Flexi Says: Scientists are still studying the origins of DNA. Life on Earth has used DNA to carry genetic information for over 3 billion years. Scientists once assumed that the earliest cells may have used simpler, single-stranded RNA, and then switched to the more stable DNA over time. However, newer studies show that DNA molecules can arise by chemical reactions in some abiotic environments outside of living cells. This discovery has led scientists to question whether DNA molecules may have preceded the evolution of cellular life.
