Black smokers, hotbeds for life (Image: Charles Fisher/NSF Ridge 2000 programme)

IN THE beginning there were Ida and Luca. The initial Darwinian ancestor – Ida – and the last universal common ancestor – Luca – assembled themselves from the spare parts sloshing around on the early Earth. Once all the ingredients were in place, it looks like life was all but inevitable.

The finding comes from recent discoveries about the behaviour of chemicals thought to have been present on the primordial Earth, relating to two key stages in the evolution of life. Ida was the first molecule that was able to self-replicate. Once it …