Arabidopsis thaliana, pollinates itself--an ability that new research suggests it acquired relatively recently in its evolutionary history. Arabidopsis has the same genes that in cross-pollinating plants discourage self-pollination, but they have been rendered nonfunctional. Writing in the current issue of Science, researchers report that the sequence diversity in these so-called pseudogenes is rather lower than that observed in the active counterparts on cross-pollinating plants, indicating that Arabidopsis evolved self-compatibility--and the associated changes in flower shape, for example--only after 11,000 years ago or so. The image above shows Arabidopsis pollen-pistil interactions, with the pollen tubes growing toward ovules.