Raymond B Huey

University of Washington Seattle | UW · Department of Biology

Understanding and predicting the biological consequences of climate change requires considering the thermal sensitivity of organisms relative to environmental temperatures. One common approach involves ‘thermal safety margins’ (TSMs), which are generally estimated as the temperature differential between the highest temperature an organism can toler...

Organisms living in seasonal environments often adjust physiological capacities and sensitivities in response to (or in anticipation of) environment shifts. Such physiological and morphological adjustments (“acclimation” and related terms) inspire opportunities to explore the mechanistic bases underlying these adjustments, to detect cues inducing a...

An ecological issue can best be studied by gathering original data that are specifically targeted for that issue. But ascer-taining—a priori—whether a novel issue will be worth exploring can be problematic without background data. However, an issue’s potential merit can sometimes be evaluated by repurposing legacy or other data that had been gather...

In cold environments ectotherms can be dormant underground for long periods. In 1941 Cowles proposed an ecological trade‐off involving the depth at which ectotherms overwintered: on warm days, only shallow reptiles could detect warming soils and become active; but on cold days, they risked freezing. Cowles discovered that most reptiles at a desert...

Body size affects the body temperature of an ectotherm by altering both heating rates and the microclimate experienced. These joint effects are rarely considered in the analyses of climatic constraints on ectotherms but nonetheless influence body temperatures and thus activity periods and foraging opportunities. Here we develop and test transient h...

Biological invasions have increased in the last few decades mostly due to anthropogenic causes such as globalization of trade. Because invaders sometimes cause large economic losses and ecological disturbances, estimating their origin and potential geographical ranges is useful. Drosophila subobscura is native to the Old World but was introduced in...

Mount Everest is an extreme environment for humans. Nevertheless, hundreds of mountaineers attempt to summit Everest each year. In a previous study we analyzed interview data for all climbers (2,211) making their first attempt on Everest during 1990–2005. Probabilities of summiting were similar for men and women, declined progressively for climbers...

Because Puerto Rico has warmed in recent decades, ectotherms there should have shifted their elevational ranges uphill. However, by comparing historical versus recent distributional records of Anolis lizards, we found that three "montane-forest" species have instead moved downhill in recent decades, almost to sea level. This downward shift appears...

Climate warming may lower environmental resource levels, growth, and fitness of many ectotherms. In a classic experiment, Brett and colleagues documented that growth rates of salmon depended strikingly on both temperature and food levels. Here we develop a simple bioenergetic model that explores how fixed temperatures and food jointly alter the the...

The comparative method has long been a fundamental exploratory tool in evolutionary biology, but this venerable approach was revolutionized in 1985, when Felsenstein published “Phylogenies and the Comparative Method” in The American Naturalist. This article forced comparative biologists to start thinking phylogenetically when conducting statistical...

Insect pests substantially reduce yields of three staple grains—rice, maize, and wheat—but models assessing the agricultural impacts of global warming rarely consider crop losses to insects. We use established relationships between temperature and the population growth and metabolic rates of insects to estimate how and where climate warming will au...

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Aim The evolution of viviparity in squamate reptiles has attracted considerable scientific attention since the beginning of last century. The cold‐climate hypothesis posits that cold regions favor viviparity (and therefore the incidence of viviparous squamates is increased in these regions) because viviparous females can use thermoregulatory behavi...

In 1967, Dan Janzen published “Why Mountain Passes Are Higher in the Tropics” in The American Naturalist. Janzen’s seminal article has captured the attention of generations of biologists and continues to inspire theoretical and empirical work. The underlying assumptions and derived predictions are broadly synthetic and widely applicable. Consequent...

The US and Mexico share a common history in many areas, including language and culture. They face ecological changes due to the increased frequency and severity of droughts and rising energy demands; trends that entail economic costs for both nations and major implications for human well being. We describe an ongoing effort by the Environment Worki...

The performance of ectotherms integrated over time depends in part on the position and shape of the distribution of body temperatures (Tb) experienced during activity. For several complementary reasons, physiological ecologists have long expected that Tb distributions during activity should have a long left tail (left-skewed); but only infrequently...

