Extinction by Hybridization

Hybridization is the main cause of extinction and biodiversity loss in Cannabis.

Indigenous Asian populations hold the vast majority of Cannabis biodiversity.

For “drug-type” Cannabis (aka, subsp. indica) that particularly means the wild-types, var. himalayensis and var. asperrima, which have an exceptionally broad genetic base.

Bringing foreign seed to ancient centres of biodiversity such as India or Cambodia has set in motion an irreversible process known as genetic swamping. This is when regional genotypes are replaced by hybrids, permanently annihilating millennia of irreplaceable genetic diversity.

In post-Hippie Trail South and Southeast Asia, this mostly involved Westerners introducing Indicas (var. afghanica). The technical term for the resulting ecological nightmareas it is in the context of indigenous Cannabisis introgressive hybridization.

The rise of Internet commerce means that process has rapidly accelerated, with an unprecedented influx of hybrid seed to countries such as India and Pakistan. Compared to traditional Asian domesticates (“landraces”) and wild-growing plants, these modern IndicaSativa hybrids are genetically narrow and homogeneous.

Short-sighted and uncontrolled hybridization is not merely a catastrophe for Cannabis itself but also destroys the heritage and wealth of impoverished farming communities and their nations. Without real landraces there can’t be real Nepali charas or Thai ganja, for example. Lost too is the possibility of a multitude of future indigenous cultivarscures and creations which we haven’t even begun to conceive of yet.

Here’s an important and freely available ecological study by Judith Rhymer and Daniel Simberloff, Extinction by Hybridization and Introgression. A key focus of the paper is loss of biodiversity by hybridization within a single species, as now threatens the future of Cannabis.

For a recent overview of hybridization and extinction, including genetic swamping, see this talk by renowned professor of botany and plant evolutionary genomics, Loren Rieseberg:

5 responses to “Extinction by Hybridization

  1. TRSC, is doing more to help this than any other group I’m aware of.
    While marketing pheno hunting has been successful for pollen chucking. It is devastating our landrace and farm / village grown cannabis. Dispensary hype has nothing to do with quality of buds.
    Consumer knowledge and the desire for a better product has to be understood. Not a single old-school legend is a hybrid of a hybrid of a hybrid. If it doesn’t sell change the name. If we don’t have it sell them anything and say you’re getting the last we have of that strain.
    There’s nothing on the market today that is worth half of what you’re paying for the hype.
    Demand better!

  2. I Iive on the U.S. and Mexico border in the state of Texas. I have grown many landraces from Mexico, here at 30 degrees latitude, and have also grown many modern hybrids and Afghanica plants outside here. Without supplemental lighting, Afghanicas, and hybrids of it, begin to flower within 4 weeks of germination from seed, even during the Summer Solstice, because our longest day is only 14 hrs. Those types of plants are only a foot or two tall when they finish flowering and yield very little Bud. For that reason I only grow landrace Mexicans that I have had since the 1980’s. Why would a subtropical or equatorial country import Hybrid seed to grow when they won’t produce a fraction of what their own landrace “Sativas” will produce? I have heard for years that Mexican landraces have all been replaced by Hybrids. I have yet to see any evidence of that and I look at imported brickweed regularly. It just doesnt make any sense that a drug organization would want to switch to growing a plant that produces less, not to mention the mold and fungal issues Hybrids have in a humid environment. It seems to me that, for the reasons I’ve mentioned, hybrid plants are really only suitable to grow outdoors in higher latitude areas like Europe and North America, not in subtropical or equatorial parts of the world.

    • hi Kenneth, thanks for commenting.

      A lot of the discussion of the situation with Cannabis outside America, Canada, and Europe, even among academics and ostensible experts, is based on hearsay and second- and third-hand information. I don’t know of a single Cannabis expert who has published on the Hindu Kush who has even been there, for example. That includes Rob Clarke, who’s written a whole book on hashish and apparently isn’t aware that the main name for hashish in Afghanistan and Pakistan is in fact charas (“chars”).

      Never having been to Mexico, I don’t make a habit of commenting on it with respect to the landrace situation. That said, the Mexican import I saw in California in 1996 was certainly a hybridized landrace. I saw the same type of hybridized landraces sold as Mexican and Colombian in the early 2000s in Amsterdam. Right now, we’re growing out some seeds we collected from Colombia in the early 1990s, and they’re certainly hybridized landraces too.

      In the UK, by the early 2000s, the authentic Caribbean landrace imports from Jamaica (which we saw up till the late 90s) rapidly switched to hybrids and hybridized landraces. Whereas in the early 1990s, when I was in Guyana and the Caribbean, everything I saw was authentic landrace ganja, with the exception of some bud sold as “Chronic” in Kingston.

      I totally agree that it’s bad news for farmers in the tropics to grow most Western hybrids, not least given how Indica-heavy most are. But many farmers certainly are growing hybrids and/or hybridized landraces. The more Western influence there is an area, the worse the situation gets. After several visits to Cambodia over a decade now, the only genuine landrace I found was in the Northwest, way off the tourist trail. Everything else I have seen there was either a Western hybrid or a mongrelized landrace-hybrid cross.

  3. Pingback: Endangered Varieties of subsp. indica: A Few Thoughts | The Real Seed Company: The Honest Online Source for Cannabis Landraces Founded 2007·

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