On the lack of a universal pattern associated with mammalian domestication: differences in skull growth trajectories across phylogeny

Abstract

As shown in a taxonomically broad study, domestication modifies postnatal growth. Skull shape across 1128 individuals was characterized by 14 linear measurements, comparing 13 pairs of wild versus domesticated forms. Among wild forms, the boar, the rabbit and the wolf have the highest proportion of allometric growth, explaining in part the great morphological diversity of the domesticated forms of these species. Wild forms exhibit more isometric growth than their domesticated counterparts. Multivariate comparisons show that dogs and llamas exhibit the greatest amount of differences in trajectories with their wild counterparts. The least amount is recorded in the pig–boar, and camel and horse pairs. Bivariate analyses reveal that most domesticated forms have growth trajectories different from their respective wild counterparts with regard to the slopes. In pigs and camels slopes are shared and intercepts are different. There is a trajectory extension in most domesticated herbivores and the contrary pattern in carnivorous forms. However, there is no single, universal and global pattern of paedomorphosis or any other kind of heterochrony behind the morphological diversification that accompanies domestication.

The evolution of ontogenetic allometric trajectories in mammalian domestication

“…), and the first study to date to examine postnatal growth trajectories in domesticated mammals across a broad sample of clades has indicated the presence of types of heterochrony, but an absence of a universal pattern of change (Sánchez‐Villagra et al. ). Those results emphasize the potential for changes in growth pattern to arise prenatally (Geiger et al.…”

Prenatal allometric trajectories and the developmental basis of postcranial phenotypic diversity in bats (Chiroptera)

“…This is underscored by the values of allometric disparity in each suborder. Differences in allometric disparity have helped to describe evolutionary differences between closely‐related taxa in mammals (Sánchez‐Villagra et al, ; Wilson, ; Wilson & Sánchez‐Villagra, ). Greater disparity in our yinpterochiropteran sample indicates that the developmental trajectories in this group may not be evolutionarily constrained, leading to diversification in the morphogenetic processes of the species (Wilson, ; Wilson & Sánchez‐Villagra, ).…”

“…Developmental trajectories are generally thought of as being highly conserved between sister taxa (Hautier et al, ). However, deep‐rooted divergences allow for different developmental mechanisms to evolve between closely‐related taxa (Sánchez‐Villagra et al, ; Wilson, ). The early divergence of bat suborders could have allowed the evolution of differences in the ontogenetic allometric trajectories between suborders.…”

“…An alternative approach for the analysis of morphogenesis is the study of allometry within a phenotypic space (Gerber, Eble, & Neige, ; Klingenberg, ; Sánchez‐Villagra et al, ; Wilson, a; Wilson & Sánchez‐Villagra, ). Size‐dependent growth is intrinsic to the development of an organism, and changes in size‐dependent development can reflect ecomorphological diversity within a clade (Klingenberg, ).…”

“…Recent studies have proposed novel multidimensional interpretations of allometry, compiling the developmental trajectories of multiple structures into a multivariate, allometric space (Randau & Goswami, , ; Wilson, a; Wilson & Sánchez‐Villagra, ). Allometric spaces facilitate the quantification of variation in the developmental trajectories of different taxa (i.e., allometric polarity), enabling the depiction of an ontogenetic signal in evolutionary processes (Adams & Nistri, ; Gerber et al, ; Sánchez‐Villagra et al, ; Wilson & Sánchez‐Villagra, ). The distribution of species within an allometric space can yield information on the evolutionary origin of apomorphies in a phylogeny (Adams & Nistri, ), ontogenetic signals in the ecologic partitioning of a group (Wilson & Sánchez‐Villagra, ), and the evolutionary changes in the development of different organisms in response to ecological pressures (Sánchez‐Villagra et al, ; Wilson & Sánchez‐Villagra, ; Wilson, ).…”