Echoes of Life: What Fossil Molecules Reveal about Earth History

In 1936 a German chemist identified certain organic molecules that he had extracted from ancient rocks and oils as the fossil remains of chlorophyll--presumably from plants that had lived and died millions of years in the past. It was another twenty-five years before this insight was developed and the term "biomarker" coined to describe fossil molecules whose molecular structures could reveal the presence of otherwise elusive organisms and processes. Echoes of Life is the story of these mol...