Our knowledge of evolution is filling in rapidly, thanks to a plethora of new techniques that enable a multi-pincer attack. Nick Lane is a biochemist, which gives him a different slant on a question that is usually considering entirely in terms of replicating molecules, ie DNA. The question of the evolution of life is not just a matter of reproduction and natural selection: the life process itself, bodies able to maintain them by the intake of energy is equally important. There has to be some energetically viable entity that can reproduce.
Lane thrillingly recounts Mike Russell’s theory that life evolved in the cold deep ocean where hot currents poured out from the churning mantle beneath. Biochemists have discovered that some of the essentially energetic reactions that now occurs in every cell are already present in these hot and cold chemical reactions in the deep ocean. This suggests that there are three requirements for life:
1) Cellular structures to contain the living material (this is the easy bit: such “cells” easily self-assemble from fatty substances
2) The aforementioned energy reactions that enable metabolism and motion
3) Self-replicating substances that can take over the running of the cell and its contents and allow the cell to reproduce itself.
Life, we have discovered, is modular, with functions bolted on to existing ones. There is no reason to suppose that the very beginning was any different: these three processes combining to create the cell, which could then undergo Darwinian evolution as we know it.
Lane’s 10 inventions are: the first life itself; DNA; photosynthesis; The Complex Cell; Sex; Movement; Sight; Hot Blood; Consciousness; Death. This single book will set the reader off on many exciting trails. What was once mostly speculation is now becoming hard science.