naa a22 4500 510780563 CHVBK 20180411083245.0 cr unu---uuuuu 180411e20130601xx s 000 0 eng 10.1007/s11692-012-9200-9 doi (NATIONALLICENCE)springer-10.1007/s11692-012-9200-9 Structural Constraints in the Evolution of the Tetrapod Skull Complexity: Williston's Law Revisited Using Network Models [Elektronische Daten] [Borja Esteve-Altava, Jesús Marugán-Lobón, Héctor Botella, Diego Rasskin-Gutman] Ever since the appearance of the first land vertebrates, the skull has undergone a simplification by loss and fusion of bones in all major groups. This well-documented evolutionary trend is known as "Williston's Law”. Both loss and fusion of bones are developmental events that generate, at large evolutionary scales, a net reduction in the number of skull bones. We reassess this evolutionary trend by analyzing the patterns of skull organization captured in network models in which nodes represent bones and links represent suture joints. We also evaluate the compensatory process of anisomerism (bone specialization) suggested to occur as a result of this reduction by quantifying the heterogeneity and the ratio of unpaired bones in real skulls. Finally, we perform simulations to test the differential effect of bone losses in skull evolution. We show that the reduction in bone number during evolution is accompanied by a trend toward a more complex organization, rather than toward simplification. Our results indicate that the processes by which bones are lost or fused during development are central to explain the evolution of the morphology of the skull. Our simulations suggest that the evolutionary trend of increasing morphological complexity can be caused as a result of a structural constraint, the systematic loss of less connected bones during development. Springer Science+Business Media, LLC, 2012 Morphological complexity nationallicence Constraints nationallicence Network theory nationallicence Tetrapod skull nationallicence Esteve-Altava Borja Theoretical Biology Research Group, Institute Cavanilles for Biodiversity and Evolutionary Biology, University of Valencia, 46071, Valencia, Spain aut Marugán-Lobón Jesús Unidad de Paleontología, Dpto. Biología, Universidad Autónoma de Madrid, 28049, Cantoblanco, Spain aut Botella Héctor Area de Paleontología, Dpto. Geología, University of Valencia, 46100, Valencia, Spain aut Rasskin-Gutman Diego Theoretical Biology Research Group, Institute Cavanilles for Biodiversity and Evolutionary Biology, University of Valencia, 46071, Valencia, Spain aut Evolutionary Biology Springer US; http://www.springer-ny.com 40/2(2013-06-01), 209-219 0071-3260 40:2<209 2013 40 11692 https://doi.org/10.1007/s11692-012-9200-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11692-012-9200-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Esteve-Altava Borja Theoretical Biology Research Group, Institute Cavanilles for Biodiversity and Evolutionary Biology, University of Valencia, 46071, Valencia, Spain aut NATIONALLICENCE 700 1- Marugán-Lobón Jesús Unidad de Paleontología, Dpto. Biología, Universidad Autónoma de Madrid, 28049, Cantoblanco, Spain aut NATIONALLICENCE 700 1- Botella Héctor Area de Paleontología, Dpto. Geología, University of Valencia, 46100, Valencia, Spain aut NATIONALLICENCE 700 1- Rasskin-Gutman Diego Theoretical Biology Research Group, Institute Cavanilles for Biodiversity and Evolutionary Biology, University of Valencia, 46071, Valencia, Spain aut NATIONALLICENCE 773 0- Evolutionary Biology Springer US; http://www.springer-ny.com 40/2(2013-06-01), 209-219 0071-3260 40:2<209 2013 40 11692 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer