The professor of Bioquímica of the University of Valencia, Juli Peretó, and member of the Institute of Systems Integrative Biology, talks about an exciting subject that has interested thinkers of all time: how life was originated on Earth . Peretó explains the transition between geochemistry, planetary chemistry, and biochemistry, the chemistry of living beings. A transition that took place more than 4,000 million years ago and that occurred on a very different planet, little hospitable, but that would be the birthplace of the complex chemistry that we call "life."