About

Patrick Rohner is an Assistant Professor who studies how developing organisms respond to changing environments and how developmental plasticity, once established, affects evolution on different time scales. His research primarily uses dung beetles and black scavenger flies as model systems, although he works with various invertebrates. Originally from Switzerland, he speaks German (specifically Swiss German) and some French. Outside of his professional work, he enjoys hiking, baking, and listening to progressive house music.

Research topics

• Biology
• Evolutionary biology
• Ecology
• Neuroscience
• Genetics
• Zoology

Selected publications

• Diet Outweighs Vertical Transmission in Shaping Dung Beetle Larval Gut Microbiomes

  Molecular Ecology · 2026-04-01 · 1 citations

  articleOpen accessSenior author

  The microbiome is central to host development and adaptation, yet the balance between vertical and environmental acquisition, and how hosts shape surrounding microbial communities, remains poorly understood. Dung beetles rely on microbial symbionts to extract nutrients from vertebrate dung, with part of their microbiome vertically inherited via a maternal faecal pellet. However, the relative importance of vertical versus horizontal transmission is unclear. We examined this in the gazelle dung beetle (Digitonthophagus gazella), rearing larvae on brood balls made of dung from grass-(high-quality), hay-(low-quality) or silage-fed (a novel fermentable energy-rich diet) cattle, with or without maternal microbes. We integrated measures of gut morphology with 16S rRNA amplicon sequencing to assess host development and the gut microbiome. Diet significantly influenced overall size, hindgut area, and microbiome composition. Silage-dung fed larvae had more even and taxonomically rich microbiomes, with higher microbial diversity in individuals reared with maternal microbes. Diet explained ~26% of the variation in microbial composition, while the vertical transmission of microbes only explained 3%. Vertical transmission only slightly increases microbial species richness and relative hindgut area but did not influence overall microbial diversity. The larval brood ball contributed 40%-50% of the hindgut microbiome, while maternal microbes contributed < 0.05%. These findings demonstrate that horizontal acquisition through diet is the dominant force shaping larval gut microbiomes, while vertical inheritance plays a minor but detectable role in enhancing richness and gut development. More broadly, this work reinforces the importance of examining host-microbiome-environment interactions in ecological and evolutionary contexts.

  PublisherDOI

• Cryptic genetic variation revealed by diet uncovers a trade-off between growth and telomere length

  Evolution · 2026-03-11 · 2 citations

  article

  Evolutionary theory predicts that variation in longevity persists due to trade-offs between early-life fitness traits (e.g., growth or fecundity) and long-term somatic maintenance. However, such trade-offs can be difficult to detect and may often become apparent only under certain conditions. For instance, developing in novel or atypical environments may alter the genetic architecture of traits, revealing trade-offs that are otherwise hidden under normal conditions. To test this, we compared full-sibling families of the Mexican spadefoot (Spea multiplicata) reared across two larval diets: a typical detritus diet and an atypical live shrimp diet, which they are competitively excluded from in nature. The shrimp diet significantly increased broad-sense genetic variance and heritability for larval growth rate, whereas heritability for post-metamorphic telomere length - a known longevity correlate - remained similar across diets. Moreover, only on the shrimp diet did families with faster growth exhibit shorter telomeres, consistent with a diet-dependent trade-off between growth and somatic maintenance. Overall, our study shows that developing under atypical dietary conditions exposes previously cryptic genetic variation in growth, thereby revealing a trade-off with somatic maintenance. These findings have implications for understanding how environmental change, such as rapid dietary shifts, can shape aging processes and vulnerability to age-related disease.

