There is not single "Creative Commons" license. The project allows you to pick the attributes you want, and then gives you a license that covers them. In the case of the PLoF, they have only chosen to require attribution. A summary of their license is here: http://www.plos.org/journals/license . It allows modifications for any purpose, and since they have not opted for a copyleft clause, derivative works can be released under any license, including the GFDL.
That said, we still probably won't be able to include much. PLoS publishes journals, and journals publish new research. As an encyclopedia, it is beyond our scope to publish research that has not yet gone through extensive peer review.
Stephen G.
The article I did, What Controls Variation in Human Skin Color, was more a summary of other research than original research.
Fred