Biology subjects

Horta-Lacueva, Q. J.-B.

Publications and source records attributed to Horta-Lacueva, Q. J.-B..

4 recordsLinked to original sources

bioRxiv2025

Neural crest cell biology shapes lizard skull evolution across evolutionary time scales

The vertebrate skull originates from two embryonic lineages, the mesoderm and the neural crest, offering a unique framework to study how developmental mechanisms connect phenotypic variation and evolutionary diversification. Using 3D geometric morphometrics, we analysed skull shape variation in lacertid lizards. Mesoderm- and neural crest-derived bones formed distinct, conserved modules at both micro- and macroevolutionary scales. In the common wall lizard (Podarcis muralis), rapid evolution of skull shape under sexual selection was primarily driven by neural crest-derived bones. While the primary axis of shape divergence in P. muralis aligned with a major axis of variation across lacertids, neural crest-derived bones exhibited slower evolutionary rates and lower morphological disparity than mesodermal-derived bones. We propose that this discrepancy between the role of the neural crest for skull evolution on micro- and macroevolution reflects constraints imposed by neural crest cell biology: although developmental plasticity enables rapid, correlated responses under sexual selection, pleiotropy may limit long-term evolvability of neural crest-derived skull regions. Teaser textThe bones of the vertebrate skull come from two developmental sources: the mesoderm and the neural crest. This dual origin allows to study how development influences evolution. Using 3D models of lizard skulls--including a species with exaggerated male traits linked to the neural crest--we examined patterns of skull variation. We found that neural crest-derived bones contribute to rapid changes driven by sexual selection. However, across different species, these same skull regions evolve more slowly and show less variation. This suggests that while neural crest cells may constrain long-term evolution because of their wide influence, they can also enable fast adaptations. The developmental biology of a trait therefore shapes its evolution.

evolutionary biology↗

bioRxiv2021

The dynamic ontogenetic patterns of adaptive divergence and sexual dimorphism in Arctic charr

Arctic charr (Salvelinus alpinus) in lake Thingvallavatn (Iceland) is one of the most iconic examples of post-glacial adaptive divergence, resulting in four ecomorphs that diverge along the ecological benthic-limnetic axis (bottom lake versus open water feeders), and are distinct both phenotypically and genotypically. Here, we used geometric morphometrics tools on a common garden setup to determine the factors responsible for genetically based shape variation during the post-embryonic ontogeny of two morphs that represent the benthic-limnetic axis: the small benthic (SB) and the planktivorous (PL). This experiment uses pure crosses and F1 reciprocal hybrids between the two morphs, and includes the onset of sexual maturation, offering an excellent opportunity to explore the genetic component of adaptive divergence and the role of sexual dimorphism in this scenario. We found that growth is the main driver of shape variation across time and provided evidence of a genetically-controlled ontogenetic shift that gives rise to the limnetic morph. Additionally, our results indicate that the onset of sexual maturation triggers differences both in sex ontogenetic trajectories and in static shape variation at different time points, likely dissipating the canalisation for traits traditionally associated with benthic-limnetic adaptations.

evolutionary biology↗

bioRxiv2020

Multivariate distributions of behavioural, morphological, and ontogenetic traits in hybrids bring new insights into the divergence of sympatric Arctic charr morphs.

Studying the development of fitness related traits in hybrids from populations diverging in sympatry is a fundamental approach to understand the processes of speciation. However, such traits are often affected by covariance structures that complicate the comprehension of these processes, especially because the interactive relationships between traits of different nature (e.g. morphology, behaviour, life-history) remain largely unknown in this context. In a common garden setup, we conducted an extensive examination of phenotypic traits suspected to be involved in the divergence of two recently evolved morphs of Arctic charr (Salvelinus alpinus), and investigated the consequences of potential patterns of trait covariance on the phenotype of their hybrids. We observed differences among morphs in overall phenotypic variance and in trait correlations. Phenotypic contrainsts also tended to be reduced in the hybrids, which corroborates the narrative of hybridization facilitating adaptive divergence by relaxing trait covariance. However, the hybrids were associated with reduced phenotypic variance at different scales (i.e. at the scale of the entire P matrix and in different parts of the multivariate space), and we identified stronger correlations between several ontogenetic and morphological traits in the hybrids than in both morphs. These findings suggest a limited potential for hybridization to generate phenotypic novelty, and emphasise the need for multivariate approaches conciliating ontogenetic, morphological and behavioural processes to study the processes of adaptive divergence and speciation.

evolutionary biology↗

bioRxiv2020

Animal personality adds complexity to the processes of adaptive divergence and speciation.

Divergent selection is a powerful driver of speciation and has been widely studied in relation to the physical characters of organisms. Because evolution of behavioural traits may contribute to evolutionary processes, we explored how consistent variation in behaviours may affect the process of adaptive divergence and speciation. We studied whether two sympatric morphs of Arctic charr (Salvelinus alpinus) have recently evolved genetically-based differences in personality that conform to their respective ecological niches, and whether these differences contribute to reproductive isolation by generating maladaptive hybrid behaviours. Studying three aspects of behavioural variation (average trait value, consistent individual differences and trait covariance), we assessed the sociality and risk-taking propensity of hybrid and pure-morph offspring reared in common conditions. Contrary to expectations, the two morphs did not differ in the average values of these traits but showed different behavioural syndromes (trait covariances). While the hybrids did not differ from either morph in their average behavioural responses, they showed less individual consistency in these behaviours and a different set of behavioural syndromes. Differences between morphs and their hybrids in other behavioural aspects than their average behavioural responses suggest that our understanding of speciation processes can benefit from an integrative view of behavioural variation.

evolutionary biology↗