Sativa & Indica Origins + Genetics
Scientists that have studied the differences between indica and sativa have come up with a number of theories based on genetics. One prevailing theory focuses on the genetic production of THC and CBD.
Plants that produce high levels of THC express genes that code for the enzyme THCA synthase. This enzyme converts CBG into THCA, which becomes THC when heated. These plants are typically considered indica.
On the other hand, some plants express genes that code for the enzyme CBDA synthase. This enzyme converts CBG into CBDA, the precursor of CBD, instead. These plants are typically considered sativa.
Based on this explanation, indica plants have high THC:CBD ratios and sativa plants have high.