1. Leks. Runaway Sexual Selection (Fisher). Handicap Hypothesis (Zahavi)
Leks Runaway Sexual Selection (Fisher) Handicap Hypothesis (Zahavi) Sensory Exploitation Hypothesis (Ryan) Alternative mating tactics Internal versus External Fertilization Satellite males (frogs, crickets) Ecological Sexual Dimorphisms Bower birds Ratites Bushland tinamou
Lecture # 18
28 March 2018

2. Female releases eggs first, then male fertilizes them with his sperm,
Female has the first opportunity to desert, male is left in a “cruel bind”

3. Amplexus

4. Rhea Paternal Care
Emu

5. Ostrich Male Parental Care

6. Emu Male Parental Care

7. Dinosaur fossils suggest that male parental care could be ancestral in birds If so, ratites could have retained the ancestral state And, if so, then female care and biparental care would be derived conditions
A male of the medium-sized predatory dinosaur Troodon (North America late Cretaceous)
brooding a large clutch of eggs. Female archosaurs extract substantial amounts of calcium and phosphorus from their skeletal tissues during egg formation. Histologic examination of cross sections of bones (femur, tibia, and a metatarsal bone) from an adult Troodon found in direct contact with an egg clutch revealed little evidence of bone remodeling or bone resorption, suggesting that the bones were those of a male. Fossilized remains of Troodon and two other types of dinosaurs found with large clutches of eggs suggest that males, and not females, protected and incubated eggs laid by perhaps several females (Credit: Bill Parsons)

9. 13 16 9 20 14 11 15 4 1 7 3 11 5 6

11. Red-eyed Vireo
Ecological
Sexual Dimorphism

12. Four Possible Situations Involving an Individual’s
Behavior and Its Influence on a Neighbor
__________________________________________________________________
Neighbor(s) Gain Neighbor(s) Lose
Individual Gains Pseudo-altruistic behavior Selfish behavior
(kin selection) (selected for)
Individual Loses True altruistic behavior Mutually disadvanta-
(counterselected) geous behavior
(counterselected)
_________________________________________________________________

13. W. D. Hamilton (1964). Kin Selection. Inclusive Fitness
W. D. Hamilton (1964) Kin Selection Inclusive Fitness Hamilton’s rule: r n b – c > r = coefficient of relatedness n = number of relatives that benefit b = benefit received by each recipient c = cost suffered by donor r n b > c “Adaptive Geometry of a Selfish Herd”

14. W. D. Hamilton (1964). Died 7 March 2000. Malarial Hemorhagic Fever
W. D. Hamilton (1964) Died 7 March Malarial Hemorhagic Fever “I will leave a sum in my last will for my body to be carried to Brazil and to these forests. It will be laid out in a manner secure against the possums and the vultures just as we make our chickens secure; and this great Coprophanaeus beetle will bury me. They will enter, will bury, will live on my flesh; and in the shape of their children and mine, I will escape death. No worm for me nor sordid fly, I will buzz in the dusk like a huge bumble bee. I will be many, buzz even as a swarm of motorbikes, be borne, body by flying body out into the Brazilian wilderness beneath the stars, lofted under those beautiful and unfused elytra which we will all hold over our backs. So finally I too will shine like a violet ground beetle under a stone.
W. D. Hamilton (born 1 August 1936, died 7 March 2000, age 63)

15. “Adaptive Geometry of a Selfish Herd”

16. Eusocial Insects. Hymenoptera (“thin wings”)
Eusocial Insects Hymenoptera (“thin wings”) Ants, bees, wasps, hornets Workers are all females Haplodiploidly Isoptera (“same wings”) Termites (castes consist of both sexes) Endosymbionts Parental manipulation Cyclic inbreeding

18. Inclusive fitness should be understood within a multilevel selection
approach, as a nested hierarchy extending from genes, to individuals,
to kin, and finally to even larger groups.

