Rapid evolutionary innovation during an Archaean genetic expansion and there is also a commentary on the paper: Evolution: Old genes
During the Great Oxidation Event about 2.4 billion years ago, the
surface of the Earth tipped irrevocably into an oxygenated state, as
free molecular oxygen began to accumulate in the oceans and atmosphere.
But the first whiffs of oxygen began to appear at least 300 million
years earlier, as organisms capable of producing the gas through
photosynthesis evolved. As the Earth's chemistry changed, so too must
have the microbes that lived on its surface. But the rock record leaves
only hints of the ecosystem, primarily in the form of isotopic
fractionation of the elements — including iron and sulphur — that
presumably fuelled the bacteria.
To assess the evolution of these
metabolisms, Lawrence David and Eric Alm of the Massachusetts Institute
of Technology looked to the genetics of extant organisms. They
re-examined existing gene families using a technique that accounts for
both the evolution of new genes, and the transfer of genes between
The paper is interesting not just because of the results but because it
gives you an insight into the techniques you need to use to address
these sorts of questions.