When Earth was a lifeless planet about 4 billion years ago, chemical components came together in tiny molecular chains that would later evolve into proteins, which are crucial life building blocks. A new study has shown how some early predecessors of proteins may have fallen into line. Under laboratory conditions mimicking those on pre-life Earth, a small selection of amino acids linked up spontaneously into neat segments in a way that surprised Nicholas Hud at the Georgia Institute of Technology and colleagues.