What Did the Ancestor of All Flowers Look Like?
Tracing back the genetic tree of flowering plants millions of years, scientists recreate the predecessor of Earth’s flowers
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Some 140 million years ago, when dinosaurs ruled the Earth, the ancestor of all flowering plants likely blossomed. But their delcate forms aren't easily preserved, leaving scientists wondering: What did these first blooms look like?
Now, using some genetic detective work, scientists have recreated one possibility. And it looks vaguely like a magnolia.
"This is the first time that we have a clear vision for the early evolution of flowers." study co-author Maria von Balthazar tells told Doyle Rice of USA Today. The oldest fossilized records of flowering plants, also known as angiosperms, that scientists have found so far date back 130 million years ago, reports Patrick Monahan for Science, which is roughly 10 million years after scientists believe the flower's ancestor first bloomed.
“We almost know nothing about how flowers evolved since their origin and yet this is extremely important for their ecological role and the role that plants play today on Earth,” biologist Hervé Sauquet tells Nicola Davis of the Guardian. So instead of seeking out more fossils, Sauquet and his colleagues decided to try to recreate the common ancestor of all flowers with the power of DNA.
Drawing on a database of scientific research on hundreds of modern flowers, Sauquet's team plotted backwards on a DNA family tree of angiosperms, reports Monahan. They tested millions of possible shapes and forms for a flower that would likely evolve into the flowers we know today.
What resulted was a flower that looks similar to a magnolia, but resembles no modern flower exactly, reports Monahan. It contains the petals, carpels and stamens you would find in any modern flower, but those parts were arranged in a circular formation of "whorls," not the spiral formation found in some of the oldest existing flower species. They published their results this week in the journal Nature Communications.
"These results call into question much of what has been thought and taught previously about floral evolution," co-author Juerg Schoenenberger of the University of Vienna tells Rice. "It has long been assumed that the ancestral flower had all organs arranged in a spiral."
Though whorls are found in many modern flowers, this simulated ancestral flower had more whorls than normally seen. Scientists speculate that evolution might have gradually reduced the number of whorls found on most flowers to help make pollination easier, reports Davis, but they're not certain of this just yet.
As botanist Beverley Glover, who was not involved in the study, tells Davis: “Working out why this might have happened will keep us scratching our heads for some time.”