  PublisherDOI

• A review on true dung beetles' evolutionary and ecological responses to temperature and impacts on ecosystem functions

  Ecological Entomology · 2026-04-05

  articleOpen accessSenior authorCorresponding

  Abstract Changing climates present organisms with novel selective pressures, with consequences for both biodiversity and ecosystem functioning. Organisms may respond to all of these challenges through range shifts, rapid evolution, phenotypic plasticity or a combination of strategies. The true dung beetles (Scarabaeidae: Scarabaeinae) have emerged as a valuable system for studying these responses and their interactions. With more than 6990 described species worldwide, they play critical roles as ecosystem engineers, particularly in agricultural systems where they contribute to dung decomposition, nutrient cycling and pest control. However, the ecological and economic benefits they provide are increasingly threatened by environmental change. In this review, we synthesize the literature on dung beetle responses to variation in temperature across ecological and evolutionary timescales. We discuss their evolutionary history, the role of temperature in shaping developmentally plastic and evolutionary responses, evidence for climatic divergence and range shifts and the implications for ecosystem functioning. Overall, there is strong evidence for thermal plasticity in life history, behaviour and morphology. There is also a growing number of studies demonstrating evolutionary divergence on relatively short timescales. Elevational and geographic range shifts have also been reported but remain poorly documented. Key knowledge gaps include (i) limited understanding of the evolvability of complete thermal performance curves, which constrains evolutionary predictions, (ii) insufficient knowledge about how plastic and evolutionary responses scale up to affect ecosystem functioning in complex agricultural environments and (iii) the largely unexplored role of symbionts in dung beetle ecology and evolution. We outline research priorities that address fundamental questions in ecology and evolution while also informing the conservation of dung beetle diversity and the ecosystem services they provide in both agricultural and natural systems.

  PublisherDOI

• Faunistic data of Sepsidae (Diptera) from Switzerland and additional countries including the first Swiss record of Meroplius fukuharai (Iwasa, 1984)

  The Catalogue of Life · 2026-02-17

  datasetOpen access1st authorCorresponding
  PublisherDOI

• Faunistic data of Sepsidae (Diptera) from Switzerland and additional countries including the first Swiss record of Meroplius fukuharai (Iwasa, 1984)

  The Catalogue of Life · 2026-02-16

  datasetOpen access1st authorCorresponding
  PublisherDOI

• Environmental modifications of dung beetle larvae shape their growth and life history

  Journal of Experimental Biology · 2025-07-25 · 1 citations

  articleOpen accessSenior author

  Organisms are not just passive recipients of environmental pressures but can shape the environment they experience. Yet, the mechanisms and evolutionary implications of such niche construction remain poorly understood. Here, we studied these effects in the gazelle dung beetle (Digitonthophagus gazella). Larvae of this species develop in an underground brood chamber (a 'brood ball') composed of dung, which serves as the sole source of food for a single larva. Throughout its development, the larva extensively modifies its environment by constantly eating, regurgitating and shaping particle sizes within the brood ball. Previous research suggests that these larval manipulations increase environmental quality and nutrient availability. However, how larval modifications affect larval growth and how these modifications differ between species remain poorly understood. We studied the impact of larval environmental modifications by transplanting eggs into previously modified or unmodified environments, whilst controlling for the confounding effect of maternally derived microbes. Additionally, we also studied how D. gazella larvae grow in an environment that was modified by a different species (Onthophagus binodis) to investigate species-specific differences of niche construction. Counter to expectations, we found that larval modifications by conspecifics did not confer a fitness benefit to D. gazella. However, surprisingly, individuals developing in a brood ball modified by a heterospecific individual emerged significantly quicker. These findings provide mixed support that environmental modifications by a larva enhance its growth. Our research adds to the growing literature on the complex interactions between organisms and their environment and how those interactions feed back on organismal development and performance.

  PublisherOA PDFDOI

• Author response for "Developmental lines of least resistance predict standing genetic covariation but do not constrain plasticity or rapid evolution"

  2025-04-17

  peer-review1st authorCorresponding
  PublisherDOI

• The impact of microplastic contamination in cow manure on reproductive behavior and larval survival in the dung beetle <i>Onthophagus taurus</i>

