初期地球における局所還元環境とアミノ酸生成の可能性

抄録

Sources of prebiotic amino acids on the early Earth can be classified into those having extraterrestrial origin and those that have formed on Earth. The extraterrestrial origin via carbonaceous chondrites is widely accepted as a major source of prebiotic amino acids, because many of these carbonaceous chondrites actually contain amino acids. Besides this, formation of prebiotic amino acids on the early Earth can also be another possible source. Although the atmosphere of the early Earth was thought to be only slightly oxidative, wherein amino acids could hardly be synthesized, some recent experimental and theoretical studies have suggested the existence of locally and transitionally reducing atmospheres that are generated by the impact of ordinary chondrites onto the early oceans. Such a reducing environment has the possibility to generate prebiotic organic materials.