Chapter 2 Summary and Analysis

Chapter 2 begins with a fictional account of a Martian visitor who has been studying humans for several years but has not returned to give his report to his superiors on Mars. After hearing his report on how humans reproduce, the Martian's superior asks him why humans have sex. The Martian scientist responds that no one on earth has any idea why they have sex and not some other form of reproduction. The question of "why sex" and not some other form of reproduction is important for human scientists as well as Martian ones. There are many ways for an organism to reproduce. Many organisms reproduce asexually or in some other way. Why has sexual reproduction based on two and exactly two parents of different sexes become the norm for humans and many other species though?

The question may seem silly, but...