In a recent thread on How do we feel heat?, engineer_comp_geek said :
The way I understood this situation was that pepper plants evolved to have capsaicin in the fruits - so that animals that help propagating its seeds did not feel the heat and other animals felt the heat.
Did I get this correct or did peppers always had capsaicin in them and it was actually the animals who evolved to *not feel the heat *?
You have it correct. It’s basically mammals who are sensitive to it and birds who are not. I expect most other animals aren’t sensitive either, but most fructivores are birds and mammals. While there might be some evolutionary pressure on an animal to become desensitized, as long as there are plenty of other non-spicy food sources the pressure isn’t going to be too strong.
Thanks. I had a pet parrot that used to love to eat hot peppers.
Its incredible how the plant figured out and evolved to make themselves attractive to birds but unattractive to animals.
I bought some "squirrel-free’ birdseed that was based on this idea - it was supposed to be too hot for those pesky beasts to eat, but birds would like it just fine.
All I can say is that I evidently have the world’s only “Tex-Mex appreciating” squirrels living in my backyard - they snarfed that shit down like it was going out of style, and asked for seconds.
So far, the squirrels have outsmarted all of my attempts to feed birds and not them.
Their even bigger trick is finding the one stupid mammal species that can detect capsaicin but for some reason doesn’t avoid it, and enslaving that species to not only spread their seeds, but to plant, fertilize, and irrigate them as well. Diabolical.
Indeed.
OTOH, it’s easy to understand why a mutation that caused a plant to produce a chemical like capsaicin would confer an evolutionary advantage, thus causing such a plant’s DNA to be disproportionately represented in succeeding generations.
That’s not the only way. Blackberries and their relatives pull off the same effect using thorns. Perch on top with scrawny little legs and poke a small beak at the berries, and you’ll probably get out without a scratch. Try to poke in a whole huge big muzzle attached to an even bigger body standing on the ground, and you won’t be so lucky.
shrug You say tomato, I say solanum lycopersicum.
You know, I actually heard it was the other way around. Birds have very few taste buds, and everything is bland to them. But they like eating chillies because its something they actually
CAN taste.
So, that’s wrong then? Or maybe true of some birds?
What I don’t understand is how a lot of capsaicin can cause physical harm if all it does is immitate the sense of ‘heat’. Eat one of those bhut juloka peppers (or whatever they’re called) and you can get all sorts of physical problems aside from a red face.
A physical problem for the animal. But from the plant’s point of view, its seeds have been distributed and fertilized.
Yea i get that. I’m wondering why the fake sensation of heat in the animal (as opposed to an actual fire) causes physical problems. And I don’t just mean choking. You can get actual chemical burns from pure capsaicin can’t you? Just rubbing it on your skin. And indigestion, hearthburn, etc. All from the fake sensation of heat.
The sensation of heat might be fake, but the stuff is genuinely chemically interacting with your taste buds and mucus membranes. The heat is fake, the irritation is real.
it’s interacting like any other chemical that touches my tongue/taste buds. The flavors of a banana are chemicals causing a chemical reaction. That alone doesn’t explain it.
Salt can damage tissue as well in high enough concentrations, even though we need a little bit of it to survive. Some chemicals are more irritating than others, and capsaicin is one of those that in high amounts is damaging.