Resurrecting ancient genes: experimental analysis of extinct molecules

There are few molecular fossils: with the rare exception of DNA fragments preserved in amber, ice or peat, no physical remnants preserve the intermediate forms that existed during the evolution of today's genes. But ancient genes can now be reconstructed, expressed and functionally characterized, thanks to improved techniques for inferring and synthesizing ancestral sequences. This approach, known as 'ancestral gene resurrection', offers a powerful new way to empirically test hypotheses about the function of genes from the deep evolutionary past.