Assertion: vestigial structure | /r/HasProperty | useless
Facets:
value: for its primary function
type: CAUSE
Source sentences:
text: Darwin also noted, in On the Origin of Species, that a vestigial structure could be useless for its primary function, but still retain secondary anatomical roles: "An organ serving for two purposes, may become rudimentary or utterly aborted for one, even the more important purpose, and remain perfectly efficient for the other....