Does my son's father have parental rights if he has never been involved in my son's life?

The father will not lose his prental rights unless there is a court order that indicates that he does not have the right to make any decisions.  Since the father has not been around at all then there is no real concern that he wil meddle with your child's right.  if there are certian decisions that need to be made regarding your daughter, then you are going to make them as he is not in her life.  If you want to terminate his parental rights, then you may need to make a motion in court and provide him with notice that his rights are at risk of being taken away.  I suggest that you avoid taking his righs away as you never know what will happen in life.  maybe the father will turn his life around and want to be a part of his daughter's life.  while it may be a little too later, the question is what is in the best interest of your daughter.  if you believe that the father is nothng but trouble, then take legal action and hire a lawyer.