Morphological evolution in Tropidurinae squamates: an integrated view along a continuum of ecological settings

Abstract

Variation in squamate foot morphology is likely relevant during evolutionary processes of habitat colonization because distinct surfaces differ in energetic and functional demands for locomotion. We combined new foot morphological data with published information of limb and tail lengths to investigate evolutionary changes possibly associated with the differential usage of ecological settings by Tropidurinae species. Several traits exhibited significant phylogenetic signal, and we performed conventional and phylogenetic regressions of PC scores (retained from Principal Components Analyses of morphometric traits) on continuous ecological indices. Tropidurines from sandy habitats exhibit larger foot soles, opposite to the evolution of narrow feet in species that use branches and rocks. Also, species that usually move along trunks present longer femora. This study provides evidence for morphological adaptations associated with substrate usage in Tropidurinae, and suggests that opposite morphological profiles might evolve associated with the use of surfaces energetically and functionally contrasting, possibly leading to trade-offs.

Etho-Eco-Morphological Mismatches, an Overlooked Phenomenon in Ecology, Evolution and Evo-Devo That Supports ONCE (Organic Nonoptimal Constrained Evolution) and the Key Evolutionary Role of Organismal Behavior

“…Abdala et al (2014) recognized this somewhat when they stated that "the overwhelming effect of phylogeny in shaping morphology has been repeatedly obtained in studies of various taxa" and of many different structures, such as the external anatomy of lacertids (Vanhooydonck and Van Damme, 1999) and skinks (Goodman et al, 2008) and liolaemids (Schulte et al, 2004;Tulli et al, 2009), thermal biology of liolaemids , and internal morphology of geckos and liolaemids (Zaaf et al, 1999;Tulli et al, 2012). Moreover, similar results were obtained for tendinous tissue in iguanid lizards (Tulli et al, 2011), and forelimb traits in tropidurid lizards (Grizante et al, 2010). Abdala et al (2014, p. 397) thus conclude that "it appears that the Bauplan of the lizard pes incorporates a morphological configuration that is sufficiently versatile to enable exploitation of almost all of the available habitats; as unexpected as conservation of internal gross morphology appears, it represents a means of accommodating to environmental challenges by apparently permitting adequacy for all situations examined."…”

Claw morphometrics in monitor lizards: Variable substrate and habitat use correlate to shape diversity within a predator guild

“…Morphological adaptations associated with substrate usage are often reflected in locomotor traits (Grizante, Navas, Garland, & Kohlsdorf, 2010; Losos, 1990b; Vanhooydonck, Andronescu, Herrel, & Irschick, 2005). Claws are therefore well studied, as they are often the first and last structure to interface with substrate during locomotion (Birn‐Jeffery, Miller, Naish, Rayfield, & Hone, 2012).…”

Evolution of Sexual Dimorphism in the Digit Ratio 2D:4D - Relationships with Body Size and Microhabitat Use in Iguanian Lizards

“…Anurans: [1]–[5], Reptiles: [6]–[13], Mammals: [14]–[19]), although information about the mechanisms that probably elicit evolutionary changes in morphology during a process of ecological divergence is still scarce and restricted to few biological groups (for examples see [20], [21]). Evolutionary changes in the shape and size of a given structure are believed to reside on alterations that occurred during embryo development [22]–[27], but the evolution of morphological variation is very often inferred from adult morphologies, probably because in nature embryos are usually hard to access.…”

“…Evolution of autopodium morphology in the context of habitat usage is particularly well investigated in squamates, where evolution of limb and foot lengths seems clearly associated with locomotion on different surfaces (e.g. [9], [11], [13], [53], [57]–[59]). Lizards constitute a great model for the investigation of this relationship because of their extensive morphological variation, great ecological diversity, and broad use of different locomotor modes, such as running, jumping, and climbing (e.g.…”

“…[60]–[65]). Moreover, associations between morphology and ecology have been reported in several families, as Polychrotidae (particularly Anolis [6], [7], [57], [66]–[68]), Iguanidae [69], and Tropiduridae [9], [10], [13], [64], [70]–[72]. Some studies suggest for example that species from sandy environments exhibit longer feet (e.g.…”