Genetic diversity is declining worldwide, but conservation action is proving effective in slowing its loss
The case of the Iberian lynx in Spain exemplifies how a species can lose genetic diversity and how conservation actions can improve its genetic status and reverse its decline

Some species, such as the Arctic fox, the golden bandicoot, and the Iberian lynx in Spain, are responding well to conservation efforts. Photo: Antonio Rivas
An international research team, with participation of the Doñana Biological Station – CSIC, has conducted the most temporally, spatially, and taxonomically comprehensive global analysis of genetic diversity ever undertaken. The study reveals 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, particularly where land use change, disease, abiotic natural phenomena and harvesting or harassment were reported.
‘Genetic diversity is essential to ensure the long-term survival of species. It provides the tools to tackle future conservation problems. This can be achieved, for example, by allowing adaptation to environmental changes - such as those associated with climate change - or by facilitating the fight against pathogens,’ explains Carles Vilà, a researcher at the Doñana Biological Station - CSIC and co-author of the study.
At the same time, the study show that 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’
The Iberian lynx, a successful case in Spain
Conservation management actions show promise in maintaining or even increasing genetic diversity, including supplementing new individuals into a population from elsewhere, population control to improve conditions for remaining individuals, improving environmental conditions through ecological restoration, and controlling feral and 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.
In Spain, a good example is the Iberian lynx, as José Antonio Godoy, a researcher at the Doñana Biological Station and also co-author of the study, explains: ‘The case of the Iberian lynx clearly illustrates how a species loses genetic diversity due to population decline. It also shows how conservation actions, including captive breeding and population reinforcement through translocations, can improve the genetic situation and reverse population decline. At the same time it highlights the need to detect the loss of diversity as early as possible in order to implement corrective management measures before it is too late’.
The authors hope the findings will encourage more conservation efforts and lead to increased protections for populations that are currently not managed. “This study shows that we need to increase investment in genetic monitoring programmes and ensure that our conservation strategies include specific actions to maintain genetic diversity, especially in threatened species and protected areas,’ concludes Jennifer Leonard, investigadora de la Estación Biológica de Doñana y coautora del estudio.
Reference
Shaw, Robyn E., Farquharson, K., et al., ‘Global meta-analysis shows action is needed to halt genetic diversity loss’ (Nature 2025) DOI: https://doi.org/10.1038/s41586-024-08458-x