Marriage is what distinguishes us from chimps (at least some of us). See this excellent article:
http://spectator.org/archives/2012/08/3 ... t-to-be-me
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Let's start with a simple observation. Biologists have recently determined that when it comes to genetic structure, we differ from our chimpanzee cousins by only 3 percent of our genes. That means, if you believe in evolution, that there is very little distance between ourselves and the chimps. In the 5 million years or so since we branched off, only a few minor changes have occurred to separate the two species.
Now here's the interesting part. Of that 3 percent of changes, 95 percent have taken place on the Y chromosome. That's the chromosome carried only by men -- the only thing in fact that differentiates men and women. In other words, pretty much all the things that have happened to separate us from our chimpanzee ancestors have been things that happened to men. Does that make the term ""mankind" sound a little more appropriate?
Actually, to anthropologists, this isn't anything new. For decades, they have noted that, in terms of reproductive behavior, female chimpanzee and human females are not very different. Both become pregnant, nurture the fertilized egg in the womb, give birth, nurse their offspring, and then carry them around and protect them for about five years until the young are ready to venture out on their own. In behavioral terms, there's not much any difference.
What is different about human beings is the behavior of men. Male chimps band together in "brotherhoods" that are often compared to tight-knit fraternal clans or street gangs. They mark out territory and defend it against other males. This creates a safety zone in which their females can raise their young without worrying about unprovoked attacks from unrelated males. (This is critical because if other males take over the troop they will immediately kill all the young in order to put the females to work raising their own offspring.)
What male chimps do not do is: a) pair off with individual females, or b) play any role in child-rearing. In fact, it is against the code of chimpanzee society for any male and female to take too much interest in each other or pair off. Instead, the strict rule is that every male gets to mate with every female. This maintains the brotherhood and allows male chimps to cooperate among themselves without being torn apart by sexual competition. The females enforce this code as well, making sure to mate with every male, no matter how low his status. This is called "confusing paternity." The purpose is to make every adult male believe he might be the father. That prevents any of them from harming the offspring.
Now, somewhere in the mists of time, on the Savannas of East Africa, our ancestors abandoned this sexual communalism and adopted instead a system where couples paired off to form monogamous "pair bonds." This is rare among mammals, although not entirely unknown. About 5 percent of mammals practice monogamy. Among them are our distant cousins, the gibbons of Southeast Asia. Gibbon couples pair off in the jungle and live in solitude, singing weird, haunting tenor-and-soprano duets to warn other males and females out of their territory. They reproduce successfully but do not engage in co-operative effort with any other gibbons.
What was completely unique about the proto-human society of our forebears is that they learned to practice monogamy within the larger group. This occurs among gregarious flocks of birds that spend weeks or months nurturing their young but is unknown among other mammalian species. What it accomplished was to maintain the male solidarity of the chimpanzee troop under much more trying circumstances, while still providing each individual with a reasonable chance to mate. The outcome paved the way for human evolution.
Our earliest ancestors were hardly formidable creatures. They stood three feet tall, had no sharp claws or ferocious teeth, could not outrun predators and had no trees in which to escape. Yet somehow they managed to hold their own in a sea of larger, swifter predators. By sticking together in troops of about 20-25, they were able to protect themselves while scavenging the prey of other animals and eventually becoming hunters themselves. Male chimps hunt for about 5 percent of their diet and do not share with females or offspring. Hunter-gatherer males provide about 35 percent of the diet and share their kill with both mates and children. That is the difference between us and the chimpanzees. It is a legacy of which any male can be proud.
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