Originally Posted by Jhhnn
I think you're right. Specimens within a population will self select on the basis of their adaptability to local conditions.
I suspect that grower selection may be stronger than you surmise- they can readily recognize individual females having more of the qualities they want from the general population, use that seed. As you say, open pollination tends to limit the results, but they're still real over longer time frames.
I seriously doubt that ancient wild cannabis had anywhere near the potency of landrace cultivars developed over thousands of years. The tool that farmers had to bring that out was selection.
I also suspect that cannabis & cannabis seeds have been items of trade for a very long time, leading to some hybridization among landrace cultivars. When ancient travelers & traders encountered varieties better than those from their native lands they would quite naturally take seeds home with them and native farmers would grow them along with their usual stock. The resulting diversity lends itself strongly to the process of selection.
I agree with you...mostly. I did say lightly selected. Let's put it into perspective.
Since the 1970s there has been an escalating frenzy of Cannabis breeding. The global gene pool is being stirred up at a fantastic pace. Out of all the new mixing, especially in Europe and the US, only a very few products can be called heirloom varieties, probably almost heirloom is more accurate. There are no new landraces that I know of.
For example, I am growing a few Skunk #1 from open pollinated seed I made that are pretty much the same as their Skunk #1 parents. They are growing with about the same variability as I expect from any of the other heirloom veggies I grow. So I think Skunk #1 is a good candidate for open pollinated heirloom.
The concepts of landrace and heirloom are relatively modern developments of scientific agriculture. Likewise is the concept of hybrid varieties. Before the 19th/20th century people just planted the seed they had saved. Sure, they saved seeds from their best plants when they could and sure, that caused varietal improvement but it wasn't very scientific and changes came very slowly.
That's enough for now but I would love to talk about "ancient wild Cannabis."