Mountains, Lizards, and a Race Against Time

Iran’s Endemic Reptiles Face the Heat

_{Edited by Rick van Mechelen, from Final Report: Conservation of Darevskia Lizards in Iran}

Deep within the forested valleys and rugged slopes of northern Iran lives a group of little-known lizards facing an uncertain future. A recent research project has shed new light on these rare reptiles, combining DNA analysis and climate modeling to assess the long-term survival prospects of six species of lizards that are found nowhere else on Earth.

The study, led by Dr. Saeed Hosseinian Yousefkhani and funded by the Herpetofauna Foundation, focuses on six species from the Darevskia genus: D. defilippii, D. caspica, D. schaekeli, D. steineri, D. kamii, and D. kopetdaghica. All of these lizards are unique to Iran’s mountainous north. The findings are striking: some species are genetically fragile, others are isolated in shrinking habitats, and almost all face serious threats from climate change within the next 50 years.

Hidden Treasures in Iran’s Mountains

The Darevskia lizards may be small, but they are an important part of their ecosystems, helping to control insect populations and serving as food for birds and mammals. They also act as indicators of environmental health, as their well-being reflects the condition of their surroundings. But most people have never heard of them.

These lizards are primarily found in the Alborz and Kope Dagh mountain ranges that stretch across northern Iran. The region is a hotspot for biodiversity, where high peaks and deep valleys create isolated habitats, resulting in perfect conditions for unique species to evolve over time. The Alborz Mountains in particular form a biological bridge between the Caucasus in the west and Central Asia in the east, allowing species to move and mingle, but also to become stranded in remote valleys when the climate changes.

For the Darevskia lizards, this natural isolation is both a blessing and a curse. On one hand, it has led to the development of genetically distinct species. On the other, it makes them extremely vulnerable to even the smallest environmental fluctuations.

Rewriting the Lizard Family Tree

The first step in the research involved mapping out how these lizards are related to one another. Using two pieces of genetic material from each species (small sections of DNA known as the Cytb and MC1R genes) scientists were able to compare the genetic differences among them.

This approach, called phylogenetic analysis, works like building a family tree. It shows which species are closely related and which ones branched off long ago. Some of the results confirmed earlier findings: for instance, the Darevskia species in Iran fall into two main groups: Persiodarevskia and Hyrcanodarevskia. But the study also uncovered surprising levels of diversity within individual species.

For example, Darevskia schaekeli, found in a few remote valleys of the eastern Alborz Mountains, showed significant genetic differences among its populations. These differences suggest that these populations have been isolated for thousands of years. The genetic difference between some populations of this single species was over 4%, which is unusually high and hints at the possibility of hidden, unrecognized species.

Similarly, D. steineri was found to have two main population groups on either side of Golestan Province. Though the genetic difference between them is smaller, it’s enough to show that they’ve been living separately for a long time. These differences matter because isolated populations are often more vulnerable to extinction.

Looking Ahead with Climate Models

While DNA offers a snapshot of the past, climate modeling gives a glimpse into the future. Using a method called Maximum Entropy modeling, the research team predicted where each species could potentially live in the year 2070, based on a range of climate change scenarios.

The results show that all six species are expected to lose significant parts of their current habitats. In the case of Darevskia caspica, which now lives in areas east and south of the Caspian Sea, its range is projected to shrink toward the coastline. D. defilippii is likely to disappear from many of its current habitats in the central Alborz Mountains. The already limited range of D. kami, now found in the forests of Golestan and southeastern Mazandaran, will shrink even further.

Even the hardier species aren’t safe. D. kopetdaghica, for instance, currently lives in a small part of northeastern Iran near the Turkmenistan border. While some models suggest that similar mountain areas elsewhere in Iran might look suitable, there is no way the species will spread there, making it vulnerable to climate change and habitat loss.

In general, all tests show the same results: the species that already have the smallest ranges will suffer the most. Those limited to cooler, wetter highlands will be pushed even further uphill as temperatures rise, eventually running out of space.

 A Call for Conservation

While some of the species’ current habitats are within protected areas, protection alone is not enough. Without targeted conservation plans such as preserving climate refuges, managing forests, and perhaps even relocating individuals between isolated populations, many of these species could decline or disappear entirely.

One major takeaway from the study is the importance of genetic diversity. Populations with high genetic variation are more likely to adapt to changing conditions. That’s why D. schaekeli and D. steineri, despite being rare, are particularly valuable. These species hold genetic "insurance" for their species. Losing them would mean losing thousands of years of evolutionary history.

The study also demonstrates the power of combining genetics with climate science. By looking at both a species’ habitat and its genetics, researchers can make more accurate predictions and better conservation decisions.

Iran’s Natural Heritage at Risk

This research is more than just a report on some little-known lizards. It’s a broader warning about the pressures facing Iran’s mountain ecosystems and the urgent need to act before unique species are lost forever.

Iran’s mountains are not just beautiful, they’re cradles of life. But their future, and the future of the species they shelter, depends on the decisions we make now.

Learn more about this project