17th Lecture

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 : 

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

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”)  Evolutionarily stable strategies = ESS (a tactic that when  present in a population,  cannot be beaten) : 

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”) Evolutionarily stable strategies = ESS (a tactic that when present in a population, cannot be beaten) John Maynard Smith

Evolution of Self Deceipt Subconscious mind Polygraph playback experiments : 

Evolution of Self Deceipt Subconscious mind Polygraph playback experiments

Slide4: 

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 + 0 Population A, the commensal, benefits whereas B, the host, is not affected Amensalism – 0 Population A is inhibited, but B is unaffected Neutralism 0 0 Neither party affects the other __________________________________________________________________

Exploitation competition (resource depression) Interference competition (direct antagonistic encounters): 

Exploitation competition (resource depression) Interference competition (direct antagonistic encounters)

Slide6: 

Complex Population Interactions Rob Colwell

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): 

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)

Slide8: 

“Cleaner” fish — Saber toothed blenny

Slide9: 

Honey guide and honey badger (ratel)

Plant-pollinator, plant seed dispersal (flowers, fruit)Carbohydrate reward (nectar, fruit pulp)Pollinating “vectors” — high degree of plant-animal specificity assures that pollen will not be wasted.Costs versus benefits to both plant and pollinator.Must provide large enough reward to make it worthwhile for pollinator to visit flower, but small enough to assure that the pollinator will continue to look for another flower (in order to move pollen): 

Plant-pollinator, plant seed dispersal (flowers, fruit) Carbohydrate reward (nectar, fruit pulp) Pollinating “vectors” — high degree of plant-animal specificity assures that pollen will not be wasted. Costs versus benefits to both plant and pollinator. Must provide large enough reward to make it worthwhile for pollinator to visit flower, but small enough to assure that the pollinator will continue to look for another flower (in order to move pollen)

Euglossine beesOrchid fragrances (epiphytes)Male bees use orchid chemicals as basefor production of pheromones to attractfemale bees (travel up to 23 km)pollinate rare and diverse orchids,allowing sparsely distributed plantsto occur at astonishing low densities : 

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

Heliconius tropical butterfliesget amino acids from pollen: 

Heliconius tropical butterflies get amino acids from pollen Larry Gilbert

Slide13: 

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 735 39.1 239 439 Grazing in shade 55 2.9 18 21 Standing in sun 146 7.8 48 46 Standing in shade 257 13.7 84 17 Lying in sun 503 26.8 164 69 Lying in shade 143 7.6 47 17 Walking 39 2.1 13 3 ______________________ Total 1878 100.0 612 ________________________________________________________

Slide14: 

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 2.34 58 69 Nonassociated 1.71 26 31 Steps, N = 62 Associated 20.1 7 11 Nonassociated 32.1 55 89 Feeding/step, N = 59 Associated 0.129 52 88 Nonassociated 0.051 7 12 __________________________________________________________ Harold Heatwole