The Bible does not necessarily affirm all that it relates.
>There's plenty of verses telling us to obey governemnt laws if they don't
>conflict with God's law. As far as an absolute moral aspect, it seems like
>polygamy didn't work well in all examples discussed in the OT-one wife
>favored over the other, quarrels among wives or children, etc. However, in
>the case of evangelizing a polygamous culture, it seems that polygamy is
>better than divorce (particularly if wives are dependent on their husbands
>in the culture - non-favorite wives become outcasts).
> There's plenty of biological evidence favoring polygamy as a normal
>condition for hominids, including the widespread acceptance of the
>practice, strong sexual dimorphism, and females being smaller and younger
>at maturity. Also, gorillas have harems.
> Although "evolutionary predisposition" is often claimed as a
>justification for various sexual behaviors, it is usually for something
>more socially acceptable than a harem. It also relies on the assumption
>that if it can be justified evolutionarily or blamed on one's genes, it is
>OK. However, many things can be justified by these criteria yet are
>considered wrong by people who invoke these standards (e.g., rape or racial
I'm going on unreliable memory here, but I think from a secular perspective
there's lots of evidence against polygamy--for example didn't G. B. Shaw
express himself vehemently about polygamy circa Utah's statehood.
Something to the effect he cannot imagine a less civilized practice than
polygamy. Of course, the Brits enjoyed sniffing at the uncivilized
Americans for any number of reasons back in those days.