Biology subjects

Lopes, R. J.

Publications and source records attributed to Lopes, R. J..

3 recordsLinked to original sources

bioRxiv2026

ARTIFICIAL SELECTION DIVERSIFIES BIRDSONG THROUGH POLYGENIC CHANGES ACROSS SENSORY AND MOTOR SYSTEMS

Vocal learning, or the ability to acquire and produce contextualized sounds through social interaction, underlies human speech yet has evolved in a few animal lineages, including songbirds. In songbirds, learned song is produced by a dedicated neural circuit and depends on auditory feedback for its acquisition and maintenance. Roughly four centuries of artificial selection on the domestic canary (Serinus canaria) have produced song breeds whose vocalizations diverge as much as those of distinct species, offering a rare intraspecific system in which to identify the genetic and neural changes underlying vocal divergence. Here we show that selection for song reshaped the canary song control system. Compared with breeds selected for plumage or body form, song breeds show increased neural progenitor proliferation and breed-specific changes in neuronal recruitment, sensorimotor brain region volume, and auditory sensitivity. Genome-wide analyses reveal a polygenic architecture underlying song divergence, enriched for transcriptional regulation and synaptic transmission genes. Among these, we find a coding variant in ADGRV1, the gene mutated in human Usher syndrome type 2C, associated with low-frequency singing and elevated auditory thresholds in canary. Disrupting ADGRV1 in zebrafish alters hair cell dynamics, linking adgrv1 mutation to a peripheral sensory mechanism. These findings demonstrate that learned vocal behavior can diversify rapidly through changes spanning sensory, neurogenic, and motor systems, with hearing itself as a substrate for selection.

evolutionary biology↗

bioRxiv2026

Predation and the Evolution of Island Bird Plumage Colouration: Experimental Insights from Island and Mainland Environments

Islands serve as natural laboratories for exploring evolutionary processes, often fostering unique species through their isolation and distinct ecological conditions. These environments present opportunities to study how a range of selective pressures shape biodiversity. Bird plumage colouration is one trait that has shown to consistently change in island populations, and predation has been hypothesized to influence these differences. While animals often face a trade-off between signalling to conspecifics and avoiding detection by predators, the role of predation in shaping conspicuousness remains underexplored experimentally. In this study, we asked how predation pressure differs between insular and mainland habitats, and whether predation risk covaries with conspicuousness of male and female birds across environments. In a field experiment, we investigated predation rates using 3D-printed models painted to represent both sexes of 12 bird species from three archipelagos (Madeira, Azores, and Canary Islands) and their closest mainland relatives. These models were deployed in the species natural environments to measure hit rates (a proxy for predation risk), accounting for factors that influence prey detectability, such as colour of the models, background contrast, and vegetation. We found that models on the islands experienced less hits compared to those on the mainland, while sexual dichromatic models were more likely to be dislodged on the mainland. In addition, for mainland sites, increased chromatic contrast correlated with a higher probability of dislodgment, suggesting that more conspicuous models were more likely to be hit. These results highlight that while predation constrains conspicuousness, other ecological and evolutionary factors likely drive the reduced plumage colouration observed in island birds. Our research offers experimental insights into how predation interacts with conspicuous traits in shaping plumage colouration in birds.

evolutionary biology↗

bioRxiv2019

Genetic Basis Of De Novo Appearance Of Carotenoid Ornamentation In Bare-Parts Of Canaries

AO_SCPCAPBSTRACTC_SCPCAPUnlike wild and domestic canaries (Serinus canaria), or any of the three dozen species of finches in genus Serinus, the domestic urucum breed of canaries exhibits bright red bills and legs. This novel bare-part coloration offers a unique opportunity to understand how leg and bill coloration evolve in birds. To identify the causative locus, we resequenced the genome of urucum canaries and performed a range of analyses to search for genotype-to-phenotype associations across the genome. We identified a nonsynonymous mutation in the gene BCO2 (beta-carotene oxygenase 2, also known as BCDO2), an enzyme involved in the cleavage and breakdown of full-length carotenoids into short apocarotenoids. Protein structural models and in vitro functional assays indicate that the urucum mutation abrogates the carotenoid cleavage activity of BCO2. Consistent with the predicted loss of carotenoid cleavage activity, urucum canaries had increased levels of full-length carotenoid pigments in bill tissue and a significant reduction in levels of carotenoid cleavage products (apocarotenoids) in retinal tissue compared to other breeds of canaries. We hypothesize that carotenoid-based bare-part coloration might be readily gained, modified, or lost through simple switches in the enzymatic activity or regulation of BCO2 and this gene may be an important mediator in the evolution of bare-part coloration among bird species.

evolutionary biology↗