First example: anecdote. The example suggests a narration, particularly through the words "outcome; left alone; etc". The situation also shows that either what preceeds or follows is a experience, that is an action.
Second opinion: expert opinion. This kind of supporting evidence is usually given by professionals, in this case a doctor. The word 'helpful' suggests it is an opinion rather than a fact.
Third example: fact. The use of the present simple tense and the fact that the information is specific shows that it is a fact.
Fourth example: emotional appeal. This kind of supporting evidence uses a variety of words full of emotion. In this example, emotional words include "pledge; striving; and vulnerable". The example appeals to emotions, which is the purpose of this type of evidence.
The domestication of horses behavior changed quite a lot because before they were domesticated they were WILD horses. So they probably were aggressive animals. Considering how big horses are they definitely would have kicked you if you approached them. Since horses have been domesticated they act less hostile. They have also became smarter, they have a really strong fight or flight system.
(I don't know if this helped, but it took me awhile to find this information)
