Well played, Learner.
But I don't think test tube is the best option to have used, simply because, they test on living things to show effects on living things. testing in tubes wont show the same responses.
I do agree with you though, animals should never be involved unless it is a medicine FOR animals.
Humans should realize if they want the best test results, they need to test on people.
Based on your update, and other answers this looks like a callout against animal testing (I have no idea how one would derive that from your question alone).
Why does it exist? Because scientists don't want to test on humans, or stem cells?
Do I like it, no.
I'm not sure what the question is.
What part of vegan and vegetarian cooking does this question have to do with???
Can't tell the difference between a test tube and an ape?
