How marking genomes impacts our understanding and utilization of cannabis varieties.
When you ask people who their favorite superhero is, they might say Iron man, Wonder Woman, The Hulk, or Batman.
Those people are all cool, but that’s not my answer. My answer is a pair of superheroes: Watson and Crick!
Never heard of them? They were more popular in the 1950s and 1960s, to be sure. Today, we take their talents for granted. What were they known for? They were able to see things that no one else could. They understood life better than any person before, and they won a Nobel Prize for it in 1962.
Of course, you probably realize that Watson and Crick were not muscular beasts that could fly and stop bullets with their bare hands. No, they were the pair of scientists who discovered the double helix, the molecular structure of our deoxyribonucleic acid, or DNA. Consider me a fanboy.
Without the basis of genetic science, we wouldn’t be able to know as much as we know about Cannabis. Researchers have lambasted the industry’s tendency to switch names of cultivars simply to generate revenue. But now, the industry is changing and basing its knowledge on the genetic differences between plants, not the lucrative name-changing game.
The science behind the genetic blueprint of specific cannabis cultivars is quite interesting. For starters, it seems that hemp is more closely related to chemovars indicative of what we commonly call“indicas” than it is to plants labeled as“sativas”. 
Beyond that, however, is how microsatellites – sections of repetitive DNA – are helping scientists determine the lineage of cannabis cultivars. Microsatellites are used for studying genetic lineages by identifying repeat nucleotide sequences and ‘marking’ them to map out that plant’s lineage. This is done in forensic science to help trace seized cargo to its origin. 
There are also uses for microsatellites in the cannabis industry. For example, using this type of genetic identification, growers can better understand their plants, how to grow them, and how to breed for specific traits.
Interestingly, and perhaps expectedly, researchers discovered that there is more diversity in drug-type cultivars as compared to hemp varieties. A 2015 paper indicated that
The more researchers are able to identify genomic markers on all cannabis varieties, the more they will be able to identify chemovars, understand their lineage, and breed novel varieties.
- Sawler, J. et al. ‘The Genetic Structure of Marijuana and Hemp.” PLOS ONE, 2015; 10(8). [Times Cited = 69, Journal Impact Factor = 2.766].
- Dufresnes C. et al., “Broad-Scale Genetic Diversity of Cannabis for Forensic Applications.” PLOS ONE, 2017; 12(1).[Times Cited = 6, Journal Impact Factor = 2.766]
- Lynch, R., et al., “Genomic and Chemical Diversity in Cannabis”, Critical Reviews in Plant Sciences, 2016, 35(5-6): 349-363. [Times Cited = 17, Journal Impact Factor = 6.162]