Author(s): Carl Zimmer

Popular Science

In 1946, a twenty-year-old medical school student called Joshua Lederberg decided to find out whether microbes make love. Lederberg was motivated not by a displaced libido, but by scientific ambition. At the age of seven, he had declared that he hoped to become 'like Einstein' and to 'discover a few things in science.' The 'few things' Lederberg discovered would revolutionise modern science and earn him a Nobel Prize. He chose to observe the breeding habits of a certain bacterium called Escherichia coli, better known as E coli. His experiments used defective E coli strains lacking the essential molecules to reproduce by cloning which should, by rights, perish in the petri dish.But slowly, a few colonies of survivors began to spread across the dishes. The only possible explanation for their survival was that they were a product of sex. Not only had Lederberg proved that bacteria have sex, he had also proved they have genes. Since then, a bacterium that was once nothing more than a humble resident of the human gut has become our best guide to what it means to be alive.