Recent climate change should result in expansion of species to northern or high elevation range margins,

Recent climate change should result in expansion of species to northern or high elevation range margins, and contraction at southern and low elevation margins due to extinction. Climate models predict dramatic extinctions and distributional shifts in the next century, but there are few ground-truths of these dire forecasts leading to uncertainty in...

Extreme events can be a major driver of evolutionary change over geological and contemporary timescales. Outstanding examples are evolutionary diversification following mass extinctions caused by extreme volcanism or asteroid impact. The evolution of organisms in contemporary time is typically viewed as a gradual and incremental process that result...

Thermal performance curves (TPCs), which quantify how an ectotherm's body temperature (Tb) affects its performance or fitness, are often used in an attempt to predict organismal responses to climate change. Here, we examine the key ? but often biologically unreasonable ? assumptions underlying this approach; for example, that physiology and thermal...

SynopsisUnderstanding the biological impacts of extreme temperatures requires translating meteorological estimates into organismal responses, but that translation is complex. In general, the physiological stress induced by a given thermal extreme should increase with the extreme's magnitude and duration, though acclimation may buffer that stress. H...

Extreme temperatures can injure or kill organisms and can drive evolutionary patterns. Many indices of extremes have been proposed; but few attempts have been made to establish geographic patterns of extremes and to evaluate whether they align with geographic patterns in biological vulnerability and diversity. To examine these issues, we adopt the...

Reproductive phenology often varies geographically within species, driven by environmental gradients that alter growth and reproduction. However, environments can differ between adjacent habitats at single localities. In lowland Puerto Rico, both open (sunny, warm) and forested (shady, cool) habitats may be only meters apart. The lizard Anolis cris...

Warming of the oceans and consequent loss of dissolved oxygen (O2) will alter marine ecosystems, but a mechanistic framework to predict the impact of multiple stressors on viable habitat is lacking. Here, we integrate physiological, climatic, and biogeographic data to calibrate and then map a key metabolic index-the ratio of O2 supply to resting me...

Physiological thermal-tolerance limits of terrestrial ectotherms often exceed local air temperatures, implying a high degree of thermal safety (an excess of warm or cold thermal tolerance). However, air temperatures can be very different from the equilibrium body temperature of an individual ectotherm. Here, we compile thermal-tolerance limits of e...

Species-rich adaptive radiations typically diversify along several distinct ecological axes, each characterized by morphological, physiological, and behavioral adaptations. We test here whether different types of adaptive traits share similar patterns of evolution within a radiation by investigating patterns of evolution of morphological traits ass...

Good scientific research yields insights that are important and general. But the process of learning to do good science is far from simple, and the inherent challenges are often more motivational than scientific. I review various ways that may help scientists (especially young ones) to do better research. Perhaps the most important is to spend time...

A recently developed integrative framework proposes that the vulnerability of a species to environmental change depends on the species' exposure and sensitivity to environmental change, its resilience to perturbations and its potential to adapt to change. These vulnerability criteria require behavioural, physiological and genetic data. With this in...

To a first order, the oxygen content of the ocean interior is determined by the influx of the gas across the air-sea surface (i.e., ventilation) and consumption due primarily to microbial respiration. As these two competing processes vary in space and time, so does the concentration of oxygen in the ocean interior. Although oxygen concentrations on...

For more than a century, biologists have known that body temperature strongly affects the capacities and rates of organisms and thus is a key determinant of organismal performance and Darwinian fitness (1⇓–3). Although rate/temperature (RT) relationships have been quantified for many traits and taxa, interest in RT studies is being revitalized beca...

Fig. S3. Temperature dependence of the intrinsic rate of increase (r) in four strains of C. elegans.

Fig. S1. Temperature-dependent fitness response in the standard lab strain N2.

Fig. S2. Temperature dependence of Lifetime Reproductive Success (LRS) in four strains of C. elegans.

A central premise of physiological ecology is that an animal's preferred body temperature should correspond closely with the temperature maximizing performance and Darwinian fitness. Testing this co-adaptational hypothesis has been problematic for several reasons. First, reproductive fitness is the appropriate measure, but is difficult to measure i...

