The Role of Genetic Diversity in Addressing Biodiversity Loss
Tue, April 20, 2021

The Role of Genetic Diversity in Addressing Biodiversity Loss

 

Wildlife has been the most vulnerable to the impacts of climate change. Animals are struggling to survive while also trying to get away from the destructive nature of humans. The 2018 Living Planet Index by the World Wildlife Fund reported that the populations of wild animals have decreased by more than half - 60% - in less than five decades. Vertebrate population sizes plummeted by 60% from 1970 to  2014, while freshwater populations sank by 83%. 

Marco Lambertini, the director-general of WWF International, said that this “is a grim reminder and perhaps the ultimate indicator of the pressure we exert on the planet.” “There cannot be a healthy, happy and prosperous future for people on a planet with a destabilized climate, depleted oceans and rivers, degraded land and empty forests,” he said. 

According to the World Economic Forum, an independent international organization committed to improving the state of the world by engaging business, political, academic, and other leaders of society to shape global, regional, and industry agendas, human activity is taking a heavy toll as evidence by the reports on habitat loss, pollution, climate change, over-exploitation and the spread of invasive species and diseases. The report showed that species’ population declines were the most dramatic in South and Central America, experiencing a decrease of 89%. 

“It’s clear that efforts to stem the loss of biodiversity have not worked and business, as usual, will amount to, at best, a continued, managed decline. That’s why we, along with conservation and science colleagues around the world, are calling for the most ambitious international agreement yet – a new global deal for nature and people – to bend the curve of biodiversity loss,” the report said. 

 

 

Can Genetic Diversity Help?

Scientists have long studied how we can help wildlife, especially the most vulnerable species, thrive. One of their solutions is genetic diversity, the variation in the genetic composition among individuals of a population, a species, an assemblage, or a community. This is a way for any population to adapt to changing environments. With more variation, it is more likely that some individuals in a population will possess variations of alleles that are suited for the environment. Conservationists have also proposed revitalizing these species by bringing in new blood from larger populations. 

A 2018 study conducted by a team of researchers from the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) revealed that genetic diversity makes animal populations more resistant to disease. They explained that the ability of species to respond more effectively to changes in the environment, such as the occurrence of disease, although they have different genetic variants is their way of surviving. While many zoos across the world have worked to maintain genetic diversity in endangered species by carefully matching individual animals for breeding, it is not usually tried in nature. 

Brendan Reid, a conservation biologist at Michigan State University, said that adding new blood to small populations can help animals. Together with his team, Reid engaged in a long-term experimental evolution study of wild guppies in Trinidad. According to Science Mag, the peer-reviewed academic journal of the American Association for the Advancement of Science, they seeded the headwaters of two streams in the mountainous country with guppies taken from a distant habitat. The findings of the study showed that the populations increased 10-fold and genetic diversity doubled.

Unfortunately, humans, again, are disrupting genetic diversity. A study published in the journal Ecology Letters revealed that environmental changes caused by humans are leading to changes in genetic variation in thousands of species of birds, fish, insects, and mammals. As a result, many species we rely on may disappear as their susceptibility to habitat loss, pollution and climate change grows. Co-author Andy Gonzalez stated that the loss of genetic diversity will affect the ability of animal populations to adapt to changing environments. 

"This is currently our best estimate of how humans are impacting animal genetic diversity worldwide. We found that there is an effect of humans on animal genetic diversity, but it is a matter of species and spatial scale because we found nearly equal instances of increasing versus decreasing trends,” lead author Katie Millette, a Ph.D. candidate in the Biology Department at McGill, said. 

According to Technology Networks, an internationally recognized publisher that provides access to the latest scientific news, products, research, videos and posters, the researchers used the largest genetic data repositories available, which contains over 175,000 sequences from more than 27,000 populations of 17,082 animal species. They were able to assess whether the effect of humans has resulted in temporal trends between 1980 and 2016 using the year each genetic sequence was collected and its spatial coordinates. “We need to monitor the genetic diversity of wildlife so that we can understand better where, when and why it is declining in some places and increasing in others,” the researchers said. 

 

 

Scientists Encourage Genetic Diversity

Earlier this year, the Convention on Biological Diversity (CBD) released a provisional action plan, a strategic planning framework used to help plan, implement and evaluate the impacts of the actions taken to help our environment. It will be the basis of a 10-year plan to protect nature. In the framework, the CBD describes the urgent need to halt biodiversity loss by 2030 and to live in harmony with biodiversity by 2050.

The plan, which was designed to guide countries' actions in conserving biodiversity and assessing their progress, sets out five objectives to protect our nature. This includes advancing sustainable development; protecting ecosystems, species and genes, and ensuring equitable sharing of benefits arising from the use of biodiversity and traditional knowledge. However, many scientists stated that these targets are not broad enough.

Recently, a letter published in the journal Science showed that scientists call for an urgent rethink on a draft action plan to safeguard biodiversity. According to Phys.org, an internet news portal that provides the latest news on science, the experts believe that the plan neglects genetic diversity despite a wealth of scientific evidence to back up the crucial role it plays within species for ecosystem resilience, species survival, and adaptation.

"This letter is a timely warning that at a time when the world's conservation community is taking critical steps to halt the further loss of global biodiversity, genetic variation must be maintained and enhanced where possible," Professor Bruford, co-chair of the International Union for Conservation of Nature's Conservation Genetics Specialist Group, said.