Given the importance of children as a genetic vehicle, it is natural that natural selection facilitated the development of powerful mechanisms to ensure survival of species. It is thus strange that many animal species do not bother to bring up their young ones. In some species both parents are involved in bringing them up, in others the mother is more committed than the father and in still others vice versa. In the first case parents have so many offspring that they don’t worry about looking after them as whatever happens, a few will probably survive. This is common in fish. In the second case if fertilization occurs inside the female’s body, not only is she blocked for the entire pregnancy, but then, given how much she has already invested, it is unlikely that she will abandon them. In this case the father is less involved as he has the assurance that the offspring are being looked after (and also is not absolutely certain that he is the father). Consequently, he invests less than the mother in upbringing and uses his relatively intact energies to go around fertilizing other females where once again he is less committed than the mother. If fertilization occurs outside the mother’s body, with the female simply laying the eggs, as in a number of aquatic animals, one would expect both parents to be equally involved in bringing up offspring. Researchers are puzzled to discover that in 46 examined species, in 80% of cases it was fathers who looked after the offspring