RNA plays an essential role in biology by carrying genetic information from DNA and helping to synthesize proteins. It was discovered in the late 1950s that an intermediary RNA copy of a gene, called messenger RNA (mRNA), is required to translate genetic information stored in DNA into proteins. This established the central dogma of molecular biology whereby genetic information flows from DNA to RNA to protein. Some viruses also use RNA as their genetic material. Carl Woese later hypothesized that an "RNA world" may have existed before DNA and proteins, where RNA served both genetic and catalytic functions essential for life.