E ecological- the pattern of relations between organisms and their environment edibles- fit to be eaten eerie- strange, mysterious, perhaps scary efficiency- producing results without wasted energy or effort effigy- an image especially of a person elapsed- the passing of a period of time embankment- a mound of earth used to hold back water environment- conditions that surround an individual or a community epidemics- outbreaks of disease that make many people in an area sick at the same time epoch- a long period of time with distinctive characteristics, a division of geological time excavation- remove or uncover by digging exceptionally- unusual, not ordinary exploit- to use for an economic purpose extinct- no longer alive or existing