Darwin Under The Microscope

in the book which was just released, In the Light of Evolution: Essays from the Laboratory and Field, is available online as a pdf. Carl Zimmer’s chapter

The chapter explains how the study of evolution in the present day is far better understood than in Darwin’s time, due to our knowledge about genetics and the experiments have been done that allow us to witness and study evolution in the laboratory.

This is courtesy of the NCSE which also has a number of complete books made available on their web site.