TY - JOUR
T1 - Asymmetric interaction and indeterminate fitness correlation between cooperative partners in the fig-fig wasp mutualism
AU - Wang, Rui Wu
AU - Sun, Bao Fa
AU - Zheng, Qi
AU - Shi, Lei
AU - ZHU, Lixing
N1 - Funding information:
We are indebted to Christopher X. J. Jensen, Douglas W. Yu and two anonymous reviewers for the extensive language revision, comments and revision suggestions of the draft of manuscript, to Robert May for his kind reading of this manuscript and encouragement to authors before this submission. We also thank for Stuart A West, Finn Kjellberg, Stephen Compton and Ford R. Denison for their extensive discussions and revision suggestions of this manuscript, and to Yan Luo and Ting Zhou for their contribution to data collection. We thank the Xishuangbanna Tropical Botanical Garden for permission to work in their grounds. This research was supported by the National Basic Research Programme of China (2007CB411600), National Natural Science Foundation of China (30670272, 30770500, 10761010), the Yunnan Natural Science Foundation (2009CD104), the West Light Foundation of the Chinese Academy of Sciences, Special Fund for the Excellent Youth of the Chinese Academy of Sciences (KSCX2-EW-Q-9), the National Social Science Foundation of China (08XTJ001), State Key Laboratory of Genetic Resources and Evolution, and Research Grants Council of Hong Kong (HKBU2030/07P). Professors Ya-Ping Zhang and Jun-Xing Yang financially supported this research.
PY - 2011/10/7
Y1 - 2011/10/7
N2 - Empirical observations have shown that cooperative partners can compete for common resources, but what factors determine whether partners cooperate or compete remain unclear. Using the reciprocal fig-fig wasp mutualism, we show that nonlinear amplification of interference competition between fig wasps - which limits the fig wasps' ability to use a common resource (i.e. female flowers) - keeps the common resource unsaturated, making cooperation locally stable. When interference competition was manually prevented, the fitness correlation between figs and fig wasps went from positive to negative. This indicates that genetic relatedness or reciprocal exchange between cooperative players, which could create spatial heterogeneity or self-restraint, was not sufficient to maintain stable cooperation. Moreover, our analysis of field-collected data shows that the fitness correlation between cooperative partners varies stochastically, and that the mainly positive fitness correlation observed during the warm season shifts to a negative correlation during the cold season owing to an increase in the initial oviposition efficiency of each fig wasp. This implies that the discriminative sanction of less-cooperative wasps (i.e. by decreasing the egg deposition efficiency per fig wasp) but reward to cooperative wasps by fig, a control of the initial value, will facilitate a stable mutualism. Our finding that asymmetric interaction leading to an indeterminate fitness interaction between symbiont (i.e. cooperative actors) and host (i.e. recipient) has the potential to explain why conflict has been empirically observed in both well-documented intraspecific and interspecific cooperation systems.
AB - Empirical observations have shown that cooperative partners can compete for common resources, but what factors determine whether partners cooperate or compete remain unclear. Using the reciprocal fig-fig wasp mutualism, we show that nonlinear amplification of interference competition between fig wasps - which limits the fig wasps' ability to use a common resource (i.e. female flowers) - keeps the common resource unsaturated, making cooperation locally stable. When interference competition was manually prevented, the fitness correlation between figs and fig wasps went from positive to negative. This indicates that genetic relatedness or reciprocal exchange between cooperative players, which could create spatial heterogeneity or self-restraint, was not sufficient to maintain stable cooperation. Moreover, our analysis of field-collected data shows that the fitness correlation between cooperative partners varies stochastically, and that the mainly positive fitness correlation observed during the warm season shifts to a negative correlation during the cold season owing to an increase in the initial oviposition efficiency of each fig wasp. This implies that the discriminative sanction of less-cooperative wasps (i.e. by decreasing the egg deposition efficiency per fig wasp) but reward to cooperative wasps by fig, a control of the initial value, will facilitate a stable mutualism. Our finding that asymmetric interaction leading to an indeterminate fitness interaction between symbiont (i.e. cooperative actors) and host (i.e. recipient) has the potential to explain why conflict has been empirically observed in both well-documented intraspecific and interspecific cooperation systems.
KW - Asymmetric cooperation
KW - Chaotic oscillation
KW - Fig-fig wasp
KW - Interference competition
KW - Mutualism
KW - Tragedy of the commons
UR - http://www.scopus.com/inward/record.url?scp=79961134910&partnerID=8YFLogxK
U2 - 10.1098/rsif.2011.0063
DO - 10.1098/rsif.2011.0063
M3 - Journal article
AN - SCOPUS:79961134910
SN - 1742-5689
VL - 8
SP - 1487
EP - 1496
JO - Journal of the Royal Society Interface
JF - Journal of the Royal Society Interface
IS - 63
ER -