First ecosystems on Earth

Theories attempting to explain the origin of life on Earth should be based on the assumption that habitability precedes habitation. The hypotheses of the first organism should be based on the evaluation of its possible life-supporting ecosystem. The ecosystem should necessarily include primary autotrophic producers, and hydrogenotrophy appears to be an adequate physiological type for primitive ecosystems. Consideration of life on Earth should differentiate between the origin of organisms in situ and the transportation of organisms from outside with cosmic bodies in the framework of life as a widespread phenomenon of the Universe. In the case of transport of life with cosmic bodies, there are no limitations on the transfer of a community rather than an individual cell. In the case of the transport of the community with a large piece of “dirty ice,” the problem lies in the correspondence between the community and its ecosystem on the parent body and the conditions on the primeval Earth rather than functional divergence from a primary ancestor. Subsequent events are within the framework of paleontologically observed evolution and can be described as biogeochemical succession without any additional speculations.