Snakes have long been regarded as fascinating creatures, with their slithering bodies and venomous fangs. But what sets them apart from other reptiles? According to a recent study published in the journal Science, scientists have discovered that snakes possess a supercharged evolutionary clock that allows them to adapt at an astonishingly fast rate. This unique ability has made them “winners” in the animal kingdom and has enabled them to spread across the planet.
Lead author Pascal Title, an evolutionary macroecologist at Stony Brook University in New York, compares snakes to the Big Bang singularity in cosmology. He describes them as a dramatic expansion of diversity in species and ecologies, linked to some event that may have occurred early in their evolutionary history.
To understand why certain animal groups are more successful at diversifying into more species and surviving mass extinctions, the researchers focused on squamates, the order of reptiles that includes snakes and lizards. Among these reptiles, snakes stand out for their incredible diversity. With approximately 4,000 known snake species ranging from venomous sea snakes to tiny burrowing threadsnakes, they have adapted to various habitats and dietary preferences.
The scientists conducted an extensive study of the genomes of nearly 1,000 snakes and lizards to unravel the secrets behind snakes’ evolutionary success. They also examined the stomach contents of over 60,000 museum specimens and made field observations to understand their dietary preferences. By combining this data, they constructed a comprehensive evolutionary tree that traced the bodily and dietary changes in snakes and lizards over time. Mathematical and statistical models were then used to analyze the evolution of these reptiles.
The findings of the study revealed that snakes underwent multiple evolutionary explosions and evolved three times faster than lizards in terms of diversity. The first burst of diversity occurred between 128 million and 70 million years ago during the Cretaceous period. Another significant pulse followed the extinction of dinosaurs at the end of the Cretaceous. Remarkably, this rapid rate of evolution continues to this day.
Daniel Rabosky, an evolutionary biologist at the University of Michigan and one of the study authors, explains that snakes have been changing relatively quickly compared to lizards. He describes their “evolutionary explosion” as an ongoing process driven by their fast-ticking evolutionary clock. This clock allows snakes to evolve new traits rapidly, enabling them to take advantage of opportunities that arise in their environment.
One of the key factors contributing to snakes’ success is their evolutionary flexibility. They can change their body shape and dietary preferences swiftly. The initial singularity that led to their success involved the development of limbless bodies, flexible skulls, and advanced chemical-detection systems. These adaptations allowed them to target a wide range of prey, providing a foundation for individual species to specialize and thrive.
Interestingly, research published in 2021 suggests that the diversity in snakes’ diets exploded after the extinction of dinosaurs. Snakes quickly adapted and evolved new traits to exploit the new world they found themselves in—a world without dinosaurs but with emerging mammals.
Despite these fascinating discoveries, scientists are still puzzled as to why snakes possess such a fast evolutionary clock in the first place. Rabosky admits that this remains a mystery that requires further investigation. However, he emphasizes that solving one mystery often leads to new questions in the field of science.
Looking ahead, it seems that snakes are continuing to adapt and evolve at a rapid pace. Rabosky speculates that there are no signs of their evolutionary clock slowing down. Snakes are constantly finding new ways of life, and it is expected that this trend will persist into the future.
In conclusion, snakes’ supercharged evolutionary clock has made them true winners in the animal kingdom. Their ability to adapt quickly has allowed them to diversify into numerous species and spread across the planet. From their limbless bodies to their advanced chemical-detection systems, snakes have evolved unique traits that have propelled their success. While the reasons behind their fast evolutionary clock remain a mystery, scientists are confident that snakes will continue to evolve and adapt in the future.
