News Finding: "It was during this Cambrian period that many of the most familiar traits associated with this group of animals evolved, like a hard exoskeleton, jointed legs, and compound (multi-faceted) eyes that are shared by all arthropods.
Paper Finding: The elevated Cambrian rates of phenotypic evolution are unlikely to be an artifact of oversampling of characters changing on early arthropod branches, for two reasons.
News Context: Their modelling showed that moderately accelerated evolution was sufficient to explain the seemingly sudden appearance of many groups of advanced animals in the fossil record during the Cambrian explosion. "It was during this Cambrian period that many of the most familiar traits associated with this group of animals evolved, like a hard exoskeleton, jointed legs, and compound (multi-faceted) eyes that are shared by all arthropods. We even find the first appearance in the fossil record of the antenna that insects, millipedes and lobsters all have, and the earliest biting jaws."
Paper Context: Such scenarios do not predict that genes involved in basic metabolic and cellular processes common to all panarthropods should have faster evolutionary rates in earlier panarthropod lineages. The elevated Cambrian rates of phenotypic evolution are unlikely to be an artifact of oversampling of characters changing on early arthropod branches, for two reasons. Second, the molecular data exhibit an almost identical Cambrian rate burst yet cannot suffer such ascertainment bias (because gene sequencing samples every single nucleotide in a gene region, not just sites changing on particular branches).