Neurophylogeny: Retracing Early Metazoan Brain Evolution

摘要: The current view of early metazoan phylogeny suggests that the bilaterian body plan arose only once during evolution. This first urbilaterian animal was most likely equipped with an anterior condensation nerve cells – a brain from which all brains modern animals have diverged. Until recently, ancestor phyla viewed as very simple accordingly brain. Molecular studies, however, demonstrate multitude homologous genes are expressed in similar patterns developing vertebrates, insects, and annelids. Taken together, these findings imply anatomy cerebrum might been more elaborate than previously assumed. If true, ancient architectural features conserved evolution should be identifiable distantly related phyla. Comparative studies on representatives arthropods, onychophorans, annelids suggest this is indeed case. chapter summarizes recent neuroanatomical surveys aim to retrace use data test conflicting hypothesis phylogenetic relationships between major