Biology subjects

Boudinot, B.

Publications and source records attributed to Boudinot, B..

2 recordsLinked to original sources

bioRxiv2025

Claws that snap: the raptorial mechanism of dryinid wasps

Prey capture is a key selection pressure, often favoring extreme performance morphologies. Many mechanisms of prey capture, however, remain poorly understood. In this study, we document the remarkable raptorial behavior and evolutionary biomechanics of the "pincer wasps" (Hymenoptera: Dryinidae). Dryinid claws, previously thought to function as simple vises (Nachtigall-&-Nachtigall-1974), are shown to possess "snap traps", or claws that close rapidly upon prey contact. Detailed morphological analysis, using synchrotron-radiation microtomography (SR-{micro}-CT), reveals that all long-clawed dryinids can overcenter their specialized anterior pretarsal claws, presumably allowing elastic energy storage in the pretarsal apodemes. Uniquely, explosive release of this energy, leading to claw closure, appears to occur not through active withdrawal of a latch, but as the direct consequence of contact with the prey: impact hyperextends a specialized trigger-joint complex of the tarsus, pulling the claw back into undercenter alignment, and so freeing the stretched apodeme to fully recoil. Such a "contact trigger" is eminently useful, as these trap-claw wasps prey on insects with explosive jump capacity; by linking trap shutting with prey contact, success chances are increased. Paleontological and allometric analyses suggest that the raptorial behavior likely preceded the evolution of overcentering, which appears to have evolved via release from developmental constraint on anteroposterior symmetry, leading to a distinct scaling rule. These findings expand the documented diversity of spring-loaded biological mechanisms and establish Dryinidae as a promising system for studying how developmental constraints, mechanical demands, and functional innovation shape ecomorphological diversity. HIGHLIGHTSO_LIDryinidae catch prey with spring-loaded trap claws, relying on a unique direct-action trigger. C_LIO_LIRaptorial behavior evolved first, followed by the functional derivation of two separate components. C_LIO_LIThe evolution of novel raptorial mechanism was enabled by release of ancestral developmental constraint. C_LI

evolutionary biology↗

bioRxiv2024

Inferring a role for programmed cell death during the origin and evolution of wing polyphenism in ants

Major evolutionary transitions in individuality occur when solitary individuals unite to form a single replicating organism with a division of labor between constituent individuals. Key examples include the evolution of multicellularity, eusociality, and obligate endosymbiosis. Programmed Cell Death (PCD) has been proposed to play an important role during major transitions to multicellularity, yet it remains unclear to what extent PCD plays a role in other major transitions. Here we test if PCD was involved in the major transition to eusociality in ants, where solitary individuals united to form eusocial colonies with a division of labor between a winged queen caste and a wingless worker caste. The development of wings in queens but not in workers in response to environmental cues is called wing polyphenism, which evolved once and is a general feature of ants. Both wing polyphenism and eusociality evolved at the same time during the origin of ants and were likely intimately linked--the suppression of wings in workers may have reduced their ability to participate in mating flights thereby reinforcing the reproductive division of labor within the parental nest. We therefore tested whether PCD plays a role in the degeneration of wings during development of the worker caste across the ant phylogeny encompassing species with both ancestral-like and derived characteristics. We show that PCD, mediated by the apoptosis pathway, is present in the degenerating wing primordia of worker larvae in 15 out of the 16 species tested. Using ancestral state reconstruction, we infer a role for PCD in regulating wing polyphenism in the last common ancestor of all extant ants. Our findings provide evidence that a degenerative mechanism (PCD) plays a role in the origin of wing polyphenism, and therefore, in facilitating the major transition to eusociality in ants. PCD may generally play a key role in the evolution of biological complexity by facilitating major transitions at different scales, such as multicellularity and eusociality.

evolutionary biology↗