Foraging mode constrains the evolution of cephalic horns in lizards and snakes.

A phylogenetically diverse minority of snake and lizard species exhibit rostral and ocular appendages that substantially modify the shape of their heads. These cephalic horns have evolved multiple times in diverse squamate lineages, enabling comparative tests of hypotheses on the benefits and costs of these distinctive traits. Here, we demonstrate correlated evolution between the occurrence of horns and foraging mode.

Stronger evidence for genetic ancestry than environmental conditions in shaping the evolution of a complex signalling trait during biological invasion.

Introductions of invasive species to new environments often result in rapid rates of trait evolution. While in some cases these evolutionary transitions are adaptive and driven by natural selection, they can also result from patterns of genetic and phenotypic variation associated with the invasion history. Here, we examined the brown anole (Anolis sagrei), a widespread invasive lizard for which genetic data have helped trace the sources of non-native populations.

When adaptation is slowed down: Genomic analysis of evolutionary stasis in thermal tolerance during biological invasion in a novel climate.

Research conducted during the past two decades has demonstrated that biological invasions are excellent models of rapid evolution. Even so, characteristics of invasive populations such as a short time for recombination to assemble optimal combinations of alleles may occasionally limit adaptation to new environments. Here, we investigated such genetic constraints to adaptation in the invasive brown anole (Anolis sagrei)-a tropical ectotherm that was introduced to the southeastern United States, a region with a much colder climate than in its native Caribbean range.

Upper beak depression instead of elevation dominates cranial kinesis in woodpeckers.

The value of birds' ability to move the upper beak relative to the braincase has been shown in vital tasks like feeding and singing. In woodpeckers, such cranial kinesis has been thought to hinder pecking as delivering forceful blows calls for a head functioning as a rigid unit. Here, we tested whether cranial kinesis is constrained in woodpeckers by comparing upper beak rotation during their daily activities such as food handling, calling and gaping with those from closely related species that also have a largely insectivorous diet but do not peck at wood.

Rapidly evolved traits enable new conservation tools: perspectives from the cane toad invasion of Australia.

Natural populations can show rapid adaptive responses to intense (human-mediated) environmental change. The potential for exploiting rapidly evolved traits for conservation management has been often discussed but rarely implemented. Capitalizing on a well-studied biological invasion, we here explore the idea that rapid phenotypic change in the invaders, their pathogens, and the native biota provide opportunities for managers to control invader abundance and buffer adverse impacts on native wildlife.

Protein-lipid Association in Lizard Chemical Signals.

Chemical communication in terrestrial vertebrates is often built on complex blends, where semiochemical and structural compounds may form an integrated functional unit. In lizards, many species have specialized epidermal glands whose secretions are waxy, homogeneous blends of lipids and proteins, both active in communication. The intimate co-occurrence of such compounds allows us to hypothesize that they should undergo a certain degree of covariation, considering both their semiochemical role and the support-to-lipid function hypothesized for the protein fraction.

Introduction history and hybridization determine the hydric balance of an invasive lizard facing a recent climate niche shift.

As anthropogenic activities are increasing the frequency and severity of droughts, understanding whether and how fast populations can adapt to sudden changes in their hydric environment is critically important. Here, we capitalize on the introduction of the Cuban brown anole lizard (Anolis sagrei) in North America to assess the contemporary evolution of a widespread terrestrial vertebrate to an abrupt climatic niche shift. We characterized hydric balance in 30 populations along a large climatic gradient.

Digest: environmental variability as a constraint on cognitive evolution in lizards.

How does ecology influence cognitive evolution in lizards? Taking a comparative approach, De Meester et al. (2022) discovered that species living in temporally fluctuating environments tend to perform relatively poorly on cognitive tasks associated with behavioral flexibility compared to species living in more climatically stable environments. The negative association between environmental variability and cognitive performance suggests that stochastic environments can hamper, rather than stimulate, the evolution of cognitive ability.

Chromosome-Level Genome Assembly of the Cape Cliff Lizard (Hemicordylus capensis).

Squamates represent a highly diverse and species-rich vertebrate group that is remarkably understudied from a genomic perspective. A scarcity of genomic data is particularly evident for scincomorph lizards, which encompass over 10% of all living squamates, and for which high-quality genomic resources are currently lacking. To address this knowledge gap, we present the first chromosome-level reference genome for this group, generated from a male Cape cliff lizard (Hemicordylus capensis), using highly accurate PacBio HiFi long-read sequencing data, long-range Omni-C chromosomal conformation capture data and transcriptomic data for annotation.

Parallel evolution of semicircular canal form and sensitivity in subterranean mammals.

The vertebrate vestibular system is crucial for balance and navigation, and the evolution of its form and function in relation to species' lifestyle and mode of locomotion has been the focus of considerable recent study. Most research, however, has concentrated on aboveground mammals, with much less published on subterranean fauna. Here, we explored variation in anatomy and sensitivity of the semicircular canals among 91 mammal species, including both subterranean and non-subterranean representatives.

How to behave when marooned: the behavioural component of the island syndrome remains underexplored.

