This is not a new theory by any means.
I remeber biologists and scientists such as Dr. Val Geist, Charles kroll, Leonard Lee Rue, etc., explaining this numerous times since I was a boy.
basiclly, if you shoot all the big bears in an area, you end up in a generation or two with a whole mess of big eared, skinny bars!
It's quite a bit more complicated than that mind you, but that is the gist of it......
Cat