Adaptive Reactions of Ancient Fossil Organisms: Likely Evolutionary Causes of Sociality Emergence

Abstract

The results of the study of stromatolites for the purposes of geology have shown the directed and irreversible nature of their evolution. Further detailed study of the structure made it possible to reveal the subordination of the structures of various hierarchical levels and the consistency of their changes over time, which indicates the presence of morphogenetic and adaptive capabilities in the macroscopic stromatolite-forming agent—the properties of an integral organism. This was in conflict with the ideas existing at that time about the impossibility of the formation of organized communities or multicellular organisms by prokaryotes. It was believed that the formation of multicellular organisms and any communities with developed communication requires a high structural complexity of the elements. Bacteria were considered as solitary or colonial organisms not having sufficient complexity. However, direct observation of their accumulations revealed signs of highly organized communities comparable in their integrity to organisms. This forces a different approach to the nature of the emergence of communities and the sources of their complexity. On the basis of the unity of the observed processes, in addition to the cyanobacteria themselves, data on other groups of bacteria, as well as on modular organisms and communities of multicellular eukaryotes, are considered.