Parallel latitudinal clines across species and continents provide dramatic evidence of the efficacy of natural selec- tion, however little is known about the dynamics involved in cline formation. For example, several drosophilids and other ectotherms increase in body and wing size at higher latitudes. Here we compare evolution in an ancestral Europ...

Background: About 30 years ago, the Palaearctic fly Drosophila subobscura successfully invaded the New World, where parasitoid species diversity was thought to be lower than in the Old World. Hypotheses: Because parasitoids cause major mortality to Drosophila, the invader should benefit from escaping its natural parasitoid enemies and enjoy lower r...

Documented shifts in geographical ranges, seasonal phenology, community interactions, genetics and extinctions have been attributed to recent global warming. Many such biotic shifts have been detected at mid- to high latitudes in the Northern Hemisphere-a latitudinal pattern that is expected because warming is fastest in these regions. In contrast,...

Background/Question/Methods Climate change poses both direct and indirect threats to global food security. Over 800 million people are malnourished today, 95% of these people are in tropical or subtropical areas, and estimates suggest this number will grow substantially with climate change. Estimating the effects of climate change on global food...

Warming is held responsible for a rash of extinctions of global lizard populations.

Introduction. Body temperature influences all aspects of the physiology and ecology of insects and indeed of all other ectotherms (Cossins and Bowler, 1987; Chown and Nicolson, 2004; Angilletta, 2009). Extreme low or high temperatures are physiologically damaging or even lethal, but temperatures well within those critical limits have profound effec...

This chapter looks critically at a particular type of experimental evolution, often called laboratory natural selection (LNS). In this protocol, stocks of organisms are reared chronically under different conditions and allowed to evolve by natural selection over many generations. The chapter discusses the difficulties of balancing simplicity and re...

Despite decades of research on the evolution of thermal physiology, at least one fundamental issue remains unresolved: whether the maximal performance of a genotype depends on its optimal temperature. One school argues that warm-adapted genotypes will outperform cold-adapted genotypes because high temperatures inevitably accelerate chemical reactio...

Background/Question/Methods: Biological impacts of climate warming are predicted to increase with latitude, paralleling increases in warming. However, the magnitude of impacts depends not only on the degree of warming but also on the number of species at risk, their sensitivity to warming and their options for compensation. Lizards are useful for e...

The Palaearctic species Drosophila subobscura recently invaded the west coast of Chile and North America. This invasion helped to corroborate the adaptive value of the rich chromosomal polymorphism of the species, as the same clinal patterns than those observed in the original Palaearctic area were reproduced in the colonized areas in a relatively...

In fewer than two decades after invading the Americas, the European fly Drosophila subobscura evolved latitudinal clines in several traits. Moreover, its chromosomal inversion frequencies at given localities have shifted with climate warming. Temperature may have driven the evolution of both geographic clines and within-site shifts. Nevertheless, w...

Rising air temperatures around the globe are affecting organismal abundance, distribution, and evolution (1, 2). Not surprisingly, biologists are endeavoring to assess and anticipate further impacts of warming. What is usually overlooked in these efforts is the fact that mobile organisms are not prisoners of climate warming: they can use behavioral...

Biological impacts of climate warming are predicted to increase with latitude, paralleling increases in warming. However, the magnitude of impacts depends not only on the degree of warming but also on the number of species at risk, their physiological sensitivity to warming and their options for behavioural and physiological compensation. Lizards a...

Environmental temperature strongly affects physiology of ectotherms. Small ectotherms, like Drosophila, cannot endogenously regulate body temperature so must rely on behavior to maintain body temperature within a physiologically permissive range. Here we review what is known about Drosophila thermal preference. Work on thermal behavior in this grou...

Knowledge of the frequency, distribution, and fate of lethal genes in chromosomal inversions helps to illuminate the evolution of recently founded populations. We analyze the relationship between lethal genes and inversions in two colonizing populations of D. subobscura in Chile. In the ancestral Palearctic populations of this species, lethal genes...

George A. Bartholomew was one of the most influential organismal biologists of the twentieth century. His insights and research were fundamental to the establishment and growth of physiological ecology and evolutionary physