Biology subjects

Bellvert, A.

Publications and source records attributed to Bellvert, A..

2 recordsLinked to original sources

bioRxiv2024

Tempo and mode of diversification of the red devil spiders (Araneae: Dysderidae) of the Canary Islands

The study of adaptive radiations has shed light on our current understanding of evolution. However, previous studies examining the mode in which species diversified, how diversification rates varied, and how ecological specialization affected these processes have found few different results across different taxa and geographic and ecological systems, showing how complex this process is. To gain a more complete picture of how species evolve, additional model systems that encompass alternative ecological requirements are needed. Here, we present the results of a study aimed to unravel the diversification mode and evolutionary drivers of the spider genus Dysdera, the red devil spiders, endemic to the Canary Islands. These species exhibit remarkable phenotypic variability in their mouthparts, which has been related to different levels of specialization in the predation of isopods. We explored patterns of linage diversification and assessed the role of trophic specialization as a driver of species diversification. Additionally, we used climatic variables, occurrence data and morphological information to unravel the underlying mode of speciation by means of joint species distribution models and age-range correlation methods. Our results reveal that red devil spiders underwent an early burst of diversification, followed by a slowdown of diversification rates, which is a hallmark of adaptive radiation. We also found evidence that the trophic morphology shaped diversification, with specialist species exhibiting higher rates of diversification. Finally, our analyses suggest that speciation occurred mostly in allopatry, with subsequent secondary sympatry following range expansion.

evolutionary biology↗

bioRxiv2021

Reticulate Evolutionary History in a Recent Radiation of Montane Grasshoppers Revealed by Genomic Data

Inferring the ecological and evolutionary processes underlying lineage and phenotypic diversification is of paramount importance to shed light on the origin of contemporary patterns of biological diversity. However, reconstructing phylogenetic relationships in recent evolutionary radiations represents a major challenge due to the frequent co-occurrence of incomplete lineage sorting and introgression. In this study, we combined high throughput sequence data (ddRADseq), geometric morphometric information, and novel phylogenetic inference methods that explicitly account for gene flow to infer the evolutionary relationships and the timing and mode of diversification in a complex of Ibero-Maghrebian montane grasshoppers of the subgenus Dreuxius (genus Omocestus). Our analyses supported the phenotypic distinctiveness of most sister taxa, two events of historical introgression involving lineages at different stages of the diversification continuum, and the recent Pleistocene origin (< 1 Ma) of the complex. Phylogenetic analyses did not recover the reciprocal monophyly of taxa from Iberia and northwestern Africa, supporting overseas migration between the two continents during the Pleistocene. Collectively, these results indicate that periods of isolation and secondary contact linked to Pleistocene glacial cycles likely contributed to both allopatric speciation and post divergence gene flow in the complex. This study exemplifies how the integration of multiple lines of evidence can help to reconstruct complex histories of reticulated evolution and highlights the important role of Quaternary climatic oscillations as a diversification engine in the Ibero-Maghrebian biodiversity hotspot.

evolutionary biology↗