As we enter the twenty-first century, a number of medical, environmental, and social changes have profoundly affected human reproduction. This book discusses some of the more dramatic changes in an accessible manner, illustrating the ways in which human biology and culture can affect fertility. It provides a unique interdisciplinary perspective on the subject. Topics of discussion include medical technological advances that equip us with potential cures for many causes of infertility; diseases, such as AIDS, that have a devastating impact on the reproductive and social lives of humans; increasing industrialization and the development of fabricated materials that pollute our environment in unforeseen ways with possibly devastating effects on human health and fertility; and social revolutions that profoundly alter human relationships, such as nonmarital unions between heterosexual couples, same-sex relationships, and adoption and surrogacy.