In celebrating of the bi-centenary of Darwin's birth, Journal of Animal Ecology, which is founded in 1930 and now is one of the flagship journals of ecological society, compiled a virtual issue of some of the exciting works showing the links between ecology and evolution. These selected papers have made a major impact on the way we think. The paper of Dr Rui-Wu Wang et al. published in 2008 was selected as one of these 20 papers.

The paper of Rui-Wu Wang et al. demonstrated that cooperative equilibrium or evolutionary stable strategy (ESS) might not exist in the cooperation systems. Using the fig-fig wasp mutualism as model systems, Rui-Wu Wang experimentally showed that self-restraint or the spatial heterogeneity can not sufficiently maintain the stable cooperation interaction between figs and fig wasps. The cooperation interaction between figs and fig wasps will transform to conflict interaction after the common resource utilization saturated. The fig-fig wasp mutualism presented that cooperation interaction will occur when the common resource is plentiful but a conflict interaction when the common resource is limited.

The paper of Rui-Wu Wang et al. also demonstrated, exampled with fig-fig wasp mutualism, that the previous arguments on whether the cooperation system essentially is cooperation interaction or conflict interaction might result from the unreasonable data analysis or abuse of linear regression and generalized linear regression.

This is the second published paper of Rui-Wu Wang et al that is recommended by one of most well known international organization, after the PLOS one paper was recommended as one of important discovery by Faculty of 1000 Biology in early of 2010.

The recommended paper: Rui-Wu Wang，Lei Shi,Shi Meng Ai, Qi Zheng. 2008. Trade-off between the reciprocal mutualists: local resource availability oriented interaction in fig/fig wasp mutualism. Journal of Animal Ecology. 77, 616-623.