Hot Peppers

[Laserbeak]

Originally Posted by desertanimal

Carnivores don't have receptors for sweet, if I recall.

I believe only the cats have lost the taste buds for sweetness, so they are the most carnivorous of the mammals (except for the whales/dolphins I guess). Dogs certainly still have them and wolves actually can survive on a vegetarian diet for a while if no prey is available. Cats would die. Although many cats do eat grasses and some leaves for fiber to make them "regular" and settle their stomachs, they get a negligible amount of nutrition from plants.

[katrina]

Originally Posted by Laserbeak

I thought fruits were supposed to get animals to eat them so their seeds, which pass through the gut intact, get spread far and wide along with a side of fertilizer too!

Right there is the rub...if humans (or most any mammal) eats the pepper the seeds it will likely get destroyed by the chewing. Therefore, the plant evolved a mechanism (capsaicin) to cause the mammals to avoid them.

As already pointed out...birds are the best at dispersing seed. 2 reasons...they don't chew and they fly.

[desertanimal]

Originally Posted by Laserbeak

I believe only the cats have lost the taste buds for sweetness, so they are the most carnivorous of the mammals (except for the whales/dolphins I guess). Dogs certainly still have them and wolves actually can survive on a vegetarian diet for a while if no prey is available. Cats would die. Although many cats do eat grasses and some leaves for fiber to make them "regular" and settle their stomachs, they get a negligible amount of nutrition from plants.

Good catch. I overstated. Many carnivores have lost receptors for sweet. Not all have yet been checked, but sea lions, fur seals, Pacific harbor seals, Asian small-clawed otter, spotted hyena, fossa (woot! My fave!), banded linsang, and all known cats have a non-functional Tas1r2 allele via some mutation or other, which is the one that codes for sweet receptors. But plenty of carnivores have an apparently functional Tas1r2 allele--yellow mongoose, aardwolf, domestic dog, red wolf, spectacled bear, giant panda, red panda, racoon, domestic ferret, and Canadian otter. Many of these species have also been tested for and exhibit behavioral preference for sweet. As for non-Carnivora, chickens, tongueless Western clawed frogs, vampire bats, and dolphins also have non-functional Tas1r2 alleles. Some of these species also lack functional umami taste receptor alleles, and the giant panda lacks a functional umami receptor allele while retaining a functional sweet receptor allele. This is all from Jiang et al. 2012. Major taste loss in carnivorous mammals. PNAS 109: 4956-4961 Fun stuff!

[Laserbeak]

Originally Posted by desertanimal

Fun stuff!

Yes, it's all quite interesting. I did read just recently read that the only thing the Cetaceans can taste is salt. Which sounds a bit bizarre since you'd think that's the one thing they wouldn't want to taste since they are always in saltwater! Perhaps they taste it to tell how salty the water is to adjust their systems, some dolphins do live in freshwater rivers.