ABSTRACT
In order to answer this question, we need to first ask why there are species in the first place. We cannot do that without investigating the origin of life itself.
21.2 Origin of life I Clearly we are alive. But when and where did life start? From fossil records, it is clear that life is surprisingly old. Indeed, the currently oldest known fossils are found in a fine-grained quartz called “chert”. Quartz consists mainly of silicon dioxide, the same molecule which is also the major constituent of glass. In the formation of chert, tiny quartz grains accumulated while trapping microbes. However, solidification only proceeded very slowly over thousands of years, such that rather than crushing the trapped microbes, the quartz crystals penetrated the cell walls of the microbes, preserving their three-dimensional structure.
