Recent research reveals a striking correlation to how life evolved over 500 million years.
The movement of rivers, mountains, oceans, and sediment nutrients at the geological timescale are central drivers of Earth’s biodiversity, new research recently published in Nature reveals. The research also shows that biodiversity evolves at rates similar to the pace of plate tectonics, the slow geological processes shaping continents, mountains, and oceans.
“That is a rate incomparably slower than the current rates of extinction caused by human activity,” said lead author Dr Tristan Salles from the School of Geosciences.
The research looks back over 500 million years of Earth’s history to the period just after the Cambrian explosion of life, which established the main
The discovery in 1994 of the ancient Wollemi pine species in a secluded valley in the Blue Mountains west of Sydney gives us a glimpse into the holistic role that time, geology, hydrology, climate and genetics play in biodiversity and species survival.
Historical Perspective on Landscapes and Life
The idea that landscapes play a role in the trajectory of life on Earth can be traced back to German naturalist and polymath Alexander von Humboldt. His work inspired Charles Darwin and Alfred Wallace, who were the first to note that animal species boundaries correspond to landscape discontinuities and gradients.
“Fast forwarding nearly 200 years, our understanding of how the diversity of marine and terrestrial life was assembled over the past 540 million years is still emerging,”
“It is through calibration of this physical memory etched in the Earth’s skin with genetics, fossils, climate, hydrology, and tectonics by which we have investigated our hypothesis,” Dr Salles said.
Using open-source scientific code published by the team in Science in March, the detailed simulation was calibrated using modern information about landscape elevations, erosion rates, major river waters, and the geological transport of sediment (known as sediment flux).
Comparing Predictions and Paleontological Data
This allowed the team to evaluate their predictions over 500 million years using a combination of geochemical proxies and testing different tectonic and climatic reconstructions. The geoscientists then compared the predicted sediment pulses to the evolution of life in both the marine and terrestrial realms obtained from a compilation of paleontological data.
“In a nutshell, we reconstructed Earth landforms over the Phanerozoic era, which started 540 million years ago, and looked at the correlations between the evolving river networks, sediment transfers and known distribution of marine and plant families,” University of Grenoble PhD student Manon Lorcery said.
When comparing predicted sediment flux into the oceans with marine biodiversity, the analysis shows a strong, positive correlation.
On land, the authors designed a model integrating sediment cover and landscape variability to describe the capacity of the landscape to host diverse species. Here again, they found a striking correlation between their proxy and plant diversification for the past 450 million years.
In his 1864 novel A Journey to the Centre of the Earth, Jules Verne attributes this to his fictitious hero, Professor Otto Lidenbrock: “Animal life existed upon the Earth only in the secondary period, when a sediment of soil had been deposited by the rivers and taken the place of the incandescent rocks of the primitive period.”
Dr Salles said: “This observation by Professor Lidenbrock to his nephew Axel fits strikingly well with our hypothesis. So, it should be no surprise that Jules Verne was greatly inspired by Humboldt’s work.”
Reference: “Landscape dynamics and the Phanerozoic diversification of the biosphere” by Tristan Salles, Laurent Husson, Manon Lorcery and Beatriz Hadler Boggiani, 29 November 2023, Nature.
DOI: 10.1038/s41586-023-06777-z
This research was undertaken with resources from the National Computational Infrastructure supported by the Australian Government and from Artemis HPC supported by the University of Sydney. The study was funded by the Australian Research Council.