[newsyyswen]

I think I remember being taught in a college biology class that cannabinoids may have evolved as an anti-microbial / anti-insecticide defence. Sort of like capsaicin, or aromatics like lavender.

So this doesn't surprise me, but...it was college. My memory might be flawed.

[code_duck]

As far as the evolutionary purpose, it’s worth noting that cannabis produces many of the same terpenes and related chemicals as other common herbs or fruit, including carophyllene (black pepper, cloves), terpinolene (nutmeg, cumin), myrcene (hops, mango), limonene (citrus, rosemary, citronella, cilantro), pinene (conifers, basil) and dozens of others.

The resin glands are also quite sticky when damaged, which could play a role as a physical defense against insects.

[hypertele-Xii]

I'd think they work against large animals as well. If you were a herbivore mammal and the plant you were eating made you more hungry, thirsty, tired, and sexual, you'd probably stop eating it and go find water/shelter/mate or otherwise wander off in a haze.

And then there's humans, those weirdos, who eat anything no matter how poisonous.