 For instance, Tim Bayne (2003) argues that both Benatar and Nelson are committed to including biological grandparents and great grandparents etc. amongst those who acquire parental responsibilities for donor-conceived children. Bayne thinks Benatar is committed to this conclusion because subsequent generations are the result of an individuals’ exercise of reproductive autonomy. He thinks that Nelson is committed to this conclusion because biological grandparents and great grandparents are necessary causes of their donor-conceived children, and so satisfy Nelson’s criteria for parenthood.