An ecological crisis overshadowed by the threats of mass species extinctions and climate change impacts could be just as serious to ecosystems and human society, according to a new study by an international team of scientists. However, there are actions that could help combat this hidden, understudied issue.
Genetic diversity, which reflects the variation in DNA within species and populations and is the key to their capacity to adapt in times of change, is being lost at an alarming rate.
According to the article by 28 authors, including Dr Anna MacDonald from The Australian National University, the loss of genetic diversity can affect resiliency in the face of environmental change. Once gone, genetic diversity can take millennia to return.
"We know that genetic diversity is eroding, that it is happening fast, and that as a consequence nature is losing its resilience at a time when we need it most," lead author Dr Sean Hoban from The Morton Arboretum, USA, said.
"Genetic diversity isn't visible to the eye, and in many cases it decreases before impacts are evident in a species' population."
As shown in the new paper, scientists can now document changes in genetic diversity and devise actions to help. The use of museum specimens and genetic datasets collected over decades are showing that genetic diversity erodes long before species disappear.
The authors also use findings from the Living Planet Index, which shows that species populations have declined by 68%, to forecast dramatic losses of genetic diversity (more than 50% loss for many species), if no protective actions are taken. Ongoing losses are already making natural and human systems, from coral reefs to farms to urban trees, highly vulnerable to extreme events like heat waves.
Monitoring genetic diversity (directly analysing DNA within species over time) can help to detect vulnerabilities. The authors point out that monitoring genetic diversity is rapidly becoming more affordable due to major technological developments in genomic sequencing in the past 20 years. But, the article explains, technology must be made available globally, expert guidance is needed on its most efficient use, data must be made open and accessible, and knowledge must be synthesized for use by political leaders.
"In the face of growing pressures on biodiversity, it is increasingly important to make genetic information more accessible to conservation managers and policy-makers around the world, and form partnerships to put that information to use in practice," Dr MacDonald said.
"Now is the time to build from recent advances in DNA sequencing technology and genetic knowledge, to standardise the way we collect genetic data for management, and develop guidance on how best to use genetic information in biodiversity conservation."
The study has been published in BioScience.