3 minute fascinating podcast. 

From an evolutionary perspective, a central nervous system has two main functional aims:

1) avoiding damage (where the sensation of pain and learning from those negative experiences is central) 

2) seeking pleasure (shelter, food, sex etc.). 

So I really don’t undestand why some scientists still question whether or not some animals feel pain. It’s ridiculous. How did they become scientists to begin with if they are missing this fundamental understanding?