Size differences among canaries, goldfinches and allies may explain correlated evolution of song and colour.

Sexual signals such as colour ornamentation and birdsong evolve independently of each other in some clades, and in others they evolve positively or negatively correlated. We rarely know why correlated evolution does or does not occur. Here, we show positively correlated evolution between plumage colour and song motor performance among canaries, goldfinches and allies, associated with species differences in body size. When controlling for body size, the pattern of correlated evolution between song performance and colour disappeared. Syllable diversity was not as strongly associated with size, and did not evolve in a correlated manner with colour. We argue that correlated evolution between song and colour was mediated by large size limiting song motor performance, likely due to constraints on the speed of moving heavier bills, and by larger species having less saturated plumage colour, possibly due to life-history traits of larger birds (e.g. longevity, stable pairs) contributing to weaker sexual selection. Results are consistent with the hypothesis that correlated evolution between sexual signals is influenced by how, in a clade, selective pressures and constraints affecting each type of signal happen to be co-distributed across species. Such contingency helps explain the diversity in clade-specific patterns of correlated evolution between sexual signals.

Molecular data reveal multiple lineages of Scinax nebulosus (Spix, 1824) (Anura: Hylidae) with Plio-Pleistocene diversification in different Brazilian regions.

To understand the organism's history, we can start assessing the complexity of the biome where they occur. In this study, we used a region of the mitochondrial genome, the rRNA 16S, to evaluate the genetic differentiation in Scinax nebulosus along with its geographical range highlighting important Brazilian biomes as Restinga, Cerrado, Amazon, and Atlantic Forest. Geographically structured genetic divergence was observed within the species S. nebulosus. The values of the fixation index (Фst) and the pairwise Fst index were high and significant regarding this structuring. Besides, the haplotype network corroborates these results with the haplotypes arrangement found by separating the S. nebulosus populations in two major groups: North and Northeast. The lineage delimitation analyses indicate the occurrence of several lineages with divergence mainly between the samples from the Northeast group. Thus, we can suggest that S. nebulosus may present itself as a group of cryptic species due to the genetic characteristics found. The existence of a mosaic of heterogeneous habitats may explain the genetic divergence found, which justifies the existence of cryptic species in this group. However, this hypothesis needs more detail in molecular studies, including large sample sizes and other population and demographic analyses.

Late-Onset Masseteric Metastasis of Malignant Melanoma in a Patient With Neurofibromatosis and Lipomatosis: A Diagnostic Challenge and Case Report.

Melanoma and neurofibromatosis (NF) are distinctly separate conditions, each characterized by unique pathophysiological processes. Nevertheless, their clinical presentations can share overlapping similarities. This report highlights a unique case involving a 68-year-old male with NF1 and lipomatosis, whose unwavering belief that a developing mass in the masseter region was benign and linked to the pre-existing diagnoses contributed to a significant delay in seeking healthcare. Consequently, this postponement resulted in the late diagnosis of disseminated malignant melanoma (stage IV, T4N0M1c). Given the patient's prognosis and poor general health, a palliative treatment plan was devised, entailing the complete excision of the masseteric mass and vertebral radiotherapy. Following a rapid and extensive progression of the cancerous lesions, the patient passed away in a palliative care infirmary four months after surgery. The significance of this case, justified not only by its uncommon presentation and atypical differential diagnosis, highlights the critical necessity of regular follow-up protocols for melanoma patients, particularly those prone to metastasis, while ensuring patient attendance. Furthermore, it underscores the necessity of patient education, particularly in recognizing early signs and symptoms, and timely intervention in cases with complex comorbidities.

Independent evolution of song diversity and song motor performance in canaries, goldfinches and allies indicates clade-specific trade-offs in birdsong.

The diversity and the motor performance of birdsongs can both be sexually selected. In wood warblers, most species with high motor performance sing a greater proportion of trills, presumably to advertise performance, and thus have lower syllable diversity. We tested if this trade-off between motor performance and syllable diversity extends to canaries, goldfinches and allies, a clade with much longer and more varied songs. We assembled a molecular phylogeny and inferred song motor performance based on the speed of frequency modulation either in trills or in within-song intervals. The two metrics of performance were positively, but only mildly, related across species. While performance evaluated in intervals had high phylogenetic signal, performance evaluated in trills changed independently of phylogeny and was constrained by body size. Species in densely vegetated habitats sang fewer trills, but did not differ in motor performance. Contrary to wood warblers, song motor performance did not predict the proportion of trilled syllables nor within-song syllable diversity, perhaps because large differences in the song duration of canaries, goldfinches and allies prevent trills from severely compromising syllable diversity. Opposed results in wood warblers and in these finches indicate the existence of clade-specific trade-offs in the evolution of birdsong.