data_preliminary_experiment: Parasite size and effect of parasite number on an intraspecific conflict

Data for supplementary results 2. Worksheet 1 ("copepods") contains information on each copepod used in the study including dead or incorrectly infected copepods. Worksheet 2 ("behavior") contains the behavior of only those copepods that survived until their infection status could be determined and that were infected by all parasites they had been exposed to. No behavior was recorded for any of the other copepods. The behavior consists of the position of each copepod every two seconds during one minute after a simulated predation attack and after a recovery period and, resulting from this whether or how far they moved during this time interval. This data was obtained from video recordings of copepod behavior using the manual tracking tool in imageJ and was done blindly as to the infection status of each copepod

data_experiment1: intraspecific conflict and cooperation

Worksheet 1 ("copepods") contains information on each copepod used in the study including dead or incorrectly infected copepods. Worksheet 2 ("behavior") contains the behavior of only those copepods that survived until their infection status could be determined and that were infected by all parasites they had been exposed to. No behavior was recorded for any of the other copepods. The behavior consists of the position of each copepod every two seconds during one minute after a simulated predation attack and after a recovery period and, resulting from this whether or how far they moved during this time interval. This data was obtained from video recordings of copepod behavior using the manual tracking tool in imageJ and was done blindly as to the infection status of each copepod

data_experiment_2

basic data: Data on each copepod used in the experiment. latency: results for each copepod on each day for how long it took to resume moving after a simulated predator attack. Behavioral data: Data on the position of each copepod during each two second interval and whather or not it moved for all days on which behavior was recorde

data_experiment2_effect_of_parasite_number_on_intraspecific_conflict

Worksheet 1 ("copepods") contains information on each copepod used in the study including dead or incorrectly infected copepods. Worksheet 2 ("behavior") contains the behavior of only those copepods that survived until their infection status could be determined and that were infected by all parasites they had been exposed to. No behavior was recorded for any of the other copepods. The behavior consists of the position of each copepod every two seconds during one minute after a simulated predation attack and after a recovery period and, resulting from this whether or how far they moved during this time interval. This data was obtained from video recordings of copepod behavior using the manual tracking tool in imageJ and was done blindly as to the infection status of each copepod

data_experiment_1

basic data: Data on each copepod used in the experiment. latency: results for each copepod on each day for how long it took to resume moving after a simulated predator attack. Behavioral data: Data on the position of each copepod during each two second interval and whather or not it moved for all days on which behavior was recorde

In the treatment with replacement, double players benefit from being extortionate.

<p>The graph shows cooperation rates (<b>A</b>) and payoffs (<b>B</b>) in the treatment with replacement, depending on whether the double player was classified as extortionate or not. Error bars represent standard errors. Extortionate players were less cooperative than non-extortionate players; nevertheless they received more cooperation from their respective co-players. As a result, extortionate double players outperformed both their direct co-players and non-extortionate double players.</p

Extortioners incentivize their co-players to cooperate, and they obtain an excessive share of the resulting payoffs.

<p>For groups with an extortionate double player in the treatment with replacement, the graph shows how both the single and the double players’ payoffs depend on the single player’s cooperation rate. Each dot corresponds to an outcome of a 10-round block, across the 13 extortionate groups; the two lines represent linear regression curves. Extortioners adopt a strategy such that single players benefit from increasing their cooperation rate within each 10-round block (as the blue line has a positive slope). The more cooperative single players are, the higher is the share of total payoffs that goes to the extortioner (as the distance between the two lines becomes maximal when the single players’ cooperation rate approaches 100%).</p

Overview of the experimental setup.

<p>Players interact in a repeated prisoner’s dilemma over 60 rounds. In each round they choose between the option C (corresponding to cooperation) and the option D (referring to defection). Payoffs are taken from Axelrod [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0163867#pone.0163867.ref016" target="_blank">16</a>]: mutual cooperation yields the reward <i>R</i> = € 0.30 for both players, whereas mutual defection gives the punishment payoff <i>P</i> = € 0.10; if only one player cooperated, the cooperator receives the sucker’s payoff <i>S</i> = € 0.00 and the defector receives the temptation <i>T</i> = € 0.50. Both treatments have in common that the game is asymmetric, as double players have twice as many interactions as single players. But the second treatment adds another source of asymmetry, as only double players have the option to replace one of their co-players by the inactive player. The rules of the game, as well as the strategic options of each player were commonly known (except that subjects were not aware of the exact length of the game). In addition, each subject was informed about the decisions of all other group members after each round. For the statistical analysis we considered groups of players as our statistical unit, and we used non-parametric and two-tailed tests throughout. To compare double players with single players, we pooled the decisions of all active single players within a group. Moreover, as double players had more interactions than single players, we considered payoffs per interaction (unless stated otherwise). For the treatment with replacement, the reported total earnings for single players give the average over all three single players (including the inactive player). For details, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0163867#sec007" target="_blank">Methods</a>.</p

Players earn significantly more when they are allowed to replace group members.

<p>The four panels show average payoffs (<b>A</b> and <b>B</b>) and the overall distribution of payoffs (<b>C</b> and <b>D</b>) across the two treatments. (<b>A</b>) Already without replacement, double players earn more than single players (error bars represent standard errors). (<b>B</b>) This payoff advantage becomes even more distinct when the replacement option is available. (<b>C</b>,<b>D</b>) In the treatment without replacement, groups are clustered around the main diagonal (indicating relatively equal payoffs), whereas in the treatment with replacement, groups are more scattered (indicating considerable payoff differences within some groups).</p

Outcome of Sperm Competition Trials

Outcome of Sperm Competition Trial