Landmark genetic study: Fresh shoots of hope on the tree of life

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.”

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Download images of the researchers and case study animals at this link.

Case study animals

Further information about the species mentioned in the study, which have seen an increase in genetic diversity thanks to conservation actions. More examples are available from researchers.

• Golden bandicoot (Isoodon auratus): an Australian threatened species, where genetic diversity was successfully maintained when establishing new populations in Western Australia.
• Scandinavian arctic fox (Vulpes lagopus): the species has seen huge declines due to the fur trade. It now has smaller population sizes and faces competition from red foxes, among other threats. A range of conservation actions are being used, including supplementary feeding, the removal of red foxes and release of arctic foxes from captive breeding programs. These efforts have seen the maintenance of – and in some cases an increase in – genetic diversity, helping the population size to grow.
• Black-tailed prairie dog (Cynomys ludovicianus): in the wild this species suffers from plague, which is spread by fleas. By dusting prairie dog burrows with an insecticide to control fleas, conservationists observed an improved gene flow and an increase in genetic diversity, improving the outlook for the population.
• Greater prairie chicken (Tympanuchus cupido pinnatus): conservation efforts to translocate animals amongst sites and restore habitat have increased genetic diversity and reduced inbreeding, improving the prospects for these populations.
• Hine’s emerald dragonfly (Somatochlora hineana): an endangered US species which has declined and become fragmented due to habitat loss. Ongoing intensive management efforts to maintain habitat and reconnect habitat patches are helping the species maintain genetic diversity and are expected to help population sizes to grow.
• Dusky gopher frog (Lithobates sevosus): a critically endangered species from Mississippi, which has very small population and low genetic diversity. These are increasing thanks to conservation efforts, such as “headstarting” (growing tadpoles in tanks), as well as managing wetlands and fire risks within the landscape.

Interviews 

Associate Professor Catherine Grueber | catherine.grueber@sydney.edu.au

Media enquiries

Marcus Strom | marcus.strom@sydney.edu.au | +61 474 269 459

Research

Shaw, Robyn E., Farquharson, K., et al., ‘Global meta-analysis shows action is needed to halt genetic diversity loss’ (Nature 2025) DOI: 10.1038/s41586-024-08458-x

Declaration: The researchers declare no conflicts. Funding was received, inter alia, from the University of Sydney Robinson Fellowship, the Australian Research Council, European Union, Croatian Science Foundation, Uppsala University, Institute of Nature Conservation, Polish Academy of Science, Swedish Research Council, Dutch Ministry of Agriculture, Slovenian Research and Innovation Agency, Italian Ministry of University and Research

For a full list of funders, see the published paper.

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