In the most comprehensive global analysis of genetic diversity ever undertaken, an international team of scientists has found that the genetic diversity is being lost across the globe but that conservation efforts are helping to safeguard species.
The landmark study, published in the pre-eminent scientific journal Nature , was led by Associate Professor Catherine Grueber from the School of Life and Environmental Sciences and a team of researchers from countries including the UK, Sweden, Poland, Spain, Greece and China.
The data spans more than three decades (from 1985-2019) and looks at 628 species of animals, plants and fungi across all terrestrial and most maritime realms on earth.
Two-thirds of the populations analysed are declining in genetic diversity but conservation efforts designed to improve environmental conditions, grow populations and introduce new individuals for breeding – for example habitat restoration and animal translocations – are sustaining, and in some cases increasing, genetic diversity in populations.
Associate Professor Grueber said: "There is no getting around the fact that biodiversity is declining at unprecedented rates across the globe – but there are glimmers of hope. The action of conservationists is reversing these losses and helping to create genetically diverse populations that can better meet the challenges of the future."
The team of scientists used innovations in genetic analysis to gain new insights from studies carried out decades ago. Creating a common measurement scale, they were able to make comparisons between studies, even when they used different methodologies and collected genetic data in different ways.
"This kind of comprehensive global study would not have been possible even 10 years ago," Associate Professor Grueber said.
"Advances in genetics and statistics have given us new tools that mean we can continue to learn from studies long after they were carried out – a huge benefit when we are looking at populations and trends on a global scale."
Conservation efforts that could improve or maintain genetic diversity include translocations – where animals are moved between populations to benefit a species or ecosystem – habitat restoration, population control – where some individuals are removed to improve conditions for those that remain – and controlling feral or pest species.
Successes include the reintroduction of the golden bandicoot into areas in Western Australia , the release of arctic foxes from captive breeding programs in Scandinavia, translocation of greater prairie chickens into existing populations in North America, and the effective treatment of disease within black-tailed prairie dog populations , which has improved the health of colonies in north-central Montana in the US.
The authors hope the findings will encourage more conservation efforts and lead to increased protections for populations that are currently not managed.
Co-first author, Dr Robyn Shaw from the University of Canberra, said: "Despite successes, we can't be complacent. Two-thirds of the populations analysed are facing threats, and among these populations less than half received any kind of conservation management. It's vital that we learn from what is working so that we can protect species in the long-term."
