For 140 years, scientists have been trying to explain what Charles Darwin described as “an abominable mystery”.
Darwin was bothered by evidence suggesting the sudden occurrence of angiosperms – seed-producing flowering plants – in the mid-Cretaceous period. The evidence rather flew in the face of his theory of evolution, which implied that all organisms should increase gradually. “Natura non facit saltum,” he wrote. Nature does not make a leap.
Earlier this year, as reported in Cosmos, a US-led team suggested the answer lies in the ability of these plants to downsize their genomes, giving them the infrastructure and energy to spread rapidly.
Now Chinese researchers have suggested it’s a question of timing of a rather different nature.
Writing in the journal Scientific Reports, a group led by Wang Xin from the Nanjing Institute of Geology and Palaeontology describe a flower, Lijinganthus revoluta, found embedded in Burmese amber dating to 99 million years ago.
The fossil is exquisite and complete and, most importantly, belongs to the Pentapetalae clade of core eudicots – a large and diverse assemblage of angiosperms found in a range of habitats.
Together with contemporaneous flowers and fruits, the researchers say, Lijinganthus indicates that core eudicots flourished on Earth about 100 million years ago, although did not dominate vegetation until about 20 million years later, the mid-Cretaceous.
“Various molecular clocks indicate that angiosperms and eudicots have a significantly earlier origin than the earliest fossil record indicates,” the authors write.
In other words, they suggest, what Darwin thought was the origin of angiosperms was, in fact, a blooming that was millennia in the making.
Nick Carne is the editor of Cosmos Online and editorial manager for The Royal Institution of Australia.
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