I know many species are able to store metabolic byproducts, poisons from food, etc in glands and secrete them at will. Could a human possibly evolve to store and secrete acetone from cellular processes in a similar manner? Particularly glands in the palms and soles? If so, how exactly could this work? How long would it take for such an ability to evolve? By the way, this is just another weird question for my weird book, any help appreciated.

We do a bit, so not entirely impossible.

 

As for how long it would take to evolve, I would say it depends on the why it was needed in the first place.

Actually the liver metabolises and secretes ketoacids, acetoacetate and beta hydroxybuturate. They convert to acetone in the body, which is why in Diabetic keto acidosis patients develop acetone breath.

 

I'm not sure if an organ can store acetone to great concentrations - the metabolic process to synthesise acetone produces organic acids, and at higher concentrations it may lead to acidotic poisoning.

The big problem with "storing" acetone is that it's a small, fairly polar, molecule and will diffuse rapidly through cells.

It would be difficult to stop the stuff leaving the "gland" and being dissipated in the bloodstream.

The big problem with "storing" acetone is that it's a small, fairly polar, molecule and will diffuse rapidly through cells.

It would be difficult to stop the stuff leaving the "gland" and being dissipated in the bloodstream.

 

Well if storing the acetone would be dangerous and difficult, perhaps only pulling it from the bloodstream to the palms when needed would be possible? I'm not really sure if/how that would work, how fast the skin can secrete things, or how much acetone the body even produces....It's for a pyrokinetic hominid species in my story, so I'm trying to keep their abilities as "realistic" as I can. Any other ideas are welcome too.