Recent Excitement about the Archaea

Abstract

this planet for approximately 3.7 billion years--3 billion years longer than plants and animals. The development of higher life forms on Earth was dependent on microorganisms, and the continued existence of plant and animal life absolutely requires the continued activity of microbial life. Higher organisms are even known to harbor microbial derivatives in the form of mitochondria and chloroplasts. From the initial production of free 02 by cyanobacteria in the early evolution of the earth to the continuing role that microorganisms play in geochemical cycles, the entire biosphere is dependent on the activities of microorganisms. Certainly, as Carl Woese has said, "to study microorganisms is to study the biosphere" (Woese 1998).