Uncovering Hidden Biodiversity in one of the World’s Harshest Frontiers
In Chile’s Atacama Desert, famed as the driest place on Earth, a tiny group of geckos is rewriting what scientists thought they knew about species diversity. A cutting-edge genomic study led by researchers including Kamryn Carter from the University of Wollongong (UOW) reveals that the local gecko lineage, known as Garthia geckos or Chilean marked geckos, is far more diverse than previously believed. Far from a single species, the Atacama’s geckos may comprise up to 11 distinct species, a finding that redefines how life adapts to extreme aridity and heat.
From Shape to Genome: Why Appearance Isn’t Decisive
For years, scientists relied on morphology—the visible shape and coloration of organisms—to differentiate species. In the case of Garthia geckos, a prior assessment suggested there were two species based on subtle color patterns. Kamryn Carter, a PhD candidate in UOW’s Environmental Futures Research Group, explains that these lizards appeared almost identical to the naked eye. “Historically, Garthia geckos were considered two species based on morphology, but a recent study on their colouration patterns suggested there was only one species,” she notes. This discrepancy between appearance and genetics prompted a deeper dive into their DNA.
Genomics Unveil Deep Genetic Divides
The team applied modern genomic methods to compare both mitochondrial and nuclear DNA across gecko populations spread throughout the Atacama. Collaborators in Chile and the United States joined UOW researchers to map evolutionary history and genetic differences with unprecedented resolution. The results were striking: two visually indistinguishable species, Garthia penaii and Garthia gaudichaudii, diverged roughly 20 million years ago, underscoring how long evolutionary lineages can remain cryptic in the field.
Hidden Diversity: Up to 11 Cryptic Species
Beyond the two clearly distinguishable lineages, the analysis suggests there may be as many as 11 distinct species within what scientists once treated as a single group. This hidden diversity means the Atacama’s gecko fauna is richer—and more fragile—than previously assumed. “Traditional approaches often overlook cryptic species, underestimating biodiversity and limiting our ability to conserve these unique lifeforms,” says Dr Damien Esquerré, a co-author of the paper.
Implications for Conservation in a Warming World
Cryptic species are more than a taxonomic curiosity; they represent unique evolutionary journeys and specific ecological needs. The Atacama, already pushed by climate change and habitat loss, may see shifts in how these geckos survive in extreme aridity, temperature swings, and scarce resources. By recognizing distinct genetic lineages, conservation planners can tailor strategies to protect each cryptic species, preserving the evolutionary potential of this remarkable desert biome.
What This Means for Evolutionary Biology
Beyond the Atacama, the study demonstrates the power of genomics to illuminate how life adapts under stress. The discovery of deep genetic splits among morphologically similar individuals highlights a central lesson in evolutionary biology: appearance can be deceiving, and DNA can reveal histories millions of years in the making. The Atacama’s Garthia geckos therefore offer a natural laboratory for studying speciation, adaptation, and resilience in one of the planet’s most challenging ecosystems.
The Research at a Glance
The study, titled “Hidden diversity in the driest desert on Earth: genomics unveils cryptic diversity in an ancient South American gecko lineage (Phyllodactylidae, Garthia),” was led by Kamryn Carter with contributions from Claudio Reyes-Olivares, Jonathan Eubanks, Hayden Hanna, Stuart Nielsen, and Damien Esquerré. It appears in Molecular Phylogenetics and Evolution, signaling a new era of biodiversity discovery in South America’s deserts.
Why This Matters to You
Whether you are a conservation advocate, a science enthusiast, or simply curious about the natural world, the Atacama’s hidden gecko diversity reminds us that Earth still holds surprising genetic stories. As climate pressures mount, recognizing cryptic species becomes essential to safeguarding life’s remarkable adaptability for future generations.
