Biology subjects

Lyberger, K.

Publications and source records attributed to Lyberger, K..

12 recordsLinked to original sources

bioRxiv2026

TPCdesign: A guide to designing informative thermal performance experiments

1. Thermal performance curves (TPCs) are widely used to quantify temperature dependence of biological traits, but estimating them requires experiments across multiple temperatures. Because these experiments can be costly, researchers must balance the number and placement of temperature treatments against replication within treatments. Evenly spaced temperatures are a common default, but may allocate effort inefficiently when thermal responses are nonlinear or strongly asymmetric. 2. We developed TPCdesign, an R package for planning temperature-trait experiments. TPCdesign uses a pseudo-Bayesian (robust) D-optimal experimental design to identify sets of temperatures expected to provide the most information about a TPC, while allowing users to incorporate prior knowledge of thermal limits and curve shape, uncertainty in that knowledge, available numbers of treatments, and practical restrictions on temperature spacing. 3. Using simulation-based worked examples, we show that optimized designs can recover TPCs more accurately than evenly spaced designs, particularly for asymmetric curves and when the number of available temperature treatments is modest. Optimization primarily improves resolution of regions where performance changes rapidly and can substantially improve estimation of upper thermal limits while retaining information across the rest of the curve. 4. TPCdesign provides a practical framework for allocating limited experimental resources according to the biological response researchers seek to estimate. Rather than prescribing a universal set of temperatures, it allows experimental designs to reflect existing biological knowledge, uncertainty, and logistical constraints, improving the information gained from costly thermal performance experiments.

ecology↗

bioRxiv2025

Microclimate habitats of Culex mosquitoes in urban desert environments

Culex mosquitoes are important vectors of West Nile virus, and, as small-bodied ectotherms, are sensitive to temperature. This is especially important for juvenile stages which are confined to the body of water where they hatched and are unable to relocate for thermoregulation. In an urban desert like Maricopa County, Arizona, the macroclimate is strongly influenced by the urban heat island effect where larval thermal maxima are frequently exceeded. Understanding the local temperatures (microclimates) of sites that mosquitoes chose for egg-laying and larval development is important for managing mosquito populations and reducing disease risk. We deployed small temperature loggers at multiple breeding sites throughout the city and compared those temperatures to gridded reanalysis macroclimate data. We found that the recorded aquatic microclimates were consistently cooler than corresponding macroclimates, and that higher canopy cover further buffered hot temperatures. This suggests that using interpolated macroclimate data to estimate mosquito population dynamics overestimates the thermal stress local mosquitoes actually experience. By using microclimate measures we can better predict mosquito survival and development, allowing us to better understand disease risk both now and with future warming.

ecology↗

bioRxiv2025

Persistence and near persistence via trait evolution: pathways to coexistence

Modern coexistence theory relies on the invasion criterion: each species must be able to increase when rare in a resident community at ecological equilibrium. However, when considering trait evolution, for example of competing species, this concept must be refined to account for evolution potentially feeding back on population dynamics. We analyze a model of two competing species whose quantitative traits evolve under stabilizing selection, assuming fixed but potentially unequal intraspecific trait variances. Using persistence theory, we derive conditions under which both species persist for all initial trait values, and we introduce the concept of near persistence, in which coexistence holds for a specific, biologically relevant, subset of initial trait configurations. Our analysis reveals that equal trait variances between species, which is commonly assumed in previous work, yield highly specific outcomes and obscure a broader set of coexistence scenarios that emerge under asymmetric trait variation. We identify fifteen distinct qualitative dynamical regimes as a function of initial conditions and trait variances. Moreover, we show that invasion analysis must often be performed at multiple eco-evolutionary equilibria, as invader dynamics may converge to different trait values depending on the ecological and evolutionary context. We discuss the biological implications of these results and perspectives for future work.

ecology↗

bioRxiv2025

A systematic review of climate-change driven range shifts in mosquito vectors

As global temperatures rise, concerns about shifting mosquito ranges--and accompanying changes in the transmission of malaria, dengue, and other diseases--are mounting. However, systematic evidence for climate-driven changes in mosquito ranges remains limited. We conducted a systematic review of studies documenting expansions or contractions in medically important mosquito species. In total, 178 studies on six continents identified range expansions in 118 mosquito species. While over a third of these studies cited warming as a driver, fewer than 10% performed statistical tests of the role of climate. Instead, most expansions were linked to human-aided dispersal (e.g., trade, travel), land-use changes, and urbanization. Although several studies reported poleward or upward expansions consistent with climate warming, none demonstrated warm-edge contractions driven by rising temperatures, which are theoretically predicted in some settings. Rather than expanding into newly suitable areas, many expansions appear to be filling preexisting thermally suitable habitats. Our findings highlight the need for long-term mosquito monitoring, rigorous climate-attribution methods, and better documentation of confounding factors like land-use change and vector control efforts to disentangle climate-driven changes from other anthropogenic factors.

