The Silliman Lectures at Yale University have been responsible for many books which have greatly influenced the progress of scientific work in the twentieth century. One of the foremost scientists of our time, Theodosius Dobzhansky, recipient of the Elliot and Kimbler prizes, and Da Costa Professor of Zoology at Columbia University, delivered the Silliman Lectures given in honor of the Centennial of Charles Darwin's On the Origin of Species. Based upon these lectures, Mr. Dobzhansky's latest book, Mankind Evolving, now takes its place beside his other great works.

With a...