Raoul Mulder
Animal Behaviour Raoul Mulder
Cooperation I
What is cooperation? A behaviour is cooperative if … i) it provides a benefit to another individual (i.e. the recipient) AND ii) has been selected for because of its beneficial effect on the recipient
Cooperatively breeding vertebrates Example 1:
Dominant breeding pair + subordinate ‘helpers’
Apostlebirds
Subordinates may be nondispersing young from previous breeding attempt, or immigrants Feed and protect young, other members of the group
Banded mongoose
Benefits: improved breeding success 1.2 66
242 162
0
2
3
4
>4
No. of individuals in the group
Breeding success as a proportion of group size
118
No. of fledglings
Carrion crow Corvus corone
0.46 134
75
4
>4
225 173
0.32
2
3
No. of individuals in the group
Benefits: improved breeding success 1.2 66
242 162
0
2
3
4
>4
No. of individuals in the group
Breeding success as a proportion of group size
118
No. of fledglings
Carrion crow Corvus corone
0.46 134
75
4
>4
225 173
0.32
2
3
No. of individuals in the group
Carrion crow groups with helpers breed more often and produce more fledglings
reduced workload Benefits: improved survival 1350
Mean weight of offspring (g)
Mean volume of eggs (mm3)
10
Fairy-wren helpers don’t increase reproductive success ... ... but they allow females to lay smaller eggs, which leads to improved female survival
Pair without help
Pair with help
5
Pair without help
1.0
Probability of surviving
1150
0.5
Pair without help
Pair with help
Pair with help
Cooperative bacteria Example 2:
Production of iron-scavening molecules ‘siderophores’ Vibro tasmaniensis bacterial cells with siderophores
Cooperative ‘slime cities’ in dental plaque and sink plugholes
Siderophores released into extra-cellular space; sequester iron Other bacterial cells benefit from access to ‘public goods’
Cleaner fish mutualisms Example 3:
Mutualism: individuals of both species benefit from service or resource one provides another Cleaners remove dead skin and ectoparasites from other fish species ‘Host’ fish loses its parasites; cleaner fish gains a meal
Answer: Trees provide a safe nesting site for many bird species. Options 1, 2 and 4 are examples of mutualism, as both species benefit from the interaction. This is not true of option 3, as trees usually receive no benefit from allowing birds to nest in them. This arrangement (in which only one species benefits, but at zero expense to the other) is known as commensalism rather than mutualism.
The problem of free riders A community of bacterial cells
Communal cells produce beneficial products shared between all cells
The problem of free riders A community of bacterial cells Free rider cells don’t produce communal products
The problem of free riders A community of bacterial cells
But still benefit from the products of other cells
The Prisoner’s Dilemma Prisoner B
Prisoner A
Cooperate
Defect
Cooperate
Defect
Mutual cooperation rewarded = both receive 1 year in prison
Prisoner B gets freedom
Prisoner A gets freedom
Mutual defection punished = both receive 5 years in prison
Prisoner B gets 10 years in prison
Prisoner A gets 10 years in prison
Summary Cooperation can take on varied forms, within and between species as diverse as fish and bacteria Cooperators are vulnerable to exploitation by free-riders Prisoner’s dilemma game illustrates why cooperation is often not evolutionarily stable
PDF Citations Slide 1 _MG_2581 peacock spider Maratus volans by Jurgen Otto (http://www.flickr.com/photos/59431731@N05/5521738809/). Reproduced with permission from Jurgen Otto. Slide 3 a) "Struthidea cinerea group" (http://commons.wikimedia.org/wiki/File%3AStruthidea_cinerea_group.jpg) by David Woodward (Own work) (CC BY-SA 3.0), via Wikimedia Commons b) "Banded mongoose arp" (http://commons.wikimedia.org/wiki/File:Banded_mongoose_arp.jpg) by Adrian Pingstone (Own work) [Public Domain], via Wikimedia Commons Slides 4 & 5 a) "Carrion Crow Corvus corone" (http://commons.wikimedia.org/wiki/File:Carrion_Crow_Corvus_corone.jpg) by Richard Bartz (CC BY-SA 2.5) via Wikimedia Commons b) Graphs by Milly Formby based on data from (Canestrari, D. , Marcos, J. M & Baglione, V.) Reproductive success increases with group size in cooperative carrion crows, Corvus corone corone. Animal Behaviour. 