Gorilla population surveys, conducted by the Wildlife Conservation Society, have helped the government of Cameroon create a new national park which will protect more than 600 gorillas, along with other threatened species such as chimpanzees, forest elephants, buffaloes, and bongo.

It's a 500-pound gorilla that Robert Criss, Ph.D., professor of earth and planetary sciences in Arts & Sciences at Washington University in St. Louis, sees standing on the speaker's dais at political rallies, debates and campaigns. Its name is population growth.