Paternity and Child Support

[grandma1]

A friend of the family is getting himself into a lifetime of trouble, and I have a question.
If a young couple (19 years old) gets pregnant, but break up before the baby is born, and the father signs the birth cert assuming and claiming the child to be his, does the mother still have to get a dna paternity test before she can claim for child support? I thought I read that somewhere, that the mother has to have a positive paternity test if the couple is not living together as a family.
I'm asking this because this young man won't ask for the test, but everyone knows that the baby isn't his. He questions, but won't voice it, hoping that she will consent to take him back into a relationship.
Another question, can the paternal grandmother ask for the test, considering he is still living with her, and she will have to support him as he supports this child?
Thanks for considering my question.
Grandma1

[Attorney Howard Iken]

Before a hospital will allow an unwed father to put his name on the birth certificate, they normally have him sign an Affidavit of Paternity. Under Florida law, if the affidavit is not challenged for 60 days, the establishment of paternity is permanent.

Yes, he is about to commit to a lifetime responsibility.