Scientists decode origin of flowers

London: A team of scientists from Britain and China has claimed to have solved what Charles Darwin called the "abominable mystery" of when flowers originated. Flowering plants likely originated between 149 and 256 million years ago, said the study published in the journal New Phytologist.

The study shows that flowering plants are neither as old as suggested by previous molecular studies, nor as young as a literal interpretation of their fossil record. "The discrepancy between estimates of flowering plant evolution from molecular data and fossil records has caused much debate. Even Darwin described the origin of this group as an 'abominable mystery'," explained lead author Jose Barba-Montoya from University College London. 

"To uncover the key to solving the mystery of when flowers originated, we carefully analysed the genetic make-up of flowering plants, and the rate at which mutations accumulate in their genomes," he explained. Through the lens of the fossil record, flowering plants appear to have diversified suddenly, precipitating a Cretaceous Terrestrial Revolution in which pollinators, herbivores and predators underwent explosive co-evolution.

Molecular-clock dating studies, however, have suggested a much older origin for flowering plants, implying a cryptic evolution of flowers that is not documented in the fossil record. "In large part, the discrepancy between these two approaches is an artefact of false precision on both palaeontological and molecular evolutionary timescales," said Professor Philip Donoghue from the University of Bristol in England.

The new findings underline the power of using complementary studies based on molecular data and the fossil record, along with different approaches to infer evolutionary timescales to establish a deeper understanding of evolutionary dynamics many millions of years ago.