Lahav N, Chang S
J Mol Evol. 1976 Dec 30;8(4):357-80. doi: 10.1007/BF01739261.
Published data on adsorption and condensation of amino acids, purine and pyrimidine bases, sugars, nucleosides, and nucleotides are analyzed in connection with Bernal's hypothesis that clays and other minerals may have provided the most likely surface for adsorption and condensation of these molecules in prebiotic times. Using surface concentration and reaction rate as the main criteria for the feasibility of condensation reactions, four types of prebiotic environments were analyzed: (1) an ocean-sediment system, (2) a dehydrated lagoon bed produced by evaporation, (3) the surface of a frozen sediment, and (4) a fluctuating system where hydration (rainstorms, tidal variations, flooding) and dehysration (evaporation) take place in a cyclic manner. With the possible exception of nucleotides, low adsorption of organomonomers on sediment surfaces of a prebiotic ocean (pH 8) is expected, and significant condensation is considered unlikely. In dehydrated and frozen systems, high surface concentrations are probable and condensation is more likely. In fluctuating environments, condensation rates will be enhanced and the size distribution of the oligomers formed during dehydration may be influenced by a "redistribution mechanism" in which adsorbed oligomers and monomers are desorbed and redistributed on the solid surface during the next hydration-dehydration cycle.
已发表的关于氨基酸、嘌呤和嘧啶碱基、糖类、核苷和核苷酸的吸附与缩合的数据，是结合伯纳尔的假说进行分析的。该假说认为，在生命起源之前的时期，黏土和其他矿物质可能为这些分子的吸附和缩合提供了最有可能的表面。以表面浓度和反应速率作为缩合反应可行性的主要标准，分析了四种类型的生命起源前环境：（1）海洋 - 沉积物系统，（2）由蒸发产生的脱水泻湖床，（3）冷冻沉积物的表面，以及（4）一个波动系统，其中水合作用（暴雨、潮汐变化、洪水）和脱水作用（蒸发）以循环方式发生。除了核苷酸可能是个例外，预计在生命起源前海洋（pH 8）的沉积物表面有机单体的吸附较低，并且认为显著的缩合不太可能发生。在脱水和冷冻系统中，高表面浓度是可能的，缩合更有可能发生。在波动环境中，缩合速率将会提高，并且在脱水过程中形成的低聚物的尺寸分布可能会受到一种“重新分布机制”的影响，在这种机制中，吸附的低聚物和单体在接下来的水合 - 脱水循环中会解吸并在固体表面重新分布。
