They came from below: Most modern groups of living snakes evolved from a burrowing ancestor, scientists report today in Biology Letters. The researchers rearranged the snake-and-lizard portion of the reptilian family tree based on a genetic analysis that examined DNA sequences in 44 genes from 161 species—representing most families of lizards and snakes alive today. Most groups of living snakes—including species as diverse as (clockwise from upper left) palm vipers, Indian cobras, green snakes, and timber rattlesnakes—are genetically most closely related to the Anomalepididae family of burrowing blind snakes . The new study is the largest of its kind, the researchers say; previously, the largest such study considered less than half the number of genes and less than one-third the number of species.
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