Introduction

Machen: From a Darwinian perspective, monogamy seems a little weird. If you're a male mammal, you could theoretically impregnate a different female every single day of your life. Monogamy is putting all of your eggs in one basket and then limiting yourself to the eggs that happened to be in that basket. Machen: It evolved in our lineage to an extent. And in some of our cousins, too, in the Gibbons. The Siamang, Simflangas, Sindactalus are my favorite species of Gibbon.