All valid Points.
But also, humans: i will care for this plant and create huge fields where you can live prosper and in peace. We kill everything who comes near you and try to harm you. And we will ensure you will live forever.
You dont need birds who shit your seeds out.
TBF, life's objective is to reproduce and keep its genetic materials continuing on. Even if humans propagate and consume said plant because they find it desirable, that is still a success for the plant. So even if it has toxic caffeine or fiery capsaicin to deter some pests and humans find it enjoyable, the plant wins.
Would aliens actually be weirded out by this quality of humans?
I feel like any sufficiently intelligent species living on a planet will have some degree of biodiversity on said planet. And the chances of something being made to be a poison/deterrent for creatures other than the intelligent species is probably a large one, because it's pretty hard for plants and animals to make a poison/deterrent that kills everything without also killing itself. So if there is a gap for itself, there is a gap for other life to coexist with the toxin. And that's before accounting for the fact that something can be safe at low levels, provide benefits/stimulation/good feels at low levels, and toxic at high levels.
So I'd think it would be pretty natural for intelligent life to consume things that are harmful to huge swaths of other creatures.
It is kinda weird that humans are so resilient to so many things though. It's part of being scavenging omnivores, but alients with a more specialized diet might be weirded out.
I know it's just a typo, but the image "alients" conjured in my head is pretty funny. I have less than zero artistic talent or I'd share it with you all. Hopefully the mental image is enough.
Based on this list, something on the order of like 99.5% of plants are either not safe, or not useful/beneficial. If other species on our planet share a similar rate without complete overlap, then it's practically a guarantee that there will be thousands of plants that are safe and useful for us but not for other species. That doesn't feel particularly strange or unlikely. So even with a specialized diet, I don't think the numbers would be much different.
It also could be the case that being scavenging omnivores is a strong precursor to becoming intelligent. If your species is on the rise in terms of intelligence, you're probably using that to expand your food sources wide and far.
For mammals we are, sure, but there's loads of things that'd kill humans that other animals chow down on perfectly happily, especially when it comes to microorganisms, mushrooms and the rotting things they're often found in/around
I don't think scavenging is right also given that humans used to mainly pick fresh fruits and persistence hunt, both of which are very fresh food which is not overlooked or left by others... Given the fact we picked fresh fruits and hunted for fresh meat, being resistant to berry and fruit based poisons was more important than microorganism based ones, so it makes a lot of sense that so many of the non-intoxicating poisons we like are from fruits and berries
If we were the aliens and came across two worlds inhabited by intelligent life I would probably be more weirded out by the one where nobody uses any mind altering substance like caffeine that are poisonous to other animals.
I think the book Sapiens makes the point that wheat has trained us into cultivating it for selfish needs.
(Except that it's wheat, and that we annihilated 99% of its brethren to pick out the one that we liked so we could effectively clone it. But yes, we are the slaves...)
Sometimes, when a fruit or seed isn't toxic enough for our taste, we make it liquid then make it ferment or age until some of its sugar turns into the deliciously neurotoxic ethanol.
Tbf, this has proven to be extremely effective: Just think of how many tobacco or chili plants are grown today!
Domestication really is a two-way-street
95% Alcohol(any kind, ethanol, isopropyl, methanol) is a cheap, highly effective, contact killer. Spray any bug with it and it will die. Either the alcohol kills it from the toxicity or from dehydration because the alcohol cleaned off its protective wax surface.
Caffeine is poisonous to us too, so I think it's more accurate to say that humans enjoy the side effects of that particular neurotoxin. It's generally not possible for someone healthy to drink enough coffee to die, but they sell pure caffeine (for research) and even seemingly small amounts of that will kill a person.
You can buy 200mg pure anhydrous caffeine pills at Walmart for like $5. It's abundant and as safe as coffee if you don't go nuts. The max daily recommended dose is 400mg, anything past that could cause harm
What I had in mind is more like this 25kg bucket. That's enough to kill about 2,000 people, which is actually a lot fewer people than I would have guessed before I looked up the LD50.
I've never actually seen caffeine in a bucket myself, but I worked in a lab once that had a big plastic jar of it.