Research spanning over three decades (1985 to 2019) reveals a significant decline in genetic diversity across 628 species of animals, plants, and fungi globally. The study, published in the journal Nature, indicates that two-thirds of the populations examined are experiencing a decrease in genetic diversity.
According to the study, factors such as habitat destruction and the introduction of invasive species contribute to this decline, leading to reduced genetic variation within species, which threatens their adaptability and long-term survival.
Led by Catherine Grueber from the University of Sydney, the research team conducted a systematic review of 882 studies assessing changes in genetic diversity. They found that the majority of losses occurred in terrestrial species (90.2% of the dataset), with birds and mammals showing the most significant reductions in genetic variation.
Despite the alarming trends, the authors noted some positive outcomes. Conservation efforts, particularly the supplementation of populations with new individuals, have shown to increase genetic diversity over time. However, less than half of the affected populations have received conservation management.
Grueber emphasizes the importance of targeted conservation actions to mitigate genetic diversity loss, stating, "The action of conservationists is reversing these losses and helping to create genetically diverse populations better able to face future challenges." Successful examples of conservation include the reintroduction of the golden bandicoot in Western Australia and effective disease management in black-tailed prairie dog populations in Montana, USA.
The study also highlights the Iberian lynx as an example of how conservation actions, such as captive breeding and population reinforcement, can enhance genetic diversity and counter demographic decline.
Researchers from the UK, Sweden, Poland, Spain, Greece, and China contributed to this study, underscoring the global nature of the issue and the need for enhanced conservation efforts.