The last link was actually some official Pit Bull site and if you go to the "responsible Pit Bull Owner" page it has five criteria. Guess what number one is? Not to breed these dogs. There is an explosion of them, they say. Why? Because a higher percentage of irresponsible people (uncontrolled litters, fighting, neglect, whatever the reason) have an affinity for these dogs and are allowing them to procreate in an uncontrolled fashion. If you know anything about genetics and assume (incorrectly) that they are all starting the same, this factor alone would naturally select for the most aggressive animals to survive. I am not convinced that there are many pro-Pit people in this debate who really have an understanding of genetics and natural selection. I am guessing Oren does and I cannot explain his position. I would really like to know who has taken genetics and who has not, just for my own understanding. If you have had genetics or have a degree in Biology, I am all ears. Not that your opinion does not matter if you have a Hospitality degree or did not go to college, but there is a point where if you say "natural selection" and someone tells you about their dog Brutus...well..we are going in circles here. It is a multifactorial result, no doubt, but you can argue all day about training and it cannot negate the genetic variable.