This is really cool. Amborella trichopoda, a flowering plant which is the only survivor in a line that existed alongside the ancestors of all other flowering plants, has had its genome sequenced.
Angiosperms sometimes duplicate their entire genome, a condition known as polyploidy. This can lead to the rather sudden development of an entirely new species. The new species is able to tinker with the genes in the second copy of the genome, because the original remains intact. (Strictly speaking, what I mean is that a mutation in one of the copies may not be harmful, even though it would have been if there had only been one copy. Even if the original mutation is nonfunctional, a subsequent mutation can create a novel trait.)
It should be no surprise that many of the genes common to Amborella are also found in non-flowering plants. Many genes in eukaryotes had their origin in prokaryotes.
But IMHO they are on shaky ground when they say:
The remaining 1,179 gene families—around a quarter of the total—were new. Some of these help to make flowers, but others are involved in stabilizing the plants’ physiology or responding to environmental cues, including plant-eating animals. “That was a surprise. The production of the flower wasn’t just a result of shifting gene expression, as is often assumed in the evolution of new development,” said dePamphilis. “There was a large amount of real novelty, too.”Unless a large proportion of the new genes are needed to produce flowers, I don't see much reason to believe that the production of flowers per se is the reason these genes evolved. The duplication in the genome would have given the lineage some freedom to evolve many new genes rapidly, as I explained above. This would allow for fairly rapid development of environmental adaptations not related to flower development.
Now of course it may be the case that my reading of the article as implying that only a small number of the genes were needed to produce flowers.
Anyway, very very cool stuff.
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