Some primitive tribes believe that a baby inherits the most desirable characteristics of each man with whom its mother copulates during pregnancy. This belief creates a tribal society in the form of an intimate network; making it robust, egalitarian and inhibitive to hierarchies.
In some older societies men had several wives. In others women had several husbands. In some aboriginal, ancient Celtic and Anglo-Saxon societies both men and women could have several spouses. The Inuit people even have inter-tribal intimacy in which a man refers to his wife's other "husbands" as "other me", a concept that effectively avoids inter-tribal conflict and creates an inclusive society.
Societies frequently perpetuate erroneous beliefs. For millennia the vast majority of mankind is thought to have believed that the Earth were flat and that it would be possible to sail off the edge into an infinite abyss. Formal scientific investigation ultimately proved this belief to be wrong. For millennia, the Earth was thought to be the centre of the universe. Equally, this belief too has been proven false. Even today, the vast majority of people are under the illusion that competition leads to the best products dominating the market. This too, is easily demonstrated to be false.
To be fair, the evidence to prove or disprove the above beliefs is not readily available to common man. It isn't staring him in the face. It does not impinge upon his day-to-day existence. His field of vision does not normally encompass enough space to readily see the curvature of the planet. When looking up into the night sky he can only see the universe from an Earth-centred point of view. And all he sees of the free market is the relatively narrow range of fashion-standardized products that it pesters him to buy.
There are tribes in South America, New Guinea, Polynesia and India that hold to a belief that is as ancient as any. It is the belief in partible paternity. This belief leads them to act as follows.
A woman becomes pregnant by her husband. On discovering this, she seeks out and selects up to 12 other men and engages in sexual relations with all of them for as long as is practicable during her pregnancy. She selects men who each have a characteristic she desires for her child. One man may have eyes that she likes. Another may have nice hands. And so on.
She believes that each man's sperm contributes his desirable characteristic to her developing baby. Her baby should then be born with the best characteristics of each man.
Evidence to prove or disprove partible-paternity should be directly observable by those intimately involved. For it to be true, at least some children of a partible-paternity tribe should be seen to resemble one or more of their secondary fathers in some identifiable way. I can see no reason why such a belief should prevail for so many millennia, in such diverse parts of the world if no evidence of its truth were ever observed by those in front of whose very eyes the phenomenon were taking place. Of course there are pitfalls. A child often resembles an uncle or cousin, with whom its mother had no sexual relations during her pregnancy.
Are children of partible-paternity tribes observed to inherit characteristics from their secondary fathers or not? This is a phenomenon that, if it exists, must be directly observable. It could therefore be methodically investigated by controlled experiment and the results documented. The results could at least place a Boolean probability upon its being true or not. Perhaps some anthropologists are conducting such formal research. If so, the outcome would be indeed interesting.
One mother and one father are necessary and sufficient to procreate a child. This stands proven both biologically and by common experience. Nonetheless, it does not systemically rule out the possibility that genetic information from secondary fathers could find its way into the embryonic system and could thereby influence foetal development.
As best as I can understand the process, each individual spermatozoon within a single load from a potential father has one of at least two possible functions. It can be either a messenger or a soldier. As a messenger, it carries the potential father's genetic code, which it attempts to deliver to the mother's egg. As a soldier, its job is to prevent alien messengers from a load delivered by a subsequent potential father from reaching the egg.
This implies that nature fully expects spermatozoa from one man to engage in battle with the spermatozoa from another man within the body of a woman. It is as if nature has prepared itself for this situation and fully expects a woman to engage in sexual intercourse with multiple men. But is there really a state of war between the different loads of spermatozoa?
How humans (including scientists) perceive what they observe in a natural process is influenced by human culture. War is a concept derived from human culture. It is simply an artificial framework within which humans interpret what they see happening. However, there are alternative ways of perceiving what is taking place here.
Why has nature bothered to produce soldier sperm? If humans are natural monogamists, there is no need for them. If humans are natural polygamists, why not just let the spermatozoa compete in a race to the egg and let the fittest win? Soldier sperm would still be unnecessary. Entering into battle could result in the destruction of the fittest messengers, since they will be the first to meet alien soldiers in their race to the egg.
