title: Evolution of segmentation: rolling back the clock.
abstract: Recent work has revealed striking similarities in the genetic mechanisms underpinning somitogenesis in zebrafish and segmentation in the spider. Could this mean that the bilaterian common ancestor was segmented after all?
mesh_terms: D000818:Animals; D005075:Biological Evolution; D019521:Body Patterning; D004625:Embryo, Nonmammalian / Q000196:embryology*; D008954:Models, Biological; D010802:Phylogeny; D019170:Somites / Q000378:metabolism*; D013112:Spiders / Q000196:embryology*; D015027:Zebrafish / Q000196:embryology*