Key points
- Genetic diversity is biodiversity that exists within species, enabling them to adapt to the changing world around us.
- Indicators of genetic diversity provide a way to measure and monitor levels of genetic diversity over time and check the genetic health of species and ecosystems.
- Genetic diversity can be monitored on a global scale to save animals, plants and other biodiversity from extinction.
Ask a 10-year-old to name some extinct animals and they can usually rattle off ancient species such as the Tasmanian Tiger, Woolly Mammoth and Dodo. Some may even be able to tell you what the animals used to look like without searching online.
What’s not simple is preventing species decline and further extinction for years to come. This is especially true in the face of human activities that have accelerated the extinction rate of animals, plants and even fungi. In fact, it’s taking a global effort to tackle this challenge, including some pretty clever biodiversity experts. They believe a key element to protecting species is being able to measure and maintain genetic diversity.
A global mandate
In December 2022, the United Nations’ Convention of Biological Diversity adopted the Kunming-Montreal Global Biodiversity Framework (GBF). It provides a path to live in harmony with nature, with significant progress by 2030. About 196 countries have committed to report the status of genetic diversity for all species. The aim is to conserve genetic diversity of all species, not just economically valuable or domesticated species such as crops or cattle.
The GBF outlines goals for conserving precious biodiversity on a global scale. To meet these, countries from around the world need to be involved and reporting needs to be consistent to be able to understand how well biodiversity is being conserved at national and international levels.
What are genetic diversity indicators?
Our conservation geneticist Dr Rebecca Jordan and Associate Professor Catherine Grueber from the University of Sydney co-led the Australian part of a global study, working with partners across Australia. A truly international collaboration, the paper included teams of scientists from Mexico, South Africa, Japan, France, USA, Sweden, Colombia and Belgium. The paper, published in Ecology Letters this month demonstrated that it was feasible to calculate genetic diversity indicators for United Nations 'or global' reporting. The paper also provided an example methodology to do this.
Genetic diversity is the level of biodiversity that exists within species, enabling them to adapt to the changing world around us. Rebecca believes ensuring the conservation of genetic diversity is critical for supporting the long-term survival of our species in the face of climate and environmental change.
“Genetic diversity indicators, like other biodiversity indicators, provide a means of measuring and monitoring genetic diversity over time to assess and track the genetic health of species and ecosystems,” she said.
Choosing the right indicators
The scientists involved in the study used two indicators that captured information on genetic diversity within and between populations of each species. These were:
1. Populations large enough to retain genetic diversity
2. Maintaining genetically distinct populations
This information is fundamental to understanding the genetic health of species.
“Recording genetic diversity indicators lets us measure the effects of population size and habitat disruption on each species, and plan management strategies to prevent extinction,” Catherine said.
An international perspective on genetic diversity
The study assessed the two genetic indicators for more than 900 species, representing 5271 populations across nine countries, including megadiverse countries and developing economies. It spanned taxonomic groups including reptiles, birds, mammals, fish, invertebrates, plants and fungi. Collaborating internationally enabled the team to test methodologies across many species in many ecosystems and many countries, providing information on how feasible these indicators would be internationally.
The majority of species assessed in the study have retained most of their populations. However, 58 per cent of them have populations that are too small to sustain genetic diversity.
“Where populations of species aren’t large enough, genetic diversity may decrease over time,” Rebecca said.
“This increases the risk that those populations won’t be able to adapt and may be lost in the future.”
While 58 per cent of populations may be at risk, researchers believe there is still plenty that can be done to help those species.
Measuring and monitoring genetic diversity
Being able to effectively measure and monitoring genetic diversity over time means that genetic health can be tracked, and, with the right actions, losses prevented. In Australia, genetic data is helping inform current and future management of the numbat.
Sweden recently initiated a national genetic monitoring program with species such as cod, salmon and moose, which are heavily harvested, to help prevent their collapse.
“The global perspective in this paper shows us what we can learn from others, and also how to protect the unique species that are found in special places around the world,” Catherine said.
“Australia is incredibly rich in biodiversity. Many species found here are unlike anywhere else in the world. We have seen the significant threats to our country’s species, such as the devastating 2019 to 2020 bushfires. Protecting the resilience of Australian species, by preserving their genetic diversity, will help our environment thrive for generations.”
Rebecca reminds us that conserving biodiversity is an international challenge.
“While we live in different countries, our species and ecosystems do not consider these artificial boundaries. Our planet’s health, that we are so reliant on, is dependent on the health of species across the globe. We need to support all species to survive and thrive in a changing world.”