This delightful and to-the-point book goes over the necessary material to understand the battle between monogamy and polygamy. It explains how each of the two strategies are evolutionarily advantageous, but also goes over their down-sides. Lots of examples are taken from zoology (gorillas, bonobo monkeys, prairie voles, etc.). Putting humans under the same zoological microscope, a myriad of evidence suggests that we fit the class of "mostly monogamous".
The end of the book is a little patronizing, as if trying to soften the news for those who have trouble accepting our biological reality.
All-in-all, a great little book. Well worth a read (or listen).