When Something Serves a Purpose
If to be a "something" is to have a place in the scheme of things (once we've assumed there are schemata to be had), then the consistency with which that something may take its place will signify that being in such a place predictively amounts to at least one purpose (if not the greater purpose) that this something serves., i.e., its schematic need to take that time and place in nature.
Purposes to which these somethings are put? Not necessarily.
Found to fit? More likely.