Are not all chickens hybrid? After all, pretty much any pure breed we mention now was a cross of 2 different types of chicken breeds a hundred or so years ago. So what makes them pure breed now, and if we have a cross these days between 2 different types of chicken, it becomes a hybrid? I just don't get it. Do I need to understand genetics in detail to properly understand the difference between hybrid and pure breed? Sorry if it's been asked before, I could not find thread.