
Double each cycle
35 cycles more than 30 billion copies
7. Important techniques
PCR
PCR-RFLP
Enzymes cut DNA at specific sites
Mutations result in different fragment lengths
Distinguish species
Distinguish individuals
Very cheap, very fast
8. Important techniques
PCR
PCR-RFLP
Microsatellites
Tandem repeats
Mutate rapidly
Cheap, fast
9. Important techniques
PCR
PCR-RFLP
Microsatellites
Sequence
Gene sequence
Expensive, time consuming
Getting cheaper
10. Reproductive behaviour
11. Lekking
Males gather in one location
Females can be choosy
Only best males breed
Lek paradox
Why do subordinate males attend leks?
12. Lekking
Buff-breasted sandpiper
Males lek, females are apparently choosy
13. Lekking
Buff-breasted sandpiper
Males lek, females are apparently choosy
Paternity tests:
14. Lekking
Buff-breasted sandpiper
Males lek, females are apparently choosy
Paternity tests:
40% of broods had multiple sires
Most males sired chicks
15. Monogamy or polygamy?
Why be a promiscuous female?
16. Monogamy or polygamy?
Why be a promiscuous female?
Blue tits:
Socially monogamous
(Actually) polygynous and polyandrous
Male survival correlates with extra-pair copulation
17. Monogamy or polygamy?
Why be a promiscuous female?
Great tits:
Socially monogamous
(Actually) polygynous and polyandrous
Male survival does not correlate with extra-pair copulation
18. Monogamy or polygamy?
Why be a promiscuous female?
Studied during a bad year
Studied during a good year
19. Monogamy or polygamy?
Why be a promiscuous female?
Good genes!
20. Species identification
Cryptic species complex:
Group of organisms that are reproductively isolated (and thus separate species) but are morphologically indistinct
21. Identifying species
Parasitoid wasps
22. Identifying species
Parasitoid wasps
23. Identifying species
Parasitoid wasps
177 morphologically distinct species
313 genetically distinct species
24. Identifying species
Parasitoid wasps
177 morphologically distinct species
313 genetically distinct species
No generalists
25. Identifying species
26. Identifying species
27. 28. Population size
Endangered species
29. Population size
Endangered species
30. Population size
Endangered species
31. Population size
32. Population size
Northern Divide Grizzly Bear Project
Collect grizzly hair
Extract DNA
33. Population size
Hardy-Weinberg Equilibrium:
p + q = 1
p2 + 2pq + q2
34. Population size
Hardy-Weinberg Equilibrium:
p + q = 1
p2 + 2pq + q2
No mutation
35. Population size
Hardy-Weinberg Equilibrium:
p + q = 1
p2 + 2pq + q2
No mutation
No migration
36. Population size
Hardy-Weinberg Equilibrium:
p + q = 1
p2 + 2pq + q2
No mutation
No migration
No selection
37. Population size
Hardy-Weinberg Equilibrium:
p + q = 1
p2 + 2pq + q2
No mutation
No migration
No selection
Random mating
38. Population size
Hardy-Weinberg Equilibrium:
p + q = 1
p2 + 2pq + q2
No mutation
No migration
No selection
Random mating
Infinite population size
39. Population size
2pq
40. Population size
2pq > H: bottleneck
41. Population size
H0 > H: bottleneck
42. Joshua tree populations
Bottleneck
8 microsatellites
Calculates H0 based on k
H < H0 bottleneck
43. Joshua tree populations
44. Joshua tree populations