title: Complex Homology and the Evolution of Nervous Systems.
abstract: We examine the complex evolution of animal nervous systems and discuss the ramifications of this complexity for inferring the nature of early animals. Although reconstructing the origins of nervous systems remains a central challenge in biology, and the phenotypic complexity of early animals remains controversial, a compelling picture is emerging. We now know that the nervous system and other key animal innovations contain a large degree of homoplasy, at least on the molecular level. Conflicting hypotheses about early nervous system evolution are due primarily to differences in the interpretation of this homoplasy. We highlight the need for explicit discussion of assumptions and discuss the limitations of current approaches for inferring ancient phenotypic states.
authors.affiliation: Center for Systems and Synthetic Biology, University of Texas, Austin, TX 78712, USA; Institute for Cellular and Molecular Biology, University of Texas, Austin, TX 78712, USA; Center for Computational Biology and Bioinformatics, University of Texas, Austin, TX 78712. Electronic address: bliebeskind@austin.utexas.edu.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Liebeskind
authors.affiliation: Institute for Cellular and Molecular Biology, University of Texas, Austin, TX 78712, USA; Center for Computational Biology and Bioinformatics, University of Texas, Austin, TX 78712; Department of Integrative Biology, University of Texas, Austin, TX 78712, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Hillis
authors.affiliation: Institute for Cellular and Molecular Biology, University of Texas, Austin, TX 78712, USA; Center for Computational Biology and Bioinformatics, University of Texas, Austin, TX 78712; Department of Integrative Biology, University of Texas, Austin, TX 78712, USA; Department of Neuroscience, University of Texas, Austin, TX 78712, USA; Institute for Neuroscience, University of Texas, Austin, TX 78712, USA; Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, MA 02543, USA.
authors.forename: Harold H
authors.initials: HH
authors.lastname: Zakon
authors.affiliation: Institute for Cellular and Molecular Biology, University of Texas, Austin, TX 78712, USA; Center for Computational Biology and Bioinformatics, University of Texas, Austin, TX 78712; Department of Integrative Biology, University of Texas, Austin, TX 78712, USA; Department of Neuroscience, University of Texas, Austin, TX 78712, USA; Institute for Neuroscience, University of Texas, Austin, TX 78712, USA.
authors.forename: Hans A
authors.initials: HA
authors.lastname: Hofmann
mesh_terms: D000818:Animals; D044822:Biodiversity; D005075:Biological Evolution; D005786:Gene Expression Regulation; D006801:Humans; D009420:Nervous System / Q000033:anatomy & histology*