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三、物质源:大气与土壤1.大气我们已经知道太阳系的外层行星带有含水分、甲烷、二氧化碳的大气层。这是一个化学还原系统,游离氧在其中是无法存在的。据信地球的原始大气层也曾是这样,它形成了一种富碳的环境,生命就是从这个环境中起源的,进化的第一步骤产生了微生物。微生物依靠就地的化学能源而生存(见前章图1),如果没有光合过程的生物化学进化,生物圈可能至今仍被一小撮碳素收支极低的化能营养微生物种所统治着。我们地球的表层和大气圈,对其中的有机体来讲,是一个并不宽敞的系统。这层富氧、穷碳的大气层,是光合作用所造成的。“宇宙
Third, the material source: the atmosphere and soil 1. Atmosphere We already know that the outer solar system planet with water, methane, carbon dioxide atmosphere. This is a chemical reduction system in which free oxygen can not exist. It is believed that the earth’s original atmosphere was once again that it formed a carbon-rich environment from which life originated, and the first step in evolution produced microbes. Microorganisms survive on the spot of chemical energy (see Figure 1 in the previous chapter). Without the biochemical evolution of the photosynthesis process, the biosphere may still be ruled by a handful of chemotrophic micro-organisms that have a very low carbon budget. The surface and atmosphere of our earth is a system that is not spacious for the organisms. This layer of oxygen-rich, poor carbon atmosphere, is caused by photosynthesis. "universe