ecology↗

bioRxiv2024

Plasticity in mosquito size and thermal tolerance across a latitudinal climate gradient

Variation in heat tolerance among populations can determine whether a species is able to cope with ongoing climate change. Such variation may be especially important for ectotherms whose body temperatures, and consequently, physiological processes, are regulated by external conditions. Additionally, differences in body size are often associated with latitudinal clines, thought to be driven by climate gradients. While studies have begun to explore variation in body size and heat tolerance within species, our understanding of these patterns across large spatial scales, particularly regarding the roles of plasticity and genetic differences, remains incomplete. Here, we examine body size, as measured by wing length, and thermal tolerance, as measured by the time to immobilization at high temperatures ("thermal knockdown"), in populations of the mosquito Aedes sierrensis collected from across a large latitudinal climate gradient spanning 1300 km (34-44 {degrees}N). We find that mosquitoes collected from lower latitudes and warmer climates were more tolerant of high temperatures than those collected from higher latitudes and colder climates. Moreover, body size increased with latitude and decreased with temperature, a pattern consistent with James rule, which appears to be a result of plasticity rather than genetic variation. Our results suggest that warmer environments produce smaller and more thermally tolerant populations.

ecology↗

bioRxiv2024

Eco-evolutionary dynamics of anthelmintic resistance in soil-transmitted helminths

Anthelmintic resistance (AR) of helminth parasites against the most widely available drugs is an ongoing concern for both human and livestock-infecting species. Indeed, there has been substantial evidence of AR in livestock but less in humans, which may be due to a variety of reasons. In this paper, we develop an eco-evolutionary model that couples the life cycle of these parasites with their underlying evolution in a single biallelic genetic locus that confers resistance to treatment drugs. We determine the critical treatment frequency needed to effectively eliminate the population, for a fixed drug efficacy (without evolution) and use this to classify three qualitative distinct behaviors of the eco-evolutionary model. Then, we describe how aspects of the life cycle influence which qualitative outcome is achieved and the spread of the resistance allele, comparing across parameterized models of human- and livestock-infecting species. For all but one species, we find that lower fecundity rates and lower contact rates speed the spread of resistance, while lower larval death slows it down. The life cycle parameters of Ancylostoma duodenale and Ostertagia circumcincta are associated with the fastest and slowest spread of resistance, respectively. We discuss the mechanistic reason for these results.

ecology↗

bioRxiv2024

How much warming can mosquito vectors tolerate?

Climate warming is expected to substantially impact the global landscape of mosquito-borne disease, but these impacts will vary across disease systems and regions. Understanding which diseases, and where within their distributions, these impacts are most likely to occur is critical for preparing public health interventions. While research has centered on potential warming-driven expansions in vector transmission, less is known about the potential for vectors to experience warming-driven stress or even local extirpations. In conservation biology, species risk from climate warming is often quantified through vulnerability indices such as thermal safety margins - the difference between an organisms upper thermal limit and its habitat temperature. Here, we estimated thermal safety margins for 8 mosquito species (including Aedes aegypti and Anopheles gambiae) that are the vectors of malaria, dengue, chikungunya, Zika, West Nile and other major arboviruses, across their known ranges to investigate which mosquitoes and regions are most and least vulnerable to climate warming. We find that several of the most globally important mosquito vector species have positive thermal safety margins across the majority of their ranges when realistic assumptions of mosquito behavioral thermoregulation are incorporated. On average, the lowest climate vulnerability, in terms of both the magnitude and duration of thermal safety, was just south of the equator and at northern temperate range edges, and the highest climate vulnerability was in the subtropics. Mosquitoes living in regions largely comprised of desert and xeric shrubland biomes, including the Middle East, the western Sahara, and southeastern Australia have the highest climate vulnerability across vector species.

ecology↗

bioRxiv2023

Temperature and intraspecific variation affect host-parasite interactions

Parasites play key roles in regulating aquatic ecosystems, yet the impact of climate warming on their ecology and disease transmission remains poorly understood. Isolating the effect of warming is challenging as transmission involves multiple interacting species and potential intraspecific variation in temperature responses of one or more of these species. Here, we leverage a wide-ranging mosquito species and its facultative parasite as a model system to investigate the impact of temperature on host-parasite interactions and disease transmission. We conducted a common garden experiment measuring parasite growth and infection rates at seven temperatures using 12 field-collected parasite populations and a single mosquito population. We find that both free-living growth rates and infection rates varied with temperature, which were highest at 18-24.5{degrees}C and 13{degrees}C, respectively. Further, we find intraspecific variation in peak performance temperature reflecting patterns of local thermal adaptation--parasite populations from warmer source environments typically had higher thermal optima for free-living growth rates. For infection rates, we found a significant interaction between parasite population and nonlinear effects of temperature. These findings underscore the need to consider both host and parasite thermal responses, as well as intraspecific variation in thermal responses, when predicting the impacts of climate change on disease in aquatic ecosystems.

