Over the past 200 years, researchers have worked to understand the global distribution of species and ecosystems. But so far, even basic knowledge of the global geography of genetic diversity has been limited.
That is now changing with the recent work of the Globe Institute. Professor David Nogues Bravo and his team have spent the past eight years combining data from scientific gene banks with scenarios of future climate change and land use. The result is the first global assessment of how it will affect mammalian genetic diversity, e.g. When tropical forests turn into agricultural land.
‘Our study identifies both genetically poor and very diverse areas that are severely exposed to global change, paving the way for a better assessment of vulnerability to global changes such as rising temperatures as well as land use changes. It could help countries discover how much of the genetic diversity in their country can be exposed to different impacts of global change, while establishing conservation priorities and policies, ‘says David Nogues Bravo.
For example, northern Scandinavia will be strongly affected by climate change, not so much by land use change, while tropical areas of the world will suffer from both climate change and land use change. However, David Nogues Bravo emphasizes that it is difficult to compare areas.
‘Genetic diversity in Scandinavia will always be less than in the tropics, but that doesn’t mean that overall diversity there doesn’t matter. If we lose populations and species like the polar bear, it’s just one species, but it will, it will affect the overall stability of the ecosystem. However, the greatest threat to genetic diversity will be in the tropics, which currently contain the greatest diversity of bricks of life, genes. These regions include ecosystems like mangroves, jungles and grasslands, ‘says David Nogues Bravo.
All that together
The researchers investigated gene banks with mammalian mitochondrial data. Mitochondria also regulate metabolism, and by looking at how it has changed over time, it can also detect changes in diversity.
‘Mitochondrial diversity is a broad assessment of adaptive capacity. We also thought that mitochondria are a neutral marker, when in fact they are in the selection phase. This means that some of the choices may relate to the physiological boundaries of the species in relation to the climate, making it a very useful tool for researchers to monitor how global changes affect genetic diversity in a given area, ‘explains David Nogues Bravo.
Geographical data were not available for many samples. The researchers used artificial intelligence to add geographic locations, and then built models that predict how much genetic output there is in places without data.
The researchers then analyzed maps of genetic diversity, future climate change, and future land use change, to discover how and where global change will affect mammals.
Interest agency of the United Nations
The research attracted the attention of the Secretariat of the United Nations Convention on Biological Diversity. David Nogues Bravo hopes that the assessment map could become an important tool for high-level summits among countries to help define biodiversity protection policies.
‘It is only now that we are beginning to have the tools, data and knowledge to understand how genetic diversity is changing around the world. In the ten years from now, we will also be able to know how much of that genetic diversity has been lost by the industrial revolution to thousands of species and in a stronger position to adopt effective protection measures, ‘he says.
In the coming years, he hopes that scientists will map the global genetic diversity of many other life forms, including plants, fungi and animals across countries, rivers and oceans.
‘Attempts have been made to map the genetic diversity of amphibians, birds and reptiles, but we do not have maps for plants, insects or fungi. And while there are about 5,000 species of mammals, there are many more species of insects or fungi, perhaps millions. We don’t even know how much yet. It will take more time, but it will come in the next decade, ‘he says.
“We hope to see more of these estimates in the next decade, and then supplement them with long-term monitoring programs, in which we can continuously monitor the genetic diversity of thousands of species and ecosystems around the planet,” says David Nogues Bravo.