'A man who may be the father of a child, but whose biological paternity has not been established, or, in the alternative, has not achieved presumed father status, is an 'alleged' father.' (In re Zacharia D. (1993) 6 Cal.4th 435, 449, fn. 15 [24 Cal.Rptr.2d 751, 862 P.2d 751] )