ABSTRACT
Although considerable efforts have been made to understand the emergence of the first living systems, we still do not know when and how life originated. Since it is sometimes possible to correlate major evolutionary changes with environmental conditions, several attempts have been made to infer the conditions in which life arose by studying the oldest known organisms. An example of the fruitfulness of this approach may sometimes have is found in the ideas ofOparin (1938), whose suggestion that anaerobic heterotrophy was the primordial metabolism led to the hypothesis of chemical evolution and, eventually, to the development of prebiotic chemistry and other related origins-of-life research (Miller et al., 1997).
