Genome downsizing, physiological novelty, and the global dominance of flowering plants

In this paper published in the current issue of Plos Biology, the authors support a hypothesis as to why flowering angiosperms were able to become so prominent. The authors make the argument that during the cretaceous period, angiosperm lineages went through a period of rapid genome downsizing. This downsizing of their genome allowed for a reduction of the size of the nucleus and subsequently a shrinking of the entire cell. Doing so allowed angiosperms to have more veins and stomata in their stems allowing for more productivity in the leaves. Effectively the argument boils down to a decrease in genome size facilitated more energy efficient and productive cells that allowed for angiosperms to compete against the already dominant non flowering taxa.

 Visualization of Genome size by taxon

- Louis Gorgone