An article published in the journal “BMC Biology” describes a genetic research that shows a whole genome duplication (WGD) during the evolution of arachnids. An international team of researchers in collaboration with the Human Genome Sequencing Center at Baylor College of Medicine analyzed the DNA of the common house spider (Parasteatoda tepidariorum) and the Arizona bark scorpion, Centruroides sculpturatus, concluding that they descended from a common ancestor that lived more than 450 million years ago.