19. White-Fronted Bee Eaters, Kenya (Emlen and Wrege, Cornell)

21. Peter
Wrege
Steve Emlen

22. Helpers at the Nest in White-Fronted Bee Eaters in Kenya
__________________________________________________________________
Breeders r* Number of Cases % Cases
Father x Mother
Father x Stepmother
Mother x Stepfather
Son x Nonrelative
Brother x Nonrelative
Grandfather x Grandmother
Half brother x Nonrelative
Uncle x Nonrelative
Grandmother x Nonrelative
Grandson x Nonrelative
Great grandfather x Nonrelative
Nonrelative x Nonrelative
Total
* r = coefficient of relatedness.
S. T. Emlen and P. Wrege, Cornell

23. Leks. Runaway Sexual Selection (Fisher). Handicap Hypothesis (Zahavi)
Leks Runaway Sexual Selection (Fisher) Handicap Hypothesis (Zahavi) Sensory Exploitation Hypothesis (Ryan) Alternative mating tactics Internal versus External Fertilization Satellite males (frogs, crickets) Ecological Sexual Dimorphisms Bower birds Ratites, Bushland Tinamou
Reciprocal Altruism
Evolution of Self Deceit Subconscious mind Polygraph playback experiments Fool Yourself, The Better to Fool Others

24. Game Theoretic Approaches. Costs versus benefits of behaviors
Game Theoretic Approaches Costs versus benefits of behaviors “tit for tat” strategy can lead to cooperation
“the future casts a long shadow back on the present” -- Axelrod
Evolutionarily stable strategies = ESS -- Maynard Smith
(a tactic that when present in a population, cannot be beaten)

25. Reciprocal Altruism (Trivers 1971). Donor ––> Recipient
Reciprocal Altruism (Trivers 1971) Donor ––> Recipient Small costs, large gains, reciprocated Sentinels Robert Trivers Biological basis for our sense of justice? Friendship, gratitude, sympathy, loyalty, betrayal, guilt, dislike, revenge, trust, suspicion, dishonesty, hypocrisy

26. Game Theoretic Approaches Prisoner's dilemma: Two suspects, A and B, are arrested by the police. The police have insufficient evidence for a conviction, and, having separated both prisoners, each of them is offered the same deal: if one testifies for the prosecution against the other and the other remains silent, the betrayer goes free and the silent accomplice receives the full 10-year sentence. If both stay silent, the police can sentence both prisoners to only six months in jail for a minor charge. If each betrays the other, each will receive a two-year sentence. Each prisoner must make the choice of whether to betray the other or to remain silent. But neither prisoner knows for sure what choice the other prisoner will make. So the question this dilemma poses is: What will happen? How will the prisoners act?

27. Prisoner's Dilemma http://plato.stanford.edu/entries/prisoner-dilemma/
Prisoner B Stays Silent Prisoner B Betrays
Prisoner A
Stays Silent Both serve 6 months Prisoner A serves 10 years
Prisoner B goes free
Prisoner A Prisoner A goes free
Betrays Prisoner B serves 10 years Both serve two years

28. Game Theoretic Approaches. Costs versus benefits of behaviors
Game Theoretic Approaches Costs versus benefits of behaviors “tit for tat” strategy can lead to cooperation (“the future casts a long shadow back on the present” -- Axelrod) Evolutionarily stable strategies = ESS (a tactic that when present in a population, cannot be beaten)
John Maynard Smith

29. Evolution of Self Deceit. Subconscious mind
Evolution of Self Deceit Subconscious mind Polygraph playback experiments

30. Evolution of Self Deceit. Subconscious mind
Evolution of Self Deceit Subconscious mind Polygraph playback experiments Fool Yourself The Better to Fool Others

