Whatever the mechanism, though, this study provides what no previous study ever has: evidence from a controlled experiment that keystone species really exist.

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Its authors, Steffen Huck and Brian Wallace of University College London (UCL), and Charlotte Duke of London Economics, a consultancy, base that finding on a controlled experiment.

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Amoruso also tried a controlled experiment.

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Indeed, it is why many early medical advances became standard of care without anyone seeing the need for a placebo controlled experiment.

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To further study the reasons behind the findings, the researchers conducted a similar experiment in the controlled environment of a university lab.

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Indeed, America is conducting a national experiment regarding capitalism versus socialism between these 25 Republican controlled states, and the 15 states with Democrat Governors and Democrat controlled state legislatures: California, Oregon, Washington, Hawaii, Colorado, Minnesota, Illinois, West Virginia, Maryland, Delaware, New York, Connecticut, Rhode Island, Massachusetts, and Vermont.

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