On the relationship between ontogenetic and static allometry.
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.
Centre for Conservation Biology, Department of Biology, University of Science and Technology NTNU, 7491 Trondheim, Norway. christophe.pelabon@ntnu.no
Christophe
C
Pélabon
Geir H
GH
Bolstad
Camilla K
CK
Egset
James M
JM
Cheverud
Mihaela
M
Pavlicev
Gunilla
G
Rosenqvist
D000704:Analysis of Variance; D000818:Animals; D005075:Biological Evolution; D049628:Body Size / Q000502:physiology*; D001837:Body Weights and Measures; D003198:Computer Simulation; D048788:Growth and Development / Q000502:physiology*; D051379:Mice; D008954:Models, Biological; D011036:Poecilia / Q000254:growth & development; D019655:Quantitative Trait, Heritable; D012641:Selection, Genetic; D013623:Tail / Q000254:growth & development