I remember years ago reading about a study done on foxes that were tamed or domesticated from wild foxes for the fur market but as generations went by in domestication their ears, coat, tail carriage, and disposition changed since the folks wanted and chose "calmer" foxes they somewhat lost the necessity for the wild attributes controlled by these adrenal gland hormones.
This is waaay too deep and really stretching my pea brain and minimal education and I'm not smart enough to be able to apply it in any reasonable amount of time for it to be of any use to me other than maybe have a tiny bit of understanding as to how it works and came about.
the foxes you are talking about changed very quickly...the researchers thought it should take many generations before these drastic changes could occur...they were wrong, as many they have been in many other cases...nothing new about that...
one theory on what caused this is when they were selectiong the foxes to breed, they were looking for the traits that were people friendly and also for not being shy towards people...when selecting for these traits there were other traits that were tied to those traits such as the tricolor and droopy ears...
I also believe as I have posted before...folks say to pick pups for intelligence...many do not or cannot explain what that means...
Just like the foxes...when we pick for winding, drifting and ranging...we are looking for those traits...but when we are looking for those traits, we must realize that those traits are tied in directly to intelligence...so selecting for those traits as natural ability we are also indirectly selecting for natural intelligence with most not knowing that this is actually happening...this is a personal theory, but I would bet money on it to be right...
