Biology subjects

Pfennig, D. W.

Publications and source records attributed to Pfennig, D. W..

3 recordsLinked to original sources

bioRxiv2025

Consequences of cannibalism: induced defense and kin discrimination in a rotifer

Resource polyphenisms result in the production of environmentally induced morphs with differential niche use. These striking examples of phenotypic plasticity are taxonomically widespread and ecologically important. However, cannibalism is a frequent repercussion of resource polyphenisms. Despite some benefits, cannibalism is always costly to victims and sometimes costly to the cannibal. Therefore, we here evaluate how morphological and behavioral plastic strategies to minimize these costs may evolve. To better understand the evolution and consequences of cannibalistic polyphenisms, we tested whether rotifers Asplanchna brightwellii possess effective morphological defenses against cannibalism and the ability to discriminate by genetic relationship. We found that small humps produced by vulnerable A. brightwellii limit cannibalism. We also found that cannibals were less likely to attack clonemates than non-kin. The rotifer genus Asplanchna comprises species with varying degrees of resource polyphenism, cannibalism, induced morphological defenses, and behavioral kin discrimination. The observed induced defense and kin discrimination in Asplanchna brightwellii likely represent evolutionary intermediates facilitating the evolution of a unique trimorphic resource polyphenism in congeners.

evolutionary biology↗

bioRxiv2025

Plasticity promotes persistence across novel environments in experimental microcosms

Phenotypic plasticity--the ability of organisms to adjust their traits in response to changes in their environment--has long been thought to prevent extinction in novel or changing environments. However, there are few tests linking plasticity to population persistence. Here, we show that plasticity promotes population persistence in replicate populations of rotifers. We experimentally exposed 33 clonal lines that varied in plasticity to over 20 novel environments for up to 40 overlapping generations. We found that clonal populations expressing plasticity in morphology and life history traits persisted longer and were less likely to go extinct in novel environments than populations not expressing such plasticity. These results directly link plasticity to population persistence in novel environments and suggest that plasticity can buy time for organisms in a changing world. TeaserA multigenerational experiment finds that environmentally induced traits allow populations to persist in novel environments.

ecology↗

bioRxiv2024

The Amphibian Genomics Consortium: advancing genomic and genetic resources for amphibian research and conservation

Amphibians represent a diverse group of tetrapods, marked by deep divergence times between their three systematic orders and families. Studying amphibian biology through the genomics lens increases our understanding of the features of this animal class and that of other terrestrial vertebrates. The need for amphibian genomic resources is more urgent than ever due to the increasing threats to this group. Amphibians are one of the most imperiled taxonomic groups, with approximately 41% of species threatened with extinction due to habitat loss, changes in land use patterns, disease, climate change, and their synergistic effects. Amphibian genomic resources have provided a better understanding of ontogenetic diversity, tissue regeneration, diverse life history and reproductive modes, anti-predator strategies, and resilience and adaptive responses. They also serve as essential models for studying broad genomic traits, such as evolutionary genome expansions and contractions, as they exhibit the widest range of genome sizes among all animal taxa and possess multiple mechanisms of genetic sex determination. Despite these features, genome sequencing of amphibians has significantly lagged behind that of other vertebrates, primarily due to the challenges of assembling their large, repeat-rich genomes and the relative lack of societal support. The emergence of long-read sequencing technologies, combined with advanced molecular and computational techniques that improve scaffolding and reduce computational workloads, is now making it possible to address some of these challenges. To promote and accelerate the production and use of amphibian genomics research through international coordination and collaboration, we launched the Amphibian Genomics Consortium (AGC, https://mvs.unimelb.edu.au/amphibian-genomics-consortium) in early 2023. This burgeoning community already has more than 282 members from 41 countries. The AGC aims to leverage the diverse capabilities of its members to advance genomic resources for amphibians and bridge the implementation gap between biologists, bioinformaticians, and conservation practitioners. Here we evaluate the state of the field of amphibian genomics, highlight previous studies, present challenges to overcome, and call on the research and conservation communities to unite as part of the AGC to enable amphibian genomics research to "leap" to the next level.

genomics↗