On the Relationship between Ontogenetic and Static Allometry

• Published in: The American naturalist 2013-02, Vol.181 (2), p.195-212
• Main Authors: Pélabon, Christophe, Bolstad, Geir H., Egset, Camilla K., Cheverud, James M., Pavlicev, Mihaela, Rosenqvist, Gunilla
• Format: Article
• Language: English
• Subjects: Agnatha. Pisces; Allometry; Analysis of Variance; Anatomy & physiology; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Biological and medical sciences; Biological Evolution; Body size; Body Size - physiology; Body Weights and Measures; Computer Simulation; Covariance; Developmental stages; Evolution; Fresh water ecosystems; Fundamental and applied biological sciences. Psychology; General aspects; Genetics; Growth and Development - physiology; Growth traits; Mice; Modeling; Models, Biological; Ontogeny; Organisms; Parametric models; Poecilia - growth & development; Population mean; Quantitative Trait, Heritable; Selection, Genetic; Synecology; Tail - growth & development; Tangents; Variances; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution
• ISSN: 0003-0147; 1537-5323
• DOI: 10.1086/668820

Ontogenetic and static allometries describe how a character changes in size when the size of the organism changes during ontogeny and among individuals measured at the same developmental stage, respectively. Understanding the relationship between these two types of allometry is crucial to understanding the evolution of allometry and, more generally, the evolution of shape. However, the effects of ontogenetic allometry on static allometry remain largely unexplored. Here, we first show analytically how individual variation in ontogenetic allometry and body size affect static allometry. Using two longitudinal data sets on ontogenetic and static allometry, we then estimate variances and covariances for the different parameters of the ontogenetic allometry defined in our model and assess their relative contribution to the static allometric slope. The mean ontogenetic allometry is the main parameter that determines the static allometric slope, while the covariance between the ontogenetic allometric slope and body size generates most of the discrepancies between ontogenetic and static allometry. These results suggest that the apparent evolutionary stasis of the static allometric slope is not generated by internal (developmental) constraints but more likely results from external constraints imposed by selection.