There were errors in the Author Contributions section. The correct contributions are: Conceived and designed the experiments: WS JF. Performed the experiments: WS. Analyzed the data: WS. Interpreted the data: JF. Designed the simulations: CK WL. Performed and analyzed the simulations: CK. Wrote the paper: WS CK JF.
Footnotes
Competing Interests: No competing interests declared.
