A comprehensive study published in the journal Nature has revealed a significant decline in genetic diversity among animals and plants globally over the past three decades. The analysis, which examined more than 600 species, found that two-thirds of the populations studied experienced genetic diversity losses. However, the study also highlighted that urgent conservation efforts could potentially halt or even reverse these declines.
Comprehensive Analysis and Findings
The research team, composed of dozens of international scientists, reviewed 882 studies measuring genetic diversity changes between 1985 and 2019 in 628 species of animals, plants, fungi, and chromists (a type of organism). This extensive review has been described as “the most comprehensive investigation” of changes in genetic diversity within species to date.
Assoc. Prof. Catherine Grueber of the University of Sydney, the study’s lead researcher, emphasized the importance of within-species diversity, which refers to the variation between individuals of the same species. “If a new disease comes through, or there’s a heatwave, there may be some individuals in the population that have certain characteristics that enable them to tolerate those new conditions,” Grueber explained. These characteristics can be passed on to future generations, allowing the population to persist instead of going extinct.
Causes of Genetic Diversity Loss
The study identified several leading causes of genetic diversity loss, which are also responsible for population declines. These include habitat loss, climate change, invasive species, and new diseases. The researchers found ecological disturbances in 65% of the populations studied, including human harvesting, harassment, and changes in land use. Interestingly, genetic diversity loss occurred even in the absence of reported disturbances, indicating a “background level of genetic diversity loss across species.”
Despite the grim findings, the study also showcased instances where tailored conservation strategies successfully improved genetic diversity. For example, in Western Australia, a project to establish new populations of golden bandicoots—a threatened species—managed to maintain genetic diversity through careful selection and monitoring.
In the United States, conservation biologists preserved genetic variability in black-tailed prairie dogs by using insecticides to prevent fleas from spreading the plague during an outbreak. This allowed the populations to thrive and interbreed with other prairie dogs.
In Scandinavia, arctic fox populations, which had declined due to the fur trade and competition with red foxes for prey, saw increases in genetic diversity thanks to supplementary feeding and the removal of red foxes.
Grueber stressed the significance of preserving genetic diversity in natural systems. “It’s important that we preserve the genetic diversity of our natural systems,” she said. “We have the methods to make it work.” The meta-analysis included species from 141 countries, with more than 500 animal species represented.
Maintaining genetic diversity in wild and domesticated species was identified as a key component of one of the goals adopted at the biodiversity conference Cop15 in 2022. The study’s findings underscore the broader effects of ecological disruptions, such as climate change, on the planet’s biodiversity.
This landmark study highlights the urgent need for conservation efforts to address the global decline in genetic diversity. By implementing tailored strategies and preserving the genetic variability of species, it is possible to mitigate the impacts of ecological disturbances and ensure the resilience of populations in the face of environmental changes.
ALSO READ: ‘Blood Falls’ Mystery: Scientists Unveil the Secret Behind Antarctica’s Red Waterfall