Evolutionary Developmental Biology, Volume 141, the latest release in the Current Topics in Developmental Biology series highlights new advances in the field, with this new volume presenting interesting chapters on a variety of important topics, including Enhancer modularity, New cell types in evolution, Homology and Innovation, Plasticity and Genetic assimilation, Sympoiesis, Development through Symbiosis, Axes and Segmentation in Invertebrates, Transitional chordates and vertebrate origins: Urochordates, Transitional chordates and vertebrate origins: Hemichordates, Transitional chordates and vertebrate origins: Cephalochordates, Origin and Evolution of Jawed Vertebrates, Origin and Evolution of the Vertebrate Skull, and Development of Eusocial Insects.