By swapping out the sugar molecules that put the D in DNA, scientists have created new hereditary molecules that can undergo Darwinian evolution.
Making the six new molecules, collectively called XNAs, is a major technological advance that could lead to all sorts of new drugs, sensors and diagnostic devices. The research, reported in the April 20 Science, could also provide clues to how life evolved on Earth.
“What makes DNA and RNA so cool is they are the genetic molecules, they are the basis for propagating information through generations,” says biochemist Gerald Joyce of the Scripps Research Institute in La Jolla, Calif. “Well, we now have eight genetic molecules: RNA, DNA and these six.”
While just creating the XNAs (for xenonucleic acids) represents a feat in itself, the molecules can’t do the entire evolution thing on their own: DNA still lends a hand at the replication stage. But the work is a step towards an alternative kind of life and as such is “a wonderful achievement,” says Joyce, author of a commentary on the work in the same issue of Science.