The origins of amino acids in ancient terrestrial and extraterrestrial materials

摘要

The earliest evidence for amino acids on Earth is in Precambrian sedimentary rocks with varied metamorphic histories. Igneous rocks rarely contain such compounds, exceptions being those introduced via the migration of fluids into fractures subsequent to crystallization. Martian meteorites are excellent examples of ancient igneous rocks that apparently contain amino acids associated with minerals precipitated in rock fractures. The challenge has been to determine whether the organic compounds present in ancient terrestrial and extraterrestrial materials are indigenous and, if so, are representative of past life or pre-biotic synthesis. A summary of what is known to date about amino acids in ancient terrestrial and extraterrestrial materials is presented. Alternative approaches for distinguishing their origin(s) are discussed.