Molecule sparks origin-of-life debate

What were the first genes made of? Many investigators believe that life’s initial genetic material was ribonucleic acid (RNA) instead of its current choice, deoxyribonucleic acid (DNA) (SN: 5/6/95, p. 279). While evidence for this RNA-world hypothesis has grown, some scientists have questioned whether nucleic acids with a backbone of ribose, or any other sugar molecule, would be stable enough to survive the harsh conditions of early Earth.