Show us your feet … and watch the marvelous evolution
The marbled bent-toed gecko Cyrtodactylus marmoratus is native to Java and Sumatra and belongs to the group of generalists. © Adobe Stock
Animals always appear perfectly adapted to their respective habitats. Geckos are known for their specially equipped feet, which enable them to cling to even the smoothest surfaces. Numerous biomimetics inventions are based on this principle. LIB researchers have looked at another aspect of this species-rich and widespread group of lizards.
Adaptive radiations – when closely related species adapt to different environments in a variety of ways – are fascinating for evolutionary biologists. The body and leg proportions of geckos, which occur in a wide variety of habitats, often change. Researchers suspect that geckos that live in more open landscapes have longer hind legs to be able to run faster. In contrast, geckos that climb trees or rocks may have shorter legs to keep their center of gravity closer to the substrate to save energy and be more agile. Zoological collections such as the LIB’s allow us to study such questions and thus better understand evolution in general and predict how and how quickly organisms adapt to changing environmental conditions. Unfortunately, according to the scientists, climate change and other man-made habitat destruction also play a role here, as animals and plants have to move to new habitats for which they are not evolutionarily adapted.
LIB researchers have taken a closer look at a specific group – the bow-fingered geckos of the genus Cyrtodactylus. These geckos live mainly in Asia in different environments and have different preferences for certain structures. For example, there are some that prefer to live on granite and others that prefer to live in highly rugged karst areas or on trees.
The international research team led by LIB PostDoc Dr. Jendrian Riedel and LIB herpetologist Priv.-Doz. Dr. Dennis Rödder measured and examined the body length and leg size of 87 species to find out whether there is a connection between their locomotion and the environment they live in. The result was that groups of geckos living in different environments differ in their body shape. Although there are overlaps, especially in similar microhabitats such as granite and karst areas, overall the findings support the research group’s assumptions about adaptations to environmental conditions. Only the group of bush- and canopy-dwelling bow-fingered geckos did not show any unique trait combination.
“The implications of our results are extremely exciting,” says first author Jendrian Riedel, “because it could mean that some of the species evolved without a complete spatial separation of the original population.” This phenomenon, known as sympatric speciation, has so far only been documented in a few species, such as certain cichlid species from crater lakes, and according to conventional wisdom is rather an exception. Geckos therefore remain extremely fascinating – especially their feet.
To the paper: https://link.springer.com/article/10.1007/s11692-023-09622-3#citeas
