Flowering plants may have originated between 149 and 256 million years ago, says the findings of a study that was published on February 5, 2018.
Researchers found that flowering plants are neither as old as suggested by previous molecular studies, nor are they as young as a literal interpretation of their fossil record. In fact, the discrepancy between the estimates of flowering plant evolution from molecular data and fossil records has caused much debate.
The English naturalist, geologist and biologist, Charles Darwin, who is best known for his contributions to the science of evolution, also described the origin of this group as an 'abominable mystery'.
According to Jose Barba-Montoya, the lead author of the study, in order to uncover the key to solving the mystery of when flowers originated, they carefully analysed the genetic make-up of the flowering plants and the rate at which mutations accumulate in their genomes.
The researchers compiled a large collection of genetic data for many flowering plant groups including a dataset of 83 genes from 644 taxa, together with a comprehensive set of fossil evidence to address the timescale of flowering plant diversification.
• The fossil records reveal that the flowering plants diversified suddenly, precipitating a Cretaceous Terrestrial Revolution in which pollinators, herbivores and predators underwent explosive co-evolution.
• Molecular study however suggests a much older origin for flowering plants, implying a cryptic evolution of flowers that is not documented in the fossil record.
• The paleontological timescales calibrate the family tree of plants to geological time based on the oldest fossil evidence for its component branches.
• The molecular timescales build on this approach, using additional evidence from genomes for the genetic distances between species, aiming to overcome gaps in the fossil record.
The study was published in the journal New Phytologist.