To estimate the relative timing of origins, diversification, body form evolution and transition in habitat, Bayesian molecular dating methods were implemented in BEAST v1.5.2 (Bayesian evolutionary analysis by sampling trees) [ 111].
A primary concern is whether the pattern indicated by analyses such as those of Wiens and Slingluff [ 4] and Brandley et al. [ 5], specifically, moderately frequent limb loss occurring over extended intervals (usually tens of millions of years) with occasional re-elaboration of limbs, accurately represents the evolution of body form in squamates.
The convergent evolution of the limuloid body form in unrelated myrmecophilous taxa provides strong evidence of its adaptive value [ 54].
Many authors have noted the recurring evolution of an elongate, limb-reduced body form in squamates, however, even within this clade, the frequency and rate of limb reduction inferred here for Lerista are exceptional.
Reproductive modes, ontogenies, and the evolution of body form.
Their analyses revealed a consistent association of decreases in limb length, digit loss, and body elongation across ecologically and phylogenetically diverse squamate clades, indicating an influence of shared functional and developmental constraints on the evolution of body form.
Some of the more tantalizing examples of parallel evolution found in vertebrates include the evolution of distinct body forms of freshwater fishes in different habitats [ 3- 6], lizard ecomorphs on different islands [ 7- 9], recurring phenotypes of cichlids in African Rift Lakes [ 10- 12], and distinct body forms and life history traits found along predation gradients [ 13- 16].
Saltatory evolution of new body forms can occur in multi-cellular organisms because a mutation in a single developmental gene can cause large changes in body form.
Transition from a lizard-like to a snake-like body form is one of the most important transformations in reptilian evolution.
