In other words, it's been changed as it's been passed down but it still goes back to some ancestral DNA, like how Roman-era fermented anchovy sauces eventually mutated into modern Worcestershire Sauce. We certainly have a lot more in common with the Romans than we do with the marriage customs of one isolated community which I can't for the life of me remember the name of right now, where the woman picks the man and keeps the children in her house while the man lives with his own family and helps raise his sister's children.
All I was doing was using a specific case to make a general argument, which was that the concept of marriage cannot be co-opted by the religious as a religious invention, theirs to define. Some aspects of modern marriage derive from pre-Christian traditions. Some from post-Christian traditions. Others are common throughout the world, whether Christianity has influence there or not. That's all. Because this is a country dominated by Christians they seem to want to think they get to make the rules and define the world "traditional", as if all of our customs were invented by Sam Adams and George Washington in a Boston tavern in 1780.