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-10-15

  preprintOpen accessSenior authorCorresponding

  Abstract Microplastics are an emerging environmental hazard on a global scale. Their detection in agricultural environments is of particular concern not only for food contamination, but also because microplastics negatively impact detritivores and their ecosystem functioning. Dung beetles in particular provide vital ecosystem services in agricultural environments and are often vulnerable to anthropogenic hazards, but whether they are affected by microplastics remains unclear. Here, we test whether artificial contamination of cow dung with thermoplastic polyurethane (TPU) has the potential to affect the juvenile development and maternal behavior of the bull-headed dung beetle Onthophagus taurus . Dung beetles exhibited high mortality when exposed to elevated concentrations of TPU. In addition, females were equally likely to provision offspring with TPU-spiked (and lethal) cow dung as with control dung, suggesting that females cannot differentiate between highly toxic microplastic-contaminated and uncontaminated cow dung. Our findings highlight potentially severe consequences for dung beetles if microplastics persist and accumulate, although the levels of exposure in the field are unknown. Although the direct environmental hazards and the mechanisms mediating the negative impacts of TPU microplastics remain to be assessed, this study suggests that microplastics may negatively impact dung beetles and their ecosystem services. Future work assessing exposure levels in the field as well as dung beetles’ potential to evolve resistance against microplastic pollution will be necessary to assess the long-term impact of microplastic presence on dung beetle ecosystem functioning.

  PublisherOA PDFDOI

• The external rumen of dung beetles: Complex interactions between larvae and their ontogenetic environments shape growth and life history

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-03-24

  preprintOpen accessSenior author

  Abstract Organisms are not just passive recipients of environmental pressures but are able to shape the environment they experience. However, the mechanisms and the evolutionary implications of such niche construction remains poorly understood. Larvae of the gazelle dung beetle ( Digitonthophagus gazella ) extensively modify their environment and benefit from microbial symbionts to digest their cellulose-rich diet. These modifications are so extensive that previous research suggests that dung beetle larvae establish an “external rumen”, where behavioral adaptations promote beneficial symbionts that enhance nutrient availability in the developmental environment. However, the mechanisms underlying these environmental modifications and their impact on species differences remains unclear. To investigate the external rumen hypothesis, we study the impact of larval environmental modifications on adult life-history traits in the dung beetle Digitonthophagus gazella . We did this by transplanting eggs into modified and unmodified environments, whilst excluding maternally derived microbes. Additionally, we include a heterospecific ( Onthophagus binodis) manipulated environment to investigate evolution of species-specific effects. Counter to expectations, we find larval modifications by conspecifics did not confer a benefit to D. gazella in any aspect measured. However, surprisingly, focals from heterospecific treatments emerged significantly quicker. Additionally, we highlight the primary condition of the developmental environment as an essential factor in determining fitness benefits compared to any additive environmental effects. Our research adds to the growing literature on organism by environment interactions and demonstrates the relationship between dung beetle larvae and their developmental environment are complex and are not consistent with the presence of a simple external rumen.

  PublisherOA PDFDOI

• Life history evolution of insects in response to climate variation: seasonal timing versus thermal physiology

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-02-07 · 6 citations

  preprintOpen accessSenior author

  Abstract Climate adaptation in insects can proceed via responses in life history traits and their thermal plasticity, and through phenological shifts mediated by responses to photoperiodic cues (“photoperiodism”). While, experimental studies demonstrate evolutionary potential for both modes of adaptation, it remains unclear how evolution will unfold in natural populations, limiting our ability to predict how insects will respond to climate change. Here we review the literature and perform an analysis of published studies revealing that photoperiodism for diapause induction evolves predictably along latitude, with high-latitude populations entering diapause earlier. In contrast, although a few species showed clinal variation in life history and thermal plasticity, the direction of these clines were not consistent across taxa. This suggests that while insect life history and physiological adaptation to temperature can evolve, phenological shifts via evolution of photoperiodism is likely to be a more common and predictable response to future climate change.

  PublisherDOI

Frequent coauthors

• Wolf U. Blanckenhorn

  University of Zurich

  30 shared

• Armin P. Moczek

  Indiana University Bloomington

  30 shared

• Martin A. Schäfer

  University of Zurich

  16 shared

• David Berger

  Duke University

  13 shared

• Nalini Puniamoorthy

  National University of Singapore

  12 shared

• Julian Baur

  Uppsala University

  11 shared

• Jeannine Roy

  University of Zurich

  11 shared

• Yonggang Hu

  Indiana University Bloomington

  10 shared

Labs

• Rohner LabPI

Education

• PhD, Department of Evolutionary Biology and Environmental Studies

  University of Zurich

  2018