“Scientists have proposed that humans have a history of polygyny before (our sperm, for example, looks like the sperm of polygynous apes and monkeys, for example). But with these new DNA results, the Arizona researchers have made a powerful case that polygyny has been common for tens of thousands of years across the Old World. It’s possible that polygyny was an open institution for much of that time, or that secret trysts made it a reality that few would acknowledge. What’s much less possible is that monogamy has been the status quo for 50,000 years.
People are perfectly entitled to disagree over what sort of marriage is best for children or society. But if you want to bring nature or tradition into the argument, you’d better be sure you know what nature and tradition have to say on the subject.”
This is from Carl Zimmer’s blog here.