Step aside, DNAnew synthetic compounds called XNAs can also store and copy genetic information, a new study says.

And, in a "big advancement," these artificial compounds can also be made to evolve in the lab, according to study co-author John Chaput of the Biodesign Institute at Arizona State University. (See "Evolution vs. Intelligent Design: 6 Bones of Contention.")

Nucleotides, the building blocks of DNA are composed of four basesA, G, C, and T. Attached to the bases are sugars and phosphates. (Get a genetics overview.)

First, researchers made XNA building blocks to six different genetic systems by replacing the natural sugar component of DNA with one of six different polymers, synthetic chemical compounds.

The teamled by Vitor Pinheiro of the U.K.'s Medical Research Council Laboratory of Molecular Biologythen evolved enzymes, called polymerases, that can make XNA from DNA, and others that can change XNA back into DNA.

This copying and translating ability allowed for genetic sequences to be copied and passed down again and againartificial heredity.

Last, the team determined that HNA, one of the six XNA polymers, could respond to selective pressure in a test tube.

As would be expected for DNA, the stressed HNA evolved into different forms.

This shows that "beyond heredity, specific XNAs have the capacity for Darwinian evolution," according to the study, published tomorrow in the journal Science. (Read "Darwin's Legacy" in National Geographic magazine.)

"Thus, heredity and evolution, two hallmarks of life, are not limited to DNA and RNA."

The rest is here:
Synthetic DNA Created, Evolves on Its Own