Since its inception in 1971, Pilobolus dance theater has existed outside of the box. For starters, it was formed by a group of Dartmouth College students with no dance training. Possessing a strong commitment to collaboration, the troupe crosses creative disciplines in its quest for new forms of expression — and it has reaped rewards. Among other accolades, the company has earned a Grammy Award nomination, a TED fellowship and a Dance Magazine Award as well as spots on popular TV programs such as “Ellen” and “60 Minutes.” The dancers bring a blend of artistry, athleticism and drama to the Barre Opera House with a program that includes the stirring piece “On the Nature of Things.”