Transcript Summary of Direct Pairwise Interactions Between Two

Kin selection, inclusive fitness
Hamilton’s rule: r n b > c
(coefficient of relatedness)
Pseudo-altruistic behavior
Eusocial Insects
Hymenoptera (“thin wings”)
Ants, bees, wasps, hornets—all workers are females
Haplodiploidly
Isoptera (“same wings”)
Termites (castes consist of both sexes)
Endosymbionts
Parental manipulation
Cyclic inbreeding
“Adaptive Geometry of a Selfish Herd”
Helpers at the Nest in White-Fronted Bee Eaters in Kenya
Reciprocal Altruism (Trivers)
Donor ––> Recipient
Small costs, large gains, reciprocated
Sentinels, selfish callers
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 + forgiveness can lead to cooperation
(“the future casts a long shadow back on the present”)
Evolutionarily stable strategies = ESS
Evolution of self deceit makes for better liars
Subconscious mind
Polygraph playback experiments
Summary of Direct Pairwise Interactions Between Two Populations
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Species
Type of Interaction
A
B
Nature of Interaction
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Competition
–
–
Each population inhibits the other
Predation, parasitism,
and Batesian mimicry
+
–
Population A, the predator, parasite,
or mimic, kills or exploits members of
population B, the prey, host, or model
Mutualism,
Müllerian mimicry
+
+
Interaction is favorable to both (can
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
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Exploitation competition (indirect, resource depression)
Interference competition (direct antagonistic encounters)
Complex Population Interactions
Rob Colwell
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,
and Batesian mimicry
+
–
Population A, the predator, parasite,
or mimic, kills or exploits members of
population B, the prey, host, or model
Mutualism,
Müllerian mimicry
+
+
Interaction is favorable to both (can
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
___________________________________________________________________________________
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), bleaching of coral reefs (coelenterates)
Nudibranch sea slugs: Nematocysts, “kidnapped” chloroplasts
Endosymbiosis (Lynn Margulis) mitochondria & chloroplasts
Birds on water buffalo backs, picking crocodile teeth
Figs and fig wasps (pollinate, lay eggs, larvae develop)
Nudibranchs
Green sea slug
Hydra
“Cleaner” fish — Saber toothed blenny
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)
Dan Janzen
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 butterflies
get amino acids from pollen
Larry Gilbert
Various Aspects of the Association of Cattle Egrets with Cattle
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Number of
Number
Percent
Associated Egrets
Category
of Cattle
Cattle
Expected
Observed
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Grazing in sun
Grazing in shade
Standing in sun
Standing in shade
Lying in sun
Lying in shade
Walking
Total
735
55
146
257
503
143
39
39.1
2.9
7.8
13.7
26.8
7.6
2.1
1878
100.0
239
439
18
21
48
46
84
17
164
69
47
17
13
3
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612
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Various Aspects of the Association of Cattle Egrets with Cattle
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Mean
Number
Per Minute
Number of Times
Count Was Higher
Than for Opposite
Egret
Number of
Associated Egrets
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Feedings, N = 84
Associated
2.34
58
69
Nonassociated 1.71
26
31
Steps, N = 62
Associated
Nonassociated
20.1
32.1
7
55
Feeding/step, N = 59
Associated
Nonassociated
0.129
0.051
52
7
11
89
Harold Heatwole
88
12
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