Des Marais D J
NASA Ames Research Center, Moffett Field, CA 94025, USA.
Trends Ecol Evol. 1990 May;5(5):140-4. doi: 10.1016/0169-5347(90)90219-4.
Microbial mats have descended from perhaps the oldest and most widespread biological communities known. Mats harbor microbes that are crucial for studies of bacterial phylogeny and physiology. They illustrate how several oxygen-sensitive biochemical processes have adapted to oxygen, and they show how life adapted to dry land long before the rise of plants. The search for the earliest grazing protists and metazoa in stromatolites is aided by observations of mats: in them, organic compounds characteristic of ancient photosynthetic protists can be identified. Recent mat studies suggest that the 13C/12C increase observed over geological time in stromatolitic organic matter was driven at least in part by a long-term decline in atmospheric carbon dioxide levels.
微生物席可能起源于已知最古老、分布最广泛的生物群落。微生物席中蕴藏着对细菌系统发育和生理学研究至关重要的微生物。它们展示了一些对氧气敏感的生化过程是如何适应氧气的，还表明早在植物出现之前生命就已适应了陆地环境。对叠层石中最早的食草原生生物和后生动物的探寻因对微生物席的观察而得到助力：在微生物席中，可以识别出古代光合原生生物特有的有机化合物。最近对微生物席的研究表明，在地质时期叠层石有机质中观察到的13C/12C增加至少部分是由大气二氧化碳水平的长期下降所驱动的。
