ApharmdB (572578) writes "DNA & RNA are the basic building blocks of life. But could there be alternatives? Scientists have created HNA, CeNA, LNA, ANA, FANA and TNA in the lab. That is allowing for exploration of numerous questions such as 'What is the origin of DNA & RNA?' The journal article can be found here." Link to Original Source
You see but you do not observe.
Sir Arthur Conan Doyle, in "The Memoirs of Sherlock Holmes"