Nearly ten thousand years ago, when humans were just learning to save and re-plant seeds, some tribes in Central Asia started taking care of the plant that would turn out to be the ancestor of today’s cannabis. Cannabis can be used for lots of different things, and we don’t know which of these uses came first. In any case, it was useful. So useful, in fact, that humans eventually brought it with them to every corner of the earth.

In each place, this Swiss-army-knife-of-a-plant began to adapt and specialize. Hemp varieties emerged in Europe and Eastern China. Many thousands of years ago, varieties with high levels of psychoactive THC were already widespread in the Near East and Western China. It reached South America in the 1500s with the Spanish conquistadors, in the first of what would be several waves of cannabis emigration to the New World. In fact, for many centuries, sailors would never begin a long ocean voyage without some hemp seeds aboard — so that, if they were stranded on a deserted island, they would be able to regrow their own sails, and escape.

Eventually the varietals in each location would differentiate into what we call landraces — local plant varieties nurtured year after year by farmers who saved the best seeds for the next season’s planting. Then, beginning in the 1960s, all of these varieties met again in California and Holland, where they were cross-bred into a seriously tangled web of genetics. A polyhybrid swarm. A melting pot.

This is both good and bad. Fifty years of active underground cannabis breeding has diversified dozens of varieties into thousands. It’s made the plant a vehicle for extraordinary amounts of cannabinoids and terpenes, and created a psychedelic swirl of colors and flavors that can make grow-rooms look more like a Ben and Jerry’s than a farm. It also kept alive the basic raw enthusiasm that has turned an illegal enterprise into the fastest-growing industry in the country, and a ropy weed into a cure for thousands of children with epilepsy.

Hybridization mixes genes into new combinations, and some of these new combinations have been game-changing. But it can also take useful combinations that have evolved over millennia, and split them up. The legendary landrace and first-generation cannabis hybrids were incredible — in ways you don’t see anymore. Some had insect or mold-resistance traits that are now rare or nonexistent. Many produced a type of euphoric high that’s hard to find today. Some of these traits probably relied on combinations that were wiped out with the influx, in the 1970s, of Afghan genes for high yield and low stature — the genes that powered the basement economy we had for so long.

Cannabis is the most genetically diverse plant in the world, and it’s also the most hybridized. This means that many of the genes that have existed throughout history might be in your local dispensary, but the historical combinations of genes are gone. The diversity that’s there means that anything is still possible with this plant. But there’s a lot of work to do if we’re going to see its full potential. If that work is going to get done, we have to make sure that all of those important genes are preserved.

The cannabis industry could easily become a THC production industry, where Big Ag companies use monoculture farming techniques to grow whatever variety is the highest-yielding, churning out tons of 99% THC oil for vape pens and pharma companies. Or — we could protect the diversity that’s out there, and cannabis could become an industry like wine, hops, or coffee, where careful breeding and craft manufacturing create an endless variety of products that are interesting, tasty, and (in this case) medically invaluable.