“…Such a model has received some attention in the literature; see, for example, Rösler (1996, 2002), Bagley (1986), Bruss (1984), Daley et al (1986), González and Molina (1996, 1997), or Hull (1982. More recently, with the objective to model the probabilistic evolution of more complex two-sex populations, various classes of bisexual branching processes have been introduced and some theory about them developed; see, for instance, González et al (2000González et al ( , 2001, Molina et al (2002Molina et al ( , 2003Molina et al ( , 2004aMolina et al ( , 2004b or Xing and Wang (2005). We refer the reader to Hull (2003) for a survey about the literature associated with the bisexual branching processes.…”