ecology↗

bioRxiv2023

A mosquito parasite is locally adapted to its host but not temperature

Climate change will alter interactions between parasites and their hosts. Warming may affect patterns of local adaptation, shifting the environment to favor the parasite or host and thus changing the prevalence of disease. We assessed local adaptation in the facultative ciliate parasite Lambornella clarki, which infects the western tree hole mosquito Aedes sierrensis. We conducted laboratory infection experiments with mosquito larvae and parasites collected from across a climate gradient, pairing sympatric or allopatric populations across three temperatures that were either matched or mismatched to the source environment. L. clarki parasites were locally adapted to their hosts, with 2.6x higher infection rates on sympatric compared to allopatric populations, but were not locally adapted to temperature. Infection peaked at the intermediate temperature of 13{degrees}C. Our results highlight the importance of host selective pressure on parasites, despite the impact of temperature on infection success.

ecology↗

bioRxiv2021

Thermal asymmetries influence effects of warming on stage and size-dependent predator-prey interactions

Climate warming directly influences the developmental and feeding rates of organisms. Changes in these rates are likely to have consequences for species interactions, particularly for organisms affected by stage- or size-dependent predation. However, because of differences in species-specific responses to warming, predicting the impact of warming on predator and prey densities can be difficult. We present a general model of stage-dependent predation with temperature-dependent vital rates to explore the effects of warming when predator and prey have different thermal optima. We found that warming generally favored the interactor with the higher thermal optimum. Part of this effect occurred due to the stage-dependent nature of the interaction, and part due to thermal asymmetries. Furthermore, large differences in thermal optima between predators and prey (i.e., a high degree of asymmetry) led to a weaker interaction. Interestingly, below the predator and prey thermal optima, warming caused prey densities to decline, even as increasing temperature improved prey performance. We also parameterize our model using values from a well-studied system, Arctia virginalis and Formica lasioides, in which the predator has a warmer optimum. Overall, our results provide a general framework for understanding stage- and temperature-dependent predator-prey interactions, and illustrate that the thermal niche of both predator and prey are important to consider when predicting the effects of climate warming.

ecology↗

bioRxiv2020

Evolution in response to extreme events: good or bad?

Climate change is predicted to increase the severity of environmental perturbations, including storms and droughts, which act as strong selective agents. These extreme events are often of finite duration (pulse disturbances). Hence, while evolution during an extreme event may be adaptive, the resulting phenotypic changes may become maladaptive when the event ends. Using individual-based models and analytic approximations that fuse quantitative genetics and demography, we explore how heritability and phenotypic variance affect population size and extinction risk in finite populations under an extreme event of fixed duration. Since more evolution leads to greater maladaptation and slower population recovery following an extreme event, slowing population recovery, greater heritability can increase extinction risk when the extreme event is short, as in random environments with low autocorrelation. Alternatively, when an extreme event is sufficiently long, heritability often helps a population persist, as under a press perturbation. We also find that when events are severe, the buffering effect of phenotypic variance can outweigh the increased load it causes. Our results highlight the importance of the length and severity of a disturbance when assessing the role of evolution on population recovery; the rapid adaptive evolution observed during extreme events may be bad for persistence.

evolutionary biology↗

bioRxiv2019

Antagonistic coevolution between multiple quantitative traits: matching interactions can be subsets of difference interactions

AO_SCPLOWBSTRACTC_SCPLOWCoevolution is one of the major drivers of complex dynamics in population ecology. Historically, antagonistic coevolution in victim-exploiter systems has been a topic of special interest, and involves traits with various genetic architectures (e.g., the number of genes involved) and effects on interactions. For example, exploiters may need to have traits that \"match\" those of victims for successful exploitation (i.e., a matching interaction), or traits that exceed those of victims (i.e., a difference interaction). Different models exist which are appropriate for different types of traits, including Mendelian (discrete) and quantitative (continuous) traits. For models with multiple Mendelian traits, recent studies have shown that antagonistic coevolutionary patterns that appear as matching interactions can arise due to multiple difference interactions with costs of having large trait values. Here we generalize their findings to quantitative traits and show, analogously, that the multidimensional difference interactions with costs sometimes behave qualitatively the same as matching interactions. While previous studies in quantitative genetics have used the dichotomy between matching and difference frameworks to explore coevolutionary dynamics, we suggest that exploring multidimensional trait space is important to examine the generality of results obtained from one-dimensional traits.

evolutionary biology↗