Evolutionary biology is a subfield of biology that focuses on the natural biological evolution of organisms.
Casually Explained is a great video series, here is Casually Explained explaining evolution. I suggest checking out the overarching YouTube Channel.
Charles Darwin came up with the idea of natural selection, but he didn’t coin the phrase “survival of the fittest”, that was Herbert Spencer in 1864’s Principles of Sociology.
In pop-science, in reference to the brain, you’ll hear the terms “hardwired” and “softwired”, hardwired means genetically programed and softwired means learned.