Evolution by natural selection is one of the central pillars of biology, explaining the amazing biodiversity observed on Earth and how species change over time. One of the aspects of evolution scientists are still learning about is how quickly these processes have been occurring in recent times. A new study using many disparate datasets and evolution models run on the NCI supercomputer has tried to answer these questions. It has found that evolution over the last decades may on average be taking place 2 to 4 times faster than previously thought.
The study was led by Dr Timothée Bonnet from The Australian National University (ANU), as part of an international team of researchers spanning 12 countries. In contrast to previous studies, this collaborative effort enabled the current speed of evolution by natural selection to be assessed on a large scale, across multiple species.
The international research team drew on extensive observational data from studies of 19 different wild animal populations around the world, including Australia’s own superb fairy-wren. Each of these intergenerational studies included detailed life history information at the individual level: when and where an animal was born, as well as its mating history, offspring and eventual death.
By comparing this wealth of life event data with genetic information, researchers were able to build computational models to quantify how much species change was occurring due to genetic changes caused by natural selection. This approach unlocked the full value of extensive and rich field observations: studies ran for an average of 30 years and comprised data collected over 2.6 million hours of field work.
The computational power required to develop and run these models was provided by NCI’s Gadi supercomputer located at ANU. “While the project may not be big by supercomputing standards, the research would not have been possible without our allocated computing time on Gadi”, Dr Bonnet said.
“Firstly, it was critical to enable analysis of the data on different animal populations. Some of the datasets are large, and complex methods are involved, requiring a lot of time to run models and to confirm and optimise results. Secondly, Gadi also enabled us to run simulations to confirm we were appropriately taking into account all variables in our model. This gave us confidence in our findings.”
Dr Bonnet and the team arrived at some intriguing results, with their analysis providing evidence that natural selection contributed to rapid genetic changes in approximately half of the animal populations assessed. This has clear implications for how species are equipped to adapt to changes in their environment, suggesting that evolution should not be completely discounted as a process that can support species to respond to environmental changes. While this may mean populations are more resilient to changes than previously assumed, Dr Bonnet and team are careful to note there are no guarantees that populations will be able to keep up with the pace of any environmental changes encountered.
The research paper Genetic variance in fitness indicates rapid contemporary adaptive evolution in wild animals, published in Science, is available here.
Read the ANU media release “Fuel of evolution” more abundant than previously thought in wild animals here.