In the midst of an extinction crisis that demands immediate action, recent Imperial College London research reveals a simple yet significant solution: protecting less than 1% of our planet may reduce threats to a third of endangered and evolutionary distinct species.

Researchers make this claim after discovering Evolutionarily Distinct and Globally Endangered (EDGE) zones, home to diverse and densely populated species, such as the aye-aye, tetrapod, and critically endangered gharial, holding the last refuges of millions of years of evolutionary history.

The study examined the distribution of almost 3,000 EDGE species, finding 25 EDGE zones with the highest conservation potential. Maximum richness was found in an area of less than 100 square kilometres in Madagascar, which, along with Mexico and Indonesia, contained the highest number of EDGE species. Large parts of Southeast Asia and the Indo-Gangetic plain, the Amazon basin and the Atlantic Forest, as well as in Hispaniola, the highlands of Cameroon, and the Eastern Arc mountains of East Africa, are also underlined.

However, the extinction crisis is a global emergency, threatening not just one species branch but the entire evolutionary tree. With only 20% of the critical zones protected, researchers are urging action now to prevent irreversible loss.

Symbiotic Futures interviews Sebastian Pipins, PhD, discussing the importance of his research:

How do EDGE Zones highlight the importance of preserving unique evolutionary histories, and why is this critical for maintaining the diversity of life on Earth?

EDGE zones show that there is a real opportunity for conservation. Biodiversity has been squeezed into tighter and tighter confines, and the world is now in a state where huge swathes of species exist within a relatively small portion of the world’s land surface. Our study speaks to this point, where we found that one third of the world’s most evolutionarily distinct and globally endangered species are found within just 0.7% of the world’s land surface, with half being found nowhere else. These EDGE zones show how very large conservation gains can be made from relatively small accessions to the global protected area network. They are not the only places that need to be protected, and much larger areas also need to be conserved to ensure the abundance of species across their ranges. However, the failure to protect these EDGE zones would have huge consequences for the tree of life and could result in many unique species and lineages being permanently lost.

What role do species with high evolutionary distinctiveness play in their ecosystems, and how does their loss impact ecological balance?

Some species are the result of long periods of unique evolutionary history and have thus come to represent highly distinctive forms. The aye-aye and the purple frog are great examples of this. Both are distantly related to other living species and have come to represent remarkably unique behaviours and morphologies, what with the aye-aye’s highly specialised and elongated third and fourth finger and the purple frog’s strange pig-nosed and turtle-bodied appearance and its habit that sees it spend most of its life underground. 

It’s hard to quantify the exact role a species has in an ecosystem, especially for those that are rare and threatened, like the aye-aye and the purple frog, but there is an argument that those that are more unique might be more irreplaceable. We also know from studies on plants and birds that more evolutionarily distinctive species provide more unique services that humanity depends on. So when it comes to conservation deciding what to spend its limited resources on protecting, it’s hard to overlook the importance of these weird and wonderful species.

The study found that 75.6% of EDGE species exist within a single country. How can local conservation efforts be better supported by global cooperation to address this uneven distribution?

I think this is a crucial finding because it shows just how important it is for nations to show leadership. If some can be bold with their conservation goals, then it opens the way for others to follow suit. However, most tetrapod diversity exists in the tropics, in low-income countries that face serious challenges when it comes to preserving biodiversity. When there are economic pressures for education and health, combined with potential political instability, then it’s hard to get conservation goals on the agenda. I think this is where global cooperation comes in. Those countries with the lion’s share, who have profited off the environmental degradation in the tropics, should hold themselves responsible and funnel resources into these regions. Ultimately, individual nations must be the ones to protect their diversity, and they must do it because they feel it is important, not because other nations tell them to. That being said, global conservation organisations and high-income countries can do a lot to both financially facilitate this process and to spread awareness on the importance of preserving nature.

Given that EDGE Zones face human pressure, how can conservation strategies be designed to benefit local communities and biodiversity?

Conservation can and should be of benefit to nature and local communities. It all stems from designing strategies that put these communities at the heart of the decision-making process. Projects with local buy-in from the start are usually the ones that can run the furthest. Given the deprivation seen in EDGE zone regions, alternative livelihoods that can benefit both nature and individuals can be promoted. For instance, sustainable farming, or eco-tourism can enable conservation efforts and provide economic relief for communities. Meanwhile, global conservation organisations and nations can help fund and empower local organisations to take the lead on these projects. 

With only 20% of identified EDGE Zones currently under protection, how urgent is it for world leaders to integrate EDGE-focused conservation into biodiversity goals like the 30 by 30 target aiming to protect 30% of Earth by 2030?

When working towards big targets like 30 by 30, it’s essential that the right places are chosen to be protected. The last thing we need is to spend precious resources on protecting areas that offer very little benefit for biodiversity. Unfortunately, the opportunistic nature of protected areas means this can often be the case. Meanwhile, EDGE zones clearly highlight areas of irrefutable importance. If we are to adequately preserve the world’s most unique species and lineages, then these are areas that cannot be ignored, and world leaders will have to take notice of this. 

All this being said, there is no one-silver bullet strategy for nature. Biodiversity is so complex and the crisis is so multifaceted that the conservation community has agreed on 23 targets to help get nature back on track by 2030. EDGE is a component of this, but it’s key that we don’t oversimplify the challenge that conservation faces. The EDGE zones shed light on the areas of utmost concern for conserving the evolutionary history of tetrapod animals, but we are also working on expanding this approach to plants and fish, and hopefully one day to fungi and invertebrates too. In defining these priorities and encompassing as many taxonomic groups as we can, we are trying to make it as easy as possible for world leaders to take this information into account and help safeguard the tree of life. 

Interview by Venya Patel