Cannabis is believed to have evolved from its closest cousin, humulus (hops). Although the origins of cannabis are not clearly understood, it is believed that it diverged from humulus approximately 27.8 million years ago! Recent research and archaeological finds have indicated that cannabis was first domesticated in early Neolithic times, approximately 12,000 years ago (or 10,000 B.C.) in eastern Asia (China.)
Researchers believe that it was cultivated for its fiber for thousands of years before it was selectively bred for medicinal purposes. The first evidence of the divergence of marijuana and hemp from the family cannabiceae appears to be around 4,000 years ago, or 2,000 B.C. taller, woodier plants (hemp) were cultivated for the fiber and shorter more floral plants (marijuana) were produced for medicinal purposes.