The definition of polygamy clearly states the fact that a single individual concurrently carries a relationship or mates with one or more of the opposite sex. So far, there is nothing new with this description, but it needs to be further broken down into various subheadings: polygyny, polyandry and polygynandry. Because Greek terms are not crystal clear in most cases, each category merits a more extensive characterization, even though the common denominator ‘poly’ simply means ‘more’.
The first type, polygyny, is the most common type of polygamy amongst vertebrates (including humans, to some extent), and has been studied far more extensively that the other types. ‘Gyny’ means ‘woman’ or ‘wife’ in Greek, so it is easy to see that this kind of behavior implies that an alpha male mates with many different females, thus becoming the leader of a harem-like structure. Oddly enough, the females are predominantly bound to a single male. Mice, horses, lions and hippos all exhibit polygyny and, well, Arabic harems are paradigmatic of some Eastern civilizations. It is suggested that a desire for multiple sex partners is an intrinsic trait of human biology, but many advocate that it is just a response to the lengthy sexual abstinence that follows childbirth.
The second type, polyandry, is a breeding adaptation in which a female mates with many males, being defined as the exact opposite to polygyny. As odd as it may seem, this practice poses a lot more evolutionary advantages: it encourages sperm competition between males post-copulation (literally ensuring ‘the survival of the fittest’) and multiple sperm lines may confer more variation traits to female’s offspring, thus allowing different lines to excel at different roles within the community, as is the case of the honey bee.
The final category, polygynandry, occurs when two or more males have exclusive relationships with two or more females, consequently coming to closer to Huxley’s postulate. The number of males and females doesn’t have to be equal and in the vertebrates studied so far (including Bonobo chimpanzees), the male number is usually lower.
As one of my teachers wisely put it, the biggest favour one could do Mother Nature is to board the first plane that flies halfway around the world and settle down in that area, thus making sure that the gene pool will greatly benefit from a significant variation. But are humans really meant to be monogamous and does the head of the family need to be an alpha male? Or can a woman assume just as important a role (hence the whole ‘queen bee’ subculture)? The truth is neither monogamy nor polygamy are right or wrong because eons of evolution have failed to define one thing: what the optimal relationship between a man and a woman is. As always, what we need to survive is to be happy and content with the way we live.
Image credit – farm3.static