Biology subjects

Picq, S.

Publications and source records attributed to Picq, S..

4 recordsLinked to original sources

bioRxiv2026

Foraging behavior, not prey identity, facilitates niche packing in a tropical montane avifauna

Understanding the mechanisms of key ecological and evolutionary patterns and the restructuring of biodiversity in the Anthropocene is contingent on filling knowledge gaps about resource consumption across trophic levels and how resource use is limited by factors intrinsic to organisms and extrinsic aspects of the environment across deep and shallow timespans. We quantified diet composition and foraging behavior across a community of invertivorous birds in the Ecuadorian Andes to explore how resource use facilitates the packing and expansion of niche space across an elevational gradient, contributing the tropical Andes status as the most species-rich region on earth. We found evidence that niche packing of morphologically similar species may be offset by greater behavioral plasticity in foraging behavior at species-rich lower elevations where competition is likely more intense and invertebrate prey more diverse. We also tested the extent to which the breadth and similarity of birds foraging and dietary niches are shaped by the environmental and competitive gradient across elevation versus species identity and phylogenetic similarity. The specific behaviors and substrates that birds used were far more strongly associated with species identity than elevation, particularly for behaviors requiring specialized morphology that is phylogenetically conserved. In contrast, species identity had little effect on prey selection, which was more strongly associated with elevation. Our findings suggest that elevational range dynamics and niche packing of tropical montane birds are more strongly shaped by phylogenetic constraints on foraging behavior than by specializing on specific prey taxa, highlighting the importance of maintaining structural integrity in tropical forests for preserving functional diversity.

ecology↗

bioRxiv2026

Electric signal polymorphism predicts dietary niche partitioning in a weakly electric fish

Electric organ discharge (EOD) waveform diversity in African elephantfish is often attributed to sexual selection, yet EODs also mediate active electrolocation during prey detection, raising the possibility that natural selection on foraging ecology contributes to waveform divergence. Paramormyrops kingsleyae exhibits an intraspecific polymorphism where certain populations emit biphasic EODs whereas other populations emit triphasic waveforms. The genes underlying this polymorphism show signatures of selection; the polymorphism persists despite gene flow and is behaviorally discriminable by the fish themselves. If waveform differences influence prey detection during active electrolocation, biphasic and triphasic fish should consume systematically different prey. We tested this prediction using DNA metabarcoding of gut contents from 186 mormyrids representing 16 species across eight sites in Gabon, employing two independent COI primer sets for cross-validation and pairing dietary data with environmental invertebrate sampling to distinguish active prey preference from passive availability. At the community level in the diverse Bale Creek mormyrid assemblage, species identity was the dominant predictor of diet composition (R{superscript 2} {approx} 24%), consistent with phylogenetic signal in foraging ecology. Within P. kingsleyae, waveform type was the strongest independent predictor of dietary composition (R{superscript 2} = 5-6%), explaining variance independently of geographic region, sex, body size, and parasitism status -- a result concordant across both primer sets. Dietary differences were driven by prey species turnover rather than differential abundance of shared prey, and prey selectivity analyses confirmed that waveform types differ in which prey they actively prefer, not merely in what is locally available. These findings are consistent with natural selection on foraging ecology contributing to the maintenance of EOD waveform polymorphism, though the sensory mechanisms linking subtle waveform differences to prey detection remain an open question.

ecology↗

bioRxiv2026

The Genomic Basis of Electric Signal Diversity

Behavioral diversity is a striking result of species diversity, shaped by intertwined mechanisms, developmental pathways, and evolutionary histories. Yet the genetic underpinnings of behavioral evolution remain obscure, even though they are key to understanding how organisms adapt and diversify. Weakly electric African elephantfishes provide a rare opportunity to dissect the genetics of behavior because their electric communication signals are quantifiable, stereotyped, and directly tied to identifiable cellular mechanisms. Among elephantfishes, electric organ discharges (EODs) vary widely across species and populations, shaping mate choice, social interactions, and reproductive isolation. A key axis of this diversity is the presence or absence of an initial phase in the EOD waveform--a discrete, repeated evolutionary transition whose genetic basis has remained unresolved. Here we show, using whole-genome resequencing, population-genomic analyses, transcriptomics, and histology from 306 specimens, that biphasic EODs in Paramormyrops kingsleyae have evolved repeatedly through independent de novo regulatory mutations at distinct genomic loci. These population-specific mutations occur exclusively in noncoding regions, show localized signatures of selection, and are associated with differences in gene expression and protein localization in the electric organ, indicating that they act through cis-regulatory mechanisms affecting electrocyte development. These findings challenge the expectation that repeated within-species adaptations primarily draw from standing ancestral variation, revealing instead that the developmental program underlying electric signaling contains multiple points of regulatory sensitivity. Distinct genetic changes can therefore produce the same behavioral phenotype, enabling repeated evolutionary transitions even within a single species. More broadly, our results show how developmental architecture shapes the evolutionary pathways available to behavior, helping explain why communication signals in elephantfishes--and in other radiations--diversify so rapidly.

evolutionary biology↗

bioRxiv2019

Berry and pip form covariation in wild and domesticated grapevines: eco-evo-devo implications and archaeobotanical perspectives

The phenotypic changes that occurred during the domestication and diversification of grapevine are well known, particularly changes in seed morphology, but the functional causes and consequences behind these variations are poorly understood. Wild and domesticate grapes differ, among others, in the form of their pips: wild grapes produce roundish pips with short stalks and cultivated varieties have more elongated pips with longer stalks. Such variations of form are of first importance for archaeobotany since the pip form is, most often, the only remaining information in archaeological settings. This study aims to enlight archaeobotanical record and grapevine pip development by better understanding how size and shape (co)variates between pip and berry in both wild and domesticated Vitis vinifera. The covariation of berry size, number of seeds per berry ("piposity"), pip size and pip shape were explored on 49 grapevine accessions sampled among Euro-Mediterranean traditional cultivars and wild grapevines. We show that for wild grapevine, the higher the piposity, the bigger the berry and the more elongated the pip. For both wild and domesticated grapevine, the longer is the pip, the more it has a "domesticated" shape. Consequences for archaeobotanical studies are tested and discussed, and these covariations allowed the inference of berry dimensions from archaeological pips from a Southern France Roman site. This systematic exploration sheds light on new aspects of pip-berry relationship, in both size and shape, on grapevine eco-evo-devo changes during domestication, and invites to explore further the functional ecology of grapevine pip and berry and notably the impact of cultivation practices and human selection on grapevine morphology.

plant biology↗