More Mothers than Fathers

On this Mother's Day, it's appropriate to acknowledge that, in nature, there are more mothers than fathers.  Among the many invertebrates, fish and amphibians that utilize external fertilization, the designation of genetic parenthood is not always possible, as clouds of eggs and sperm mix in the sea or in a pond.

Among most other animals, monogamy is uncommon though couplings may occur for a given breeding season, thereby defining genetic fathers and mothers.  However, in some species, especially in large herbivores, males spar for mating rights; the victors are then free to assemble their harems and impregnate the females.  Examples include wild horses, elk, musk ox and bighorn sheep, among many others; similar relationships occur among some carnivores and primates, where the alpha male does the breeding.  Even humans participate in this imbalance, as young men irresponsibly impregnate a number of women or, as more responsible citizens, donate to their community sperm bank; then, of course, there are men that father children with a string of wives (a practice far more common than the reverse).

It thus follows that there are more mothers than fathers on Planet Earth.  On Mother's Day, we stop to honor that responsible majority.