HOW WE DO IT

Martin, the curator of biological anthropology at the Field Museum in Chicago, examines reproduction from “the basic biology of sperms and eggs up to the complexities of birth control and assisted reproduction.”

This comprehensive study covers the evolution of reproductive systems at the biological, social and sexual levels. The author begins with the emergence of single-celled organisms (with proper nuclei) more than 1 billion years ago. This was the point of origin of the chromosomes and mitochondria that govern our human genetic systems. Martin searches out correlatives to human social organization, both monogamous and polygamous, in the anatomy and behavior of primate populations. He advocates prolonged breast-feeding and also addresses the roots of monogamy and incest avoidance. He reprises the social history of our understanding of reproduction, which, he surmises, began with the domestication of animals. It was generally recognized at an early point that some form of conjugation between males and females was necessary for reproduction to occur, but the details remained obscure (as witnessed in some primitive populations). The discovery of sex cells awaited the development of microscopes before the actual mechanisms could begin to be determined. Martin examines the process of human fertilization and the several-days lag that can occur between copulation and conception. He reveals surprising studies in which the time of copulation (or insemination) was accurately determined; these studies showed that conception could occur on almost any day of the cycle (before or after ovulation). This may explain the occurrence of some miscarriages and fetal abnormalities—the assumption being that either the sperm or egg was no longer in prime condition—and also accounts for poor estimates of the true length of a pregnancy.

A fascinating treatment of a complex subject.