emulate v.

"effort to equal or excel in qualities or actions that one admires in another or others; imitative rivalry," 1550s, from French émulation (13c.) and directly from Latin aemulationem (nominative aemulatio) "rivalry, emulation, competition," noun of action from past-participle stem of aemulari "to rival, strive to excel," from aemulus "striving, rivaling" (also as a noun, "a rival," fem. aemula), from Proto-Italic *aimo-, from PIE *aim-olo, suffixed form of root *aim- "copy" (from PIE root *aim- "to copy").

Proto-Indo-European root meaning "to copy." 

It forms all or part of: emulate; emulation; emulous;  image; imaginary; imagination; imaginative; imagine; imago; imitable; imitate; imitative; imitator; inimitable.

It is the hypothetical source of/evidence for its existence is provided by: Latin imago "image," aemulus "emulous," imitari "to copy, portray, imitate;" Hittite himma- "imitation, substitute."