CBD: THC Ratios
The problem is that, today, many strains produce varying amounts of both enzymes. Some researchers believe this is due to hybridization of the gene pools, which explains why some sativas are rich in THC and some indicas are not.
An alternate theory based on geographic origin has also been proposed. A common Cannabis species is thought to have originated from central Asia before separating into distinct sativa and indica gene pools.
Recent attempts to distinguish sativa verses indica have relied on a combination of geographical and genetic theories. The existence of a few rare species, such as Cannabis ruderalis, has been suggested but much about them remains unknown.