Animals on islands typically depart from their mainland relatives in assorted aspects of their biology. Because they seem to occur in concert, and to some extent evolve convergently in disparate taxa, these changes are referred to as the 'island syndrome'. While morphological, physiological and life-history components of the island syndrome have received considerable attention, much less is known about how insularity affects behaviour.

Changes in selection pressure can facilitate hybridization during biological invasion in a Cuban lizard.

Hybridization is among the evolutionary mechanisms most frequently hypothesized to drive the success of invasive species, in part because hybrids are common in invasive populations. One explanation for this pattern is that biological invasions coincide with a change in selection pressures that limit hybridization in the native range. To investigate this possibility, we studied the introduction of the brown anole () in the southeastern United States.

Convergent evolution of skin surface microarchitecture and increased skin hydrophobicity in semi-aquatic anole lizards.

Animals that habitually cross the boundary between water and land face specific challenges with respect to locomotion, respiration, insulation, fouling and waterproofing. Many semi-aquatic invertebrates and plants have developed complex surface microstructures with water-repellent properties to overcome these problems, but equivalent adaptations of the skin have not been reported for vertebrates that encounter similar environmental challenges. Here, we document the first evidence of evolutionary convergence of hydrophobic structured skin in a group of semi-aquatic tetrapods.

Investment in chemical signalling glands facilitates the evolution of sociality in lizards.

The evolution of sociality and traits that correlate with, or predict, sociality, have been the focus of considerable recent study. In order to reduce the social conflict that ultimately comes with group living, and foster social tolerance, individuals need reliable information about group members and potential rivals. Chemical signals are one such source of information and are widely used in many animal taxa, including lizards.

Hurricane effects on Neotropical lizards span geographic and phylogenetic scales.

Extreme climate events such as droughts, cold snaps, and hurricanes can be powerful agents of natural selection, producing acute selective pressures very different from the everyday pressures acting on organisms. However, it remains unknown whether these infrequent but severe disruptions are quickly erased by quotidian selective forces, or whether they have the potential to durably shape biodiversity patterns across regions and clades. Here, we show that hurricanes have enduring evolutionary impacts on the morphology of anoles, a diverse Neotropical lizard clade.

The island syndrome.

Simon Baeckens and Raoul Van Damme introduce the phenotypic changes animals and plants undergo when inhabiting islands.

Convergent Evolution of Claw Shape in a Transcontinental Lizard Radiation.

Species occupying similar selective environments often share similar phenotypes as the result of natural selection. Recent discoveries, however, have led to the understanding that phenotypes may also converge for other reasons than recurring selection. We argue that the vertebrate claw system constitutes a promising but understudied model system for testing the adaptive nature of phenotypic, functional, and genetic convergence.

Where to do number two: Lizards prefer to defecate on the largest rock in the territory.

Many animals use their excrements to communicate with others. In order to increase signal efficacy, animals often behaviourally select for specific defecation sites that maximize the detectability of their faecal deposits, such as the tip of rocks by some lizard species. However, the field conditions in which these observations are made make it difficult to reject alternative explanations of defecation site preference; rock tips may also provide better opportunities for thermoregulation, foraging, or escaping predators, and not solely for increasing the detectability of excrements.

Ontogenetic scaling patterns of lizard skin surface structure as revealed by gel-based stereo-profilometry.

The skin surface structure of squamate reptiles varies greatly among species, likely because it plays a key role in a range of tasks, such as camouflage, locomotion, self-cleaning, mitigation of water loss and protection from physical damage. Although we have foundational knowledge about squamate skin morphology, we still know remarkably little about how intraspecific variation in skin surface structure translates to functional variation. This gap in our understanding can be in part traced back to: (i) our lack of knowledge on how body size determines skin surface structure; and (ii) the lack of means to perform high-throughput and detailed analysis of the three-dimensional (3D) anatomy of reptilian skin surfaces in a non-destructive manner.

Habitat use and vestibular system's dimensions in lacertid lizards.

The vestibular system is crucial for movement control during locomotion. As the dimensions of the vestibular system determine the fluid dynamics of the endolymph and, as such, the system's function, we investigate the interaction between vestibular system size, head size and microhabitat use in lizards. We grouped 24 lacertid species in three microhabitat types, we acquired three-dimensional models of the bony vestibular systems using micro-computer tomography scanning, and we performed linear and surface measurements.

Digest: Evolution of shape and leverage of bird beaks reflects feeding ecology, but not as strongly as expected.

Is feeding ecology the main driver of beak diversification in modern birds? Taking a broad-scale interspecific comparative approach, Navalón et al. (2019) found a relationship between feeding ecology (diet and feeding behavior) and beak morphology (shape and leverage), although much of the observed variation remained unexplained. This low explanatory power may suggest that variation in the multitude of nonfeeding functions of the beak also influences its evolution.

The brown anole dewlap revisited: do predation pressure, sexual selection, and species recognition shape among-population signal diversity?

Animal signalling structures are amongst the most variable characteristics, as they are subjected to a diversity of selection pressures. A well-known example of a diverse signalling system in the animal kingdom is the dewlap of lizards. Dewlap characteristics can vary remarkably among and within species, and also between sexes.