A coherent pathway which starts from no more than rocks, water and carbon dioxide and leads to the emergence of the strange bio-energetic properties of living cells, has been traced for the first time in a major hypothesis paper in Cell this week.
At the origin of life the first protocells must have needed a vast amount of energy to drive their metabolism and replication, as enzymes that catalyse very specific reactions were yet to evolve. Most energy flux must have simply dissipated without use.
So where did it all that energy come from on the early Earth, and how did it get focused into driving the organic chemistry required for life?
The answer lies in the chemistry of deep-sea hydrothermal vents. In their paper Nick Lane (UCL, Genetics, Evolution and Environment) and Bill Martin (University of Dusseldorf) address the question of where all this energy came from - and why all life as we know it conserves energy in the peculiar form of ion gradients across membranes.
this has always been the most vexing question to me and the hardest to answer to my students. While i believe life spontaneously arose on earth through chemical means, its hard to say that to deeply conservative teens with a straight face and expect them to buy it. "It just DID, trust me" isnt a very convincing argument. If people are to accept spontaneous generation of life, scientists must propose and demonstrate a valid method for it to occur.