Ecologists study the connections living things have with one another and their surroundings. John Woodward did some of the first ecology experiments in 1699 and figured out algae bloom. Aldo Leopold’s work led to the Endangered Species Act to protect plants and animals from becoming extinct, and he led the U.S. government to begin considering the environmental impact of land use. Eugene Odum was the first to see Earth as a set of interlocking ecosystems. His work led to laws to protect wetlands.