I already commented on this in this thread, but describing the concept of something and the something existing are two different things.
The concept of empathy was first introduced by aestheticians in the mid-19th century. They used the German word “Einfühlung” to describe the emotional “knowing” of a work of art from within, by feeling an emotional resonance with the work of art.
Sliced bread also wasn’t sold in stores until the 20th century, but people were slicing bread long long before that. People have been experiencing empathy since before we were homo sapians.
Prosocial behaviors have many origins and its multi factorial, the interplay between them are complicated. But it’s not like the feeling of empathy isn’t part of our genetic make up.