The evolution of flowers
BY LOOKING AT more than 800 flowering plant species scientists from the eFLOWER Project have managed to create a digital model of what the first flower may have looked like.
After emerging 140 million years ago, during the late Jurassic, flowering plants (angiosperms) quickly became the most diverse plants on Earth. There are now estimated to be more than 300,000 species, yet little is known about the group’s evolution.
Now, eFLOWER, an international research project dedicated to combining information on flower structure with DNA-based evidence on the evolution of flowering plants, has brought to light new information on an evolutionary mystery.
The database of floral features was collated and analysed over six years by an international team of researchers, including University of Sydney PhD student Charles Foster.
The project’s head researcher, evolutionary biologist and botanist Hervé Sauquet from Université Paris-Sud in France, explained that the digital flower model that resulted from the information looks similar to modern-day magnolias and does not reflect previous ideas of what the first flowering plant looked like.
“When we finally got the full results, I was quite startled until I realised that they actually made good sense,” he said. “No one has really been thinking about the early evolution of flowers in this way, yet so much is easily explained by the new scenario that emerges from our models.”
Most importantly the study revealed that the first flower had both female and male parts, in addition to multiple circular cycles of petal-like organs, in sets of threes. Prior to this finding it was believed that the first flower had all organs arranged in a spiral.
The researchers managed to reconstruct what certain flowers looked like at all the key points in the flowering plant evolutionary tree, including changes within the structure of the group known as monocots which includes orchids and lilies, as well as the eudicots including poppies, roses, and sunflowers.
However, the researchers explained that our understanding of the evolution of flowering plants still contains major gaps as the database remains incomplete without fossils dating back to the period in which flowers first emerged.
All living flowers ultimately derive from a single ancestor (pictured in the centre) that lived about 140 million years ago. (Image Credit: Hervé Sauquet & Jürg Schönenberger)