Perhaps war is not what is taking place. Perhaps the so-called soldier sperm are not warriors at all but something else.
To my knowledge, there is no way to identify individual spermatozoa as having come from one man or another from a mixture inside a woman. Consequently, what each is doing and why is not really known. Perhaps the so-called soldiers have more the role of dustmen (trash collectors) or quality control inspectors. This would give them a collective role as that of a quality filter. They make sure that only properly functioning messengers get access to the egg.
From what I understand, the DNA molecule, which each spermatozoon carries, functions as a vast array of switches. How these switches are set determines, in part, the features and characteristics of the prospective baby. I think that the amount of information contained in the human genome is vastly insufficient for the complete specification of a human being. Consequently, I think that DNA has more the role of a job-control script than a complete construction and operating program.
This bank of switches is set within each spermatozoon, before its journey begins, to determine the precise characteristics of the prospective child. Notwithstanding, this does not systemically rule out the possibility that some of these switches could be flipped by external influence during its journey to the egg. Perhaps, where a spermatozoon from a secondary father contains switch settings for a better version of a certain characteristic, it could inductively flip the corresponding switches in the spermatozoa of the primary father by some means. Or perhaps secondary spermatozoa could inductively influence the egg itself through much smaller chemical messengers that act as switch triggers.
In this sense, perhaps as well as competing, spermatozoa from different sources could also cooperate, as is the case with people in society. Consequently, one cannot be so cock-sure (pardon the pun) that, at a deep molecular level, the genetic information-content of alien spermatozoa does not modify, or at least influence, the one that finally reaches the egg. So partible paternity remains an open question.
For tribes that believe in partible paternity, its biological truth is not significant. What is significant is the way this belief leads them to relate. It leads each to build strong intimate ties with many members of the opposite sex, thus creating a society in the form of a network rather than a hierarchy. The adjacent illustration shows a simplified view of this structure for a society in which each woman (pink sphere) has intimate links with 3 men (blue spheres) and vice versa.
The very strong and deep nature of the male-female link, plus its network geometry, make this form of social structure extremely robust. Its very structure inhibits the formation of hierarchies. It makes such a society almost impossible to subvert or subjugate. The only way the European colonisers were able to subjugate such societies was by technologically superior sheer brute force. And still to this day, many of these tribes survive unconverted to the social norms of those who invaded their ancestral territories for economic exploitation.
Apart from the isolated parts of the world where this kind of social structure survives, it appears that it existed anciently in areas now dominated by hierarchical societies. Julius Caesar witnessed it among the Celts of South-east England.
"Ten and even twelve have wives common to them, and particularly brothers among brothers, and parents among their children; but if there be any issue by these wives, they are reputed to be the children of those by whom respectively each was first espoused when a virgin."
It would seem, therefore, that this networked form of tribal community was the more ancient form of society and that hierarchical structures came along later. Ancient nations were most likely made up of loosely interlinked anthropological communities, each comprising from 50 to 150 members. Within such, people relate with each other freely, irrespective of birth or gender. Wealth, apart from the most personal effects, is common. It cannot therefore become an agent of division.
A nation of linked or overlapping network-structured communities of this kind, with the free and unencumbered use of terrestrial resources, is impossible for an elite minority to exploit. The individuals within it are too intimately connected. Therefore, before such a society can be ruled, it must first be divided. How was this achieved?
Multiple Fathers Prevalent in Amazonian Cultures
Ancient Amazonian Cultures Reportedly Witnessed Multiple Paternity
Shared Paternity in South American Tribes Confounds Biologists and Anthropologists
Evolutionary history of partible paternity in lowland South America
In the ancient Amazon, children had many fathers – and women many lovers
Culturally transmitted paternity beliefs and the evolution of human mating behaviour
Amazonian Cultures Found Social Benefits in Multiple Fathers
The Concept of Partible Paternity among Native South Americans
Sex at Dawn: The Prehistoric Origins of Modern Sexuality
The Virtues of Promiscuity, The Virtues of Promiscuity
Who says only one sperm gets the prize?