Conserved but flexible modularity in the zebrafish skull: implications for craniofacial evolvability

Parsons, K. J. , Son, Y. H., Crespel, A., Thambithurai, D., Killen, S. , Harris, M. P. and Albertson, R. C. (2018) Conserved but flexible modularity in the zebrafish skull: implications for craniofacial evolvability. Proceedings of the Royal Society of London Series B: Biological Sciences, 285(1877), 20172671. (doi: 10.1098/rspb.2017.2671) (PMID:29669899) (PMCID:PMC5936725)

Abstract

Morphological variation is the outward manifestation of development and provides fodder for adaptive evolution. Because of this contingency, evolution is often thought to be biased by developmental processes and functional interactions among structures, which are statistically detectable through forms of covariance among traits. This can take the form of substructures of integrated traits, termed modules, which together comprise patterns of variational modularity. While modularity is essential to an understanding of evolutionary potential, biologists currently have little understanding of its genetic basis and its temporal dynamics over generations. To address these open questions, we compared patterns of craniofacial modularity among laboratory strains, defined mutant lines and a wild population of zebrafish ( ). Our findings suggest that relatively simple genetic changes can have profound effects on covariance, without greatly affecting craniofacial shape. Moreover, we show that instead of completely deconstructing the covariance structure among sets of traits, mutations cause shifts among seemingly latent patterns of modularity suggesting that the skull may be predisposed towards a limited number of phenotypes. This new insight may serve to greatly increase the evolvability of a population by providing a range of 'preset' patterns of modularity that can appear readily and allow for rapid evolution.

• Item Type: Articles
• Additional Information: This work was supported by a National Science Foundation (IOS-1054909) and a National Institute of Health Grant to R.C.A, as well as a European Research Council Starter grant to S.K. and a Marie-Curie research fellowship to A.C.
• Keywords: Evolvability, integration, development, mutation.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Killen, Professor Shaun and Thambithurai, Davide and Crespel, Dr Amelie and Parsons, Dr Kevin
• Authors: Parsons, K. J., Son, Y. H., Crespel, A., Thambithurai, D., Killen, S., Harris, M. P., and Albertson, R. C.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Proceedings of the Royal Society of London Series B: Biological Sciences
• Publisher: The Royal Society
• ISSN: 0962-8452
• ISSN (Online): 1471-2954
• Published Online: 18 April 2018
• Copyright Holders: Copyright © 2018 The Authors
• First Published: First published in Proceedings of the Royal Society of London Series B: Biological Sciences 285(1877): 20172671
• Publisher Policy: Reproduced in accordance with the publisher copyright policy