The greenery of Earth

The first plants to colonise the planet originated around 500 million years ago, much earlier than has previously been suggested by the fossil record, a new study has suggested.

Sea Lilly fossil
Sea Lilly fossil. Credit: Cardiff University

It’s been suggested that the first plant colonize the planet originated around 500 million years ago. The planet’s landmasses would have been without all life aside from microorganisms.

Now, all this changed with the origin of land plants from their pond scum relatives, greening the continents and creating habitats that animals would later invade.

A new research by the Cardiff scientists that shed light on this, suggested that these events occurred approximately eighty million years earlier. Through this finding, scientists could analyze the chemical weathering of continental rocks, a key process in the carbon cycle that regulates Earth’s atmosphere and climate over millions of years.

To land at their outcomes, the group utilized a ‘sub-atomic clock’ technique, which utilized confirmation on the hereditary make-up of living species to build up a developmental timescale that could fill in the holes of the fossil record.

The new outcomes now demonstrate that the mainland plants were alive in the center Cambrian time frame, a period amid which the principal has known earthbound creatures began to show up.

Co-lead author of the study Dr Jennifer Morris, from the School of Earth and Ocean Sciences, explained: “The global spread of plants and their adaptations to life on land during the Phanerozoic led to an increase in continental weathering rates that ultimately resulted in a dramatic decrease in the levels of greenhouse gases in the atmosphere.

“Previous attempts to model these changes in the atmosphere have accepted the plant fossil record at face value – our research shows that these fossil ages underestimate the timing of land plant evolution.  An earlier origin for land plants, therefore, could mean that the levels of greenhouse gases in the atmosphere at this time have been underestimated and so these models need to be revised.”