Plants are DNA hoarders. Adhering to the maxim of never throwing anything out that might be useful later, they often duplicate their entire genome and hang on to the added genetic baggage. All those extra genes are then free to mutate and produce new physical traits, hastening the tempo of evolution.
A new study shows that such duplication events have been vitally important throughout the evolutionary history of gymnosperms, a diverse group of seed plants that includes pines, cypresses, sequoias, ginkgos and cycads. Published today in Nature Plants, the research indicates that a genome duplication in the ancestor of modern gymnosperms might have directly contributed to the origin of the group over 350 million years ago. Subsequent duplications provided raw material for the evolution of innovative traits that enabled these plants to persist in dramatically changing ecosystems, laying the foundation for a recent resurgence over the last 20 million years.
“This event at the start of their evolution created an opportunity for genes to evolve and create totally new functions that potentially helped gymnosperms transition to new habitats and aided in their ecological ascendance,” said Gregory Stull, a recent doctoral graduate of the Florida Museum of Natural History and lead author of the study.
Taking a closer look at gymnosperms
While having more than two sets of chromosomes — a phenomenon called polyploidy — is rare in animals, in plants it is commonplace. Most of the fruits and vegetables we eat, for example, are polyploids, often involving hybridization between