31. Summary of Direct Pairwise Interactions Between Two Populations
__________________________________________________________________________
Species
Type of Interaction A B Nature of Interaction
Competition – – Each population inhibits the other
Predation, parasitism, + – Population A, the predator, parasite,
and Batesian mimicry or mimic, kills or exploits members
of population B, the prey, host, or model
Mutualism, Interaction is favorable to both (can
Müllerian mimicry be obligatory or facultative)
Commensalism Population A, the commensal, benefits
whereas B, the host, is not affected
Amensalism – Population A is inhibited, but B is
unaffected
Neutralism Neither party affects the other
__________________________________________________________________

32. Indirect Interactions
Darwin — Lots of “Humblebees” around villages

33. Indirect Interactions Darwin — Lots of “Humblebees” around villages
bees —> clover

34. Indirect Interactions Darwin — Lots of “Humblebees” around villages
bees ——> clover

35. Indirect Interactions Darwin — Lots of “Humblebees” around villages
mice ——o bees ——> clover

36. Indirect Interactions Darwin — Lots of “Humblebees” around villages
cats —o mice ——o bees ——> clover

37. Indirect Interactions Darwin — Lots of “Humblebees” around villages
spinsters —> cats —o mice —o bees —> clover

38. Indirect Interactions Darwin — Lots of “Humblebees” around villages
spinsters —> cats —o mice —o bees —> clover —> beef

39. Indirect Interactions Darwin — Lots of “Humblebees” around villages
spinsters —> cats —o mice —o bees —> clover —> beef —> sailors

40. Indirect Interactions Darwin — Lots of “Humblebees” around villages
spinsters —> cats —o mice —o bees —> clover —> beef —> sailors —> naval
prowess

41. Indirect Interactions Darwin — Lots of “Humblebees” around villages
spinsters —> cats —o mice —o bees —> clover —> beef —> sailors —> naval prowess
Path length of seven! Longer paths take longer (delay)
Longer paths are also weaker, but there are more of them
—————————————————>

42. Indirect Interactions
Trophic “Cascades”
Top-down,
Bottom-up

43. Competitive Mutualism

44. Complex Population Interactions
Rob Colwell

45. Mutualistic Interactions and Symbiotic Relationships
Mutualistic Interactions and Symbiotic Relationships Mutualism (obligate and facultative) Termite endosymbionts Commensalisms (Cattle Egrets) Examples: Bullhorn Acacia ant colonies (Beltian bodies) Caterpillars “sing” to ants (protection) Ants tend aphids for their honeydew, termites cultivate fungi Bacteria and fungi in roots provide nutrients (carbon reward) Bioluminescence (bacteria) Endozoic algae (Hydra), “kidnapped” chloroplasts Endosymbiosis (Margulis) mitochondria & chloroplasts Birds on water buffalo backs, picking crocodile teeth Figs and fig wasps (pollinate, lay eggs, larvae develop)

46. Brown Hydra Green Hydra

47. Nudibranchs
Green sea slug
Hydra

48. Runaway Sexual Selection (Fisher). Handicap Hypothesis (Zahavi). Leks
Runaway Sexual Selection (Fisher) Handicap Hypothesis (Zahavi) Leks Sensory Exploitation Hypothesis Internal versus External Fertilization Alternative mating tactics Satellite males Ecological Sexual Dimorphisms Ratites (bushland tinamou) Bower birds Spiteful behavior

49. Summary of Direct Pairwise Interactions Between Two Populations
__________________________________________________________________________
Species
Type of Interaction A B Nature of Interaction
Competition – – Each population inhibits the other
Predation, parasitism, + – Population A, the predator, parasite,
and Batesian mimicry or mimic, kills or exploits members
of population B, the prey, host, or model
Mutualism, Interaction is favorable to both (can
Müllerian mimicry be obligatory or facultative)
Commensalism Population A, the commensal, benefits
whereas B, the host, is not affected
Amensalism – Population A is inhibited, but B is
unaffected
Neutralism Neither party affects the other
__________________________________________________________________

50. Intraspecific competition (between individuals within spp
Intraspecific competition (between individuals within spp.) Interspecific competition (between members of different spp.) Exploitation competition (resource depression) Interference competition (direct antagonistic encounters)

