Because most hermaphrodites do have to date. In other words, they cant simply fertilize themselves. When these molecular calling cards hail from different animals, the proteins come together and allow fertilization to occur.
Why would a female self fertilize?
As an evolutionary and reproductive mechanism, self-fertilization allows an isolated individual to create a local population and stabilizes desirable genetic strains, but it fails to provide a significant degree of variability within a population and thereby limits the possibilities for adaptation to environmental ...
Can female bone marrow produce sperm?
Female sperm Nayernia says that researchers have produced the same early-stage sperm cells in mice from bone marrow cells taken from female mice. “It should be perfectly possible for fully functional mature sperm cells to be made from these female-derived cells too,” he told New Scientist.