Oh my word

Someone in my class just started passing around a "petition" of a sorts in which it states that the students of my Biostatistics class are completely dissatsfied with the professor and findhim unble to teach the class adequately. I was completely stuned and appalled. I cannot believe that this is going around. I did not sign it and there are one or two others who did not sign it too. Here though, student evaluations are looked upon highly. It can make or break a promotion. My prof is a visiting professor this term, but I have heard that he is trying to become permanent faculty. So this can seriously hurt. I know that there is a problem here since a large percentage of the class is not happy with this class... but I don't know that this is the appropriate response.