Evolution: how snakes change size and shape depending on their habitat

There evolution of the animals can be analysed, among other aspects, through natural environment in which they lived and live. In this sense, recently, a group of experts studied how the snakes Since Chaco Ecoregion -between Argentina, Bolivia, Paraguay and Brazil– are located in the forests at your best adaptation Al environment. Thus, the results showed that the size and the physiognomy of these species can vary depending on where they are.

He scientific studieswho was in charge of specialists from Paraguay and Brazil and was published in the magazine Ecology and Evolution, showed that most of the specimens which are found in the lower part north of the analyzed region tend to have long tails, which can be almost half of its total length. It means they are arboreal or semi-arboreal animalscon prehensile tails They can grab branches or other objects.

The most favorable area for these snakes is closer to the Amazon, the Andean jungle and Chiquitania -east of Bolivia-. It is a humid sector with a great diversity of trees.

On the other hand, in the part on of this ecoregion, the species have shorter tails there small eyeswhich means they can live underground. “It’s an adaptation that allows them to survive the high temperatures of this part of the Chaco, which can reach 48°C. The ground here is sandy, so snakes can dig burrows easily,” the researchers note.

Thaís Guedes, one of the authors of this work, explained: “One of the questions we had in mind was whether snake species were evenly distributed in the Chaco. Analysis showed no. Its distribution is closely related to habitat, and entire evolutionary groups often occur in the same area, reflecting the selective pressure exerted by the environment.”

For his part, Hugo Cabral, another of the scientists in charge of the study, described: “The differences are evident in the morphology. In the drier south, most species are burrowing – living mainly underground – while in the north, which is influenced by the Amazon and other rainforests, the snakes are mainly arboreal – arboreal –”.

To reach these conclusions, the experts carried out a computer analysis of a database containing ecological and morphological information on 140 species of snakes that inhabit the Chaco. The ecological part included information on the habitat (aquatic, terrestrial, arboreal, semi-arboreal, burrowing or semi-fossorial); while the morphological part concerned the length of the muzzle and tail; the total length; body mass and eye diameter.

These data were overlaid on a map of species distribution in the Chaco and cross-referenced with environmental variables such as climate, vegetation and soil sand.

“The Chaco is neglected in biodiversity studies. Additionally, in recent decades, the region has experienced high rates of deforestation. Understanding ecological and evolutionary processes is therefore increasingly relevant,” Cabral said. And he added: “The few existing studies analyze the northern and southern parts of the Chaco separately. This is the first time that he has been fully investigated. Species don’t care about borders. A broader and more integrated approach is needed.

For Guedes, “research like this provides important guidance for more effective conservation strategies. For example, when planning the creation of one or more protected areas”. Because? “Because it is now possible to define places that contain not only the greatest number of species, especially if they are endemic, but also the greatest diversity of evolutionary histories”, specifies the scientist.

Diego Santana, who worked with Cabral and Guedes on this study, concluded: “We know that we probably won’t be able to protect the whole biome, but we have enough information to help define the areas with the greatest potential to protect as many groups of species as possible. Tropical forests occupy a very large part of South America and, partly for this reason, relatively little is known about the continent’s other ecosystems, such as the Chaco, which has great biodiversity.

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