Chapter 1 Opener: Charles Darwin’s study

1.1 The monogamous prairie vole

1.2 The brain of the prairie vole is a complex, highly organized machine

1.3 A gene that affects male pairing behavior in the prairie vole

Box 1.1 How are phylogenetic trees constructed and what do they mean?

1.4 The evolutionary relationships of the prairie vole and six of its relatives

1.5 The possible history behind monogamy in the prairie vole

1.6 The connection between evolutionary history and the mechanisms of behavior

1.7 Testing the hypothesis that monogamy in prairie voles is linked to a specific gene

1.8 Charles Darwin, shortly after returning from his around-the-world voyage on the Beagle

1.9 A variable species

1.10 Natural selection

1.11 A band of Hanuman langur females and their offspring

1.12 Male langurs commit infanticide

1.13 Variation in suicidal tendencies in a make-believe lemming-like species

1.14 Infanticide by a male lion

1.15 An evolved response to the risk of infanticide