ecology (n.) Look up ecology at Dictionary.com
1873, oecology, "branch of science dealing with the relationship of living things to their environments," coined in German by German zoologist Ernst Haeckel (1834-1919) as Ökologie, from Greek oikos "house, dwelling place, habitation" (from PIE root *weik- (1) "clan") + -logia "study of" (see -logy). In use with reference to anti-pollution activities from 1960s.