Evolutionary Family Tree of Snakes and Lizards Details 4,100 Species

A team of researchers have reportedly created the first ever large-scale evolutionary family tree for every snake and lizard in the world.

Since 2008 researchers have been gathering data, cataloging details of 4,161 species of lizards and snakes, collectively known as squamates.

"Squamates include all lizards and snakes found throughout the globe, including around 9,500 species on every continent except Antarctica, and found in most oceans," said Dr. Alex Pyron, an assistant professor of biology at George Washington University who was involved in the research. "This is everything from cobras to garter snakes to tiny geckos to the Komodo Dragon to the Gila Monster. They range from tiny threadsnakes that can curl up on a dime to 10 feet monitor lizards and 30 foot pythons. They eat everything from ants to wildebeest."

While some branches of the evolutionary family tree have gaps, Pyron said it mostly includes all families and subfamilies and most genus and species groups.

"It's like building an incomplete family tree for your family, but with half of the 'children' sampled. You're in it, but not your brother, one of your cousins is, but not another. However, because it's so complete, we know where the missing relatives go because there's no longer as much mystery as to how the missing species, or cousins, are related, with a few notable exceptions for some remaining species.

"This is also a community effort. We sequenced hundreds of these species ourselves but took thousands more from public databases, building on the work of others."

Pyron said the evolutionary family tree, or phylogeny, will help further understanding of how various snakes and lizards are connected to each other, especially because before this, there were no single reference for how all lizards and snakes were related or what their classification was.

"A phylogeny and taxonomy is fundamental for all fields of biology that use lizards and snakes, to understand how to classify the species being studied, to interpret biological patterns in terms of relatedness, and even at a more basic level, to count how many species are in an area, for example, for conservation management purposes."

The researchers used DNA sequencing technology to genotype, or identify, the DNA of thousands of lizards and snakes.

"We have laid down the structure of squamate relationships and yet this is still the beginning," said Dr. Pyron. "As hundreds of new species are described every year from around the glove, this estimate of the squamate tree of life shows us what we do know, and more importantly, what we don't know, and will hopefully spur even more research on the amazing diversity of lizards and snakes."

The research for the project came out of George Washignton University, City University of New York and Arizona State University.

The findings were recently published in the journal BMC Evolutionary Biology.