75:2 (2008) pp. 403-416. Elsevier. Slide 6 a) " Superb fairy wrens mark 2 " (https://ha.m.wikipedia.org/wiki/File:Superb_fairy_wrens_mark_2.jpg) by benjamint444 (Own work) (CC BY-SA 3.0), via Wikimedia Commons b) Graphs by Milly Formby based on data from (Russell, A. F, Langmore, N. E., Cockburn, A., Astheimer, L. B. & Kilner, R. M) Reduced Egg Investment Can Conceal Helper Effects in Cooperatively Breeding Birds. Science. Vol. 317 (2007) pp. 941 – 945. Slide 7 Vibrio Cells 1 (http://www.flickr.com/photos/adonofrio/5390287631/) by Anthony D’Onofrio. Image courtesy of the Lewis Lab at Northeastern University. Image created by Anthony D'Onofrio, William H. Fowle, Eric J. Stewart and Kim Lewis (CC BY 2.0)
Slide 8 a) "Sweetlips wrasse" (http://commons.wikimedia.org/wiki/File%3ASweetlips_wrasse_Nick_Hobgood.jpg) by Nick Hobgood (Own work) (CC BY-SA 3.0), via Wikimedia Commons b) "Honeycomb Moray gets cleaned by Shrimp" (http://www.flickr.com/photos/37707866@N00/7597017388/) by Silke Baron (CC BY 2.0) Slides 10-12 Bacterial cells by Milly Formby (C) University of Melbourne Slide 13 Prisoner’s Dilemma diagrams by Raoul Mulder Based on concepts expressed in (Axelrod, R & Hamilton, W. D.) The Evolution of Cooperation. Science, New Series. 211:4489 (1981) pp. 1390-1396
Cooperation I
What is cooperation? A behaviour is cooperative if … i) it provides a benefit to another individual (i.e. the recipient) AND ii) has been selected for because of its beneficial effect on the recipient
Cooperatively breeding vertebrates Example 1:
Dominant breeding pair + subordinate ‘helpers’
Apostlebirds
Subordinates may be nondispersing young from previous breeding attempt, or immigrants Feed and protect young, other members of the group
Banded mongoose
Benefits: improved breeding success 1.2 66
242 162
0
2
3
4
>4
No. of individuals in the group
Breeding success as a proportion of group size
118
No. of fledglings
Carrion crow Corvus corone
0.46 134
75
4
>4
225 173
0.32
2
3
No. of individuals in the group
Benefits: improved breeding success 1.2 66
242 162
0
2
3
4
>4
No. of individuals in the group
Breeding success as a proportion of group size
118
No. of fledglings
Carrion crow Corvus corone
0.46 134
75
4
>4
225 173
0.32
2
3
No. of individuals in the group
Carrion crow groups with helpers breed more often and produce more fledglings
reduced workload Benefits: improved survival 1350
Mean weight of offspring (g)
Mean volume of eggs (mm3)
10
Fairy-wren helpers don’t increase reproductive success ... ... but they allow females to lay smaller eggs, which leads to improved female survival
Pair without help
Pair with help
5
Pair without help
1.0
Probability of surviving
1150
0.5
Pair without help
Pair with help
Pair with help
Cooperative bacteria Example 2:
Production of iron-scavening molecules ‘siderophores’ Vibro tasmaniensis bacterial cells with siderophores
Cooperative ‘slime cities’ in dental plaque and sink plugholes
Siderophores released into extra-cellular space; sequester iron Other bacterial cells benefit from access to ‘public goods’
Cleaner fish mutualisms Example 3:
Mutualism: individuals of both species benefit from service or resource one provides another Cleaners remove dead skin and ectoparasites from other fish species ‘Host’ fish loses its parasites; cleaner fish gains a meal
Answer: Trees provide a safe nesting site for many bird species. Options 1, 2 and 4 are examples of mutualism, as both species benefit from the interaction. This is not true of option 3, as trees usually receive no benefit from allowing birds to nest in them. This arrangement (in which only one species benefits, but at zero expense to the other) is known as commensalism rather than mutualism.