51. Indirect Interactions Darwin — Lots of “Humblebees” around villages
spinsters —> cats —o mice —o bees —> clover —> beef —> sailors —> naval prowess
Path length of seven! Longer paths take longer (delay)
Longer paths are also weaker, but there are more of them
—————————————————>

52. Euglossine bees Orchid fragrances (epiphytes) Male bees use orchid chemicals as base for production of pheromones to attract female bees (travel up to 23 km) pollinate rare and diverse orchids, allowing sparsely distributed plants to occur at astonishing low densities
Dan Janzen

53. Heliconius tropical butterflies get amino acids from pollen
Larry Gilbert

54. Various Aspects of the Association of Cattle Egrets with Cattle
________________________________________________________
Number of
Number Percent Associated Egrets
Category of Cattle Cattle Expected Observed
___________________________________________________________________
Grazing in sun
Grazing in shade
Standing in sun
Standing in shade
Lying in sun
Lying in shade
Walking
______________________
Total

55. Various Aspects of the Association of Cattle Egrets with Cattle
______________________________________________________________________
Number of Times
Mean Count Was Higher
Number Than for Opposite Number of
Per Minute Egret Associated Egrets
Feedings, N = 84
Associated
Nonassociated
Steps, N = 62
Associated
Nonassociated
Feeding/step, N = 59
Associated
Nonassociated
__________________________________________________________
Harold Heatwole

56. Interspecific Competition leads to Niche Diversification Two types of Interspecific Competition: Exploitation competition is indirect, occurs when a resource is in short supply by resource depression Interference competition is direct and occurs via antagonistic encounters such as interspecific territoriality or production of toxins

57. Direct versus Indirect Interactions
Exploitation vs. Interference competition
Apparent Competition
Competitive Mutualism
Facilitation
Food Chain Mutualism
Trophic Cascades (top-down, bottom up)
Complex Population Interactions (Colwell’s Plant-Pollinator System)
Mutualisms
Euglossine bees and orchids
Heliconius butterflies (larval nitrogen reserves)
Cattle Egret Commensalism
Gause’s competition lab experiments

58. Competitive Exclusion
Georgii F. Gause

59. Coexistence of
two species of
Paramecium
G. F. Gause

60. Outcome of Competition Between Two Species of Flour Beetles _______________________________________________________________________________ Relative Temp. Humidity Single Species (°C) (%) Climate Numbers Mixed Species (% wins) confusum castaneum _______________________________________________________________________________ Hot-Moist confusum = castaneum Hot-Dry confusum > castaneum Warm-Moist confusum < castaneum Warm-Dry confusum > castaneum Cold-Moist confusum <castaneum Cold-Dry confusum >castaneum _______________________________________________________________________________

62. Recall the Verhulst-Pearl Logistic Equation
dN/dt = rN [(K – N)/K] = rN {1– (N/K)}
dN/dt = rN – rN (N/K) = rN – {(rN2)/K}
dN/dt = 0 when [(K – N)/K] = 0
[(K – N)/K] = 0 when N = K
dN/dt = rN – (r/K)N2

63. Inhibitory effect of each individual
On its own population growth is 1/K
Assumes linear response to crowding,
instant response (no lag),
r and K are fixed constants

64. S - shaped sigmoidal population growth
Verhulst-Pearl Logistic

65. Lotka-Volterra Competition Equations. competition coefficient
Lotka-Volterra Competition Equations competition coefficient aij = per capita competitive effect of one individual of species j on the rate of increase of species i dN1 /dt = r1 N1 ({K1 – N1 – a12 N2 }/K1) dN2 /dt = r2 N2 ({K2 – N2 – a21 N1 }/K2) Isoclines: (K1 – N1 – a12 N2 )/K1 = 0 when N1 = K1 – a12 N (K2 – N2 – a21 N1 )/K2 = 0 when N2 = K2 – a21 N1
Alfred Lotka Vito Volterra