Biology subjects

Martin-Eberhardt, S.

Publications and source records attributed to Martin-Eberhardt, S..

3 recordsLinked to original sources

bioRxiv2026

Shedding light on fenestrations in carnivorous pitcher plants: a test for convergent function

A longstanding question in evolution is if similar morphologies shared by distantly related organisms facing similar environmental pressures belie similar functions. The carnivorous pitcher form has evolved in three distinct plant lineages and encompasses a suite of convergent morphological traits, providing a natural experiment to test hypothesized links between morphology and function. Multiple pitcher plant species possess fenestrations (i.e., small windows) that let light pass through the pitcher leaf. While research on one species, Nepenthes aristolochioides, demonstrates that fenestrations manipulate light to create false exits and increase prey capture, whether this convergent morphology serves this convergent function in other pitcher species remains unresolved. We explored the function of fenestrations in two additional species of pitcher plants, Nepenthes klossii and Cephalotus follicularis, where the morphology and function of fenestration were previously unexplored. We inspected micromorphology of pitcher structure, conducted an insect bioassay with live plants to test for links between morphology and function, and quantified traits associated with light manipulation from herbarium specimens. Both species exhibited fenestration and related pitcher morphology similar to N. aristolochioides. Yet our experiments did not reveal a significant effect of light passing through fenestrations on fly capture for these two species. Key differences between these species and the previously investigated species may be the presence of wax crystals and the absence of viscoelastic fluid. While future studies may uncover weak to moderate light manipulation function not detected in our study, our data do not support convergent function in these distantly related, morphologically similar species.

evolutionary biology↗

bioRxiv2026

Convergent evolution of red pigmentation in extrafloral nectaries: global patterns and mechanisms

Convergent traits are a signature of adaptation, where shared selective pressures may lead to the replicated evolution of traits with similar function. Here, we present an integrative investigation of a widespread yet understudied feature of an iconic, convergent mutualistic plant trait - red pigmentation in extrafloral nectaries (EFNs). We surveyed 625 species to describe the distribution of red coloration in EFNs across plant morphology, biogeography, and phylogeny for the first time and propose several adaptive hypotheses for the drivers of their convergence across plants. We then test several of these hypotheses by integrating our global-scale biogeographic and phylogenetic analysis with phylogenetically paired common garden bioassays and a museum collections survey. We find that across the plant phylogeny, cold wet regions and deserts are hotspots of red EFN coloration, and multiple lines of evidence point to a fungal defense role of red pigments in EFNs. Ultimately, our findings highlight red EFNs as a highly convergent phenotype across plants and point to distinct selective pressures underlying the distribution of EFN coloration and EFNs themselves.

evolutionary biology↗

bioRxiv2026

Nonlinear Impacts of Herbivory on Plants Explain the Herbivory Paradox

Herbivores strongly shape plant ecology and evolution. Yet plants typically sustain low, tolerable levels of damage, raising the question of how herbivory influences plant biology despite often weak fitness effects. Analyzing 1,145 datasets of the effects of damage on fitness for 103 plant species worldwide, we show that nonlinear tolerance to damage is one explanation for this paradoxical contradiction. Plants are tolerant of low levels of damage, but infrequent, severe damage levels disproportionately reduce plant fitness. Models incorporating nonlinear tolerance suggest that disproportionate tolerance to low levels of damage stabilizes population dynamics and promotes coevolutionary feedback with herbivores. Pervasive nonlinear tolerance shows consistent patterns across environmental gradients, may alter the stability of food webs, and may explain why herbivory matters despite the world being green.

ecology↗