Snakes may have legs before. The present 3,400 modern species existing today may have the same prehistoric progenitor with real toes and ankles, according to researchers on Tuesday.
After evaluating the data they have collected by using genetic sequencing using fossils, added to it the anatomical comparison of 73 lizard and snake species, Yale University’s paleontologist team has created what it calls the most complete snake “family tree ever yet. The research has the answer all the questions regarding where and how the modern snakes existed
“Having that tree as a backbone let us draw a ton of conclusions for what the ancestral snake would have been like,” said Daniel J. Field, a doctoral candidate in evolutionary biology and an author of the study. The team concluded that the most recent common ancestor of all living snakes was nocturnal, thrived 128.5 million years ago in the Southern Hemisphere and devoured relatively large prey whole using its sharp, hooked teeth as a hunting tool.
For them to reach this conclusion, what the team did first was to rebuild the snakes’ family tree from the tip to the trunk. To really get an idea when some characteristics developed , such as how they hunt their preys at night, their constricting ability, how they first came into use, researchers utilized the genetic and morphological information that they gathered and assembled together pieces of information , how the several groups of snakes became related to each other.
After collating the relationships among the different groups, the herpetologists utilized different algorithms to put the right data where it belonged. Things such as when a certain characteristic showed up in what they called ancestral state reconstruction process. Mr. Field and his group identified 11 traits that they wanted to insert in the tree of life. Each of the characteristic would correspond to a certain question concerning the snakes’ evolutionary process that scientists often come to debate. Are the snakes water or land dwellers? Are they from the southern part or form the north? Do they ambush their prey
“I was most amazed by how strongly we inferred that the common ancestor retained hind limbs,” he said. The team published its tree of life for snakes in the journal BMC Evolutionary Biology.
“Sometimes evolution plays out in unexpected and strange ways,” he said. “We think we’ve got a strongly supported idea, and based on the mathematical reconstruction it is what is most likely to be true.”