Flowering plants may be considerably older than previously thought, says a new analysis of the plant family tree.
Previous studies suggest that flowering plants, or angiosperms, first arose 140 to 190 million years ago. Now, a paper to be published in the Proceedings of the National Academy of Sciences pushes back the age of angiosperms to 215 million years ago, some 25 to 75 million years earlier than either the fossil record or previous molecular studies suggest.
“If you just looked at the fossil record, you would say that angiosperms originated in the early Cretaceous or late Jurassic,” said Michael Donoghue of Yale University. “Most molecular divergence times have shown that they might be older than that,” added Yale biologist Jeremy Beaulieu. “But we actually find that they might be Triassic in origin,” said Beaulieu. “No one has found a result like that before.”
If confirmed, the study could bolster the idea that early angiosperms promoted the rise of certain insects. Modern insects like bees and wasps rely on flowers for nectar and pollen. “The fossil record suggests that a lot of these insect groups originated before angiosperms appeared,” said Stephen Smith of the National Evolutionary Synthesis Center. This study shifts the oldest angiosperms back farther in time towards the origin of groups like bees and flies, the scientists say. “If you take our dates and superimpose them on the evolutionary tree for these insect groups, all of a sudden you get a match,” said Beaulieu.