title: In search of morphological modules: a systematic review.
abstract: Morphological modularity arises in complex living beings due to a semi-independent inheritance, development, and function of body parts. Modularity helps us to understand the evolvability and plasticity of organismal form, and how morphological variation is structured during evolution and development. For this reason, delimiting morphological modules and establishing the factors involved in their origins is a lively field of inquiry in biology today. Although it is thought that modularity is pervasive in all living beings, actually we do not know how often modularity is present in different morphological systems. We also do not know whether some methodological approaches tend to reveal modular patterns more easily than others, or whether some factors are more related to the formation of modules or the integration of the whole phenotype. This systematic review seeks to answer these type of questions through an examination of research investigating morphological modularity from 1958 to present. More than 200 original research articles were gathered in order to reach a quantitative appraisal on what is studied, how it is studied, and how the results are explained. The results reveal an heterogeneous picture, where some taxa, systems, and approaches are over-studied, while others receive minor attention. Thus, this review points out various trends and gaps in the study of morphological modularity, offering a broad picture of current knowledge and where we can direct future research efforts.
authors.affiliation: Department of Comparative Biomedical Sciences, Royal Veterinary College, Hawkshead Lane, North Mymms, Hatfield, Hertfordshire AL9 7TA, UK.|Department of Anatomy, College of Medicine, Howard University, 520 W Street, NW, Numa Adams Building, Washington, DC 20059, USA.
authors.forename: Borja
authors.identifier: http://orcid.org/0000-0002-6645-4684
authors.initials: B
authors.lastname: Esteve-Altava
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001699:Biometry; D008954:Models, Biological; D010641:Phenotype
keywords: EvoDevo; developmental modules; functional modules; morphological modularity; phenotypic integration