The problem of free riders A community of bacterial cells
Communal cells produce beneficial products shared between all cells
The problem of free riders A community of bacterial cells Free rider cells don’t produce communal products
The problem of free riders A community of bacterial cells
But still benefit from the products of other cells
The Prisoner’s Dilemma Prisoner B
Prisoner A
Cooperate
Defect
Cooperate
Defect
Mutual cooperation rewarded = both receive 1 year in prison
Prisoner B gets freedom
Prisoner A gets freedom
Mutual defection punished = both receive 5 years in prison
Prisoner B gets 10 years in prison
Prisoner A gets 10 years in prison
Summary Cooperation can take on varied forms, within and between species as diverse as fish and bacteria Cooperators are vulnerable to exploitation by free-riders Prisoner’s dilemma game illustrates why cooperation is often not evolutionarily stable
PDF Citations Slide 1 _MG_2581 peacock spider Maratus volans by Jurgen Otto (http://www.flickr.com/photos/59431731@N05/5521738809/). Reproduced with permission from Jurgen Otto. Slide 3 a) "Struthidea cinerea group" (http://commons.wikimedia.org/wiki/File%3AStruthidea_cinerea_group.jpg) by David Woodward (Own work) (CC BY-SA 3.0), via Wikimedia Commons b) "Banded mongoose arp" (http://commons.wikimedia.org/wiki/File:Banded_mongoose_arp.jpg) by Adrian Pingstone (Own work) [Public Domain], via Wikimedia Commons Slides 4 & 5 a) "Carrion Crow Corvus corone" (http://commons.wikimedia.org/wiki/File:Carrion_Crow_Corvus_corone.jpg) by Richard Bartz (CC BY-SA 2.5) via Wikimedia Commons b) Graphs by Milly Formby based on data from (Canestrari, D. , Marcos, J. M & Baglione, V.) Reproductive success increases with group size in cooperative carrion crows, Corvus corone corone. Animal Behaviour. 75:2 (2008) pp. 403-416. Elsevier. Slide 6 a) " Superb fairy wrens mark 2 " (https://ha.m.wikipedia.org/wiki/File:Superb_fairy_wrens_mark_2.jpg) by benjamint444 (Own work) (CC BY-SA 3.0), via Wikimedia Commons b) Graphs by Milly Formby based on data from (Russell, A. F, Langmore, N. E., Cockburn, A., Astheimer, L. B. & Kilner, R. M) Reduced Egg Investment Can Conceal Helper Effects in Cooperatively Breeding Birds. Science. Vol. 317 (2007) pp. 941 – 945. Slide 7 Vibrio Cells 1 (http://www.flickr.com/photos/adonofrio/5390287631/) by Anthony D’Onofrio. Image courtesy of the Lewis Lab at Northeastern University. Image created by Anthony D'Onofrio, William H. Fowle, Eric J. Stewart and Kim Lewis (CC BY 2.0)
Slide 8 a) "Sweetlips wrasse" (http://commons.wikimedia.org/wiki/File%3ASweetlips_wrasse_Nick_Hobgood.jpg) by Nick Hobgood (Own work) (CC BY-SA 3.0), via Wikimedia Commons b) "Honeycomb Moray gets cleaned by Shrimp" (http://www.flickr.com/photos/37707866@N00/7597017388/) by Silke Baron (CC BY 2.0) Slides 10-12 Bacterial cells by Milly Formby (C) University of Melbourne Slide 13 Prisoner’s Dilemma diagrams by Raoul Mulder Based on concepts expressed in (Axelrod, R & Hamilton, W. D.) The Evolution of Cooperation. Science, New Series. 211:4489 (1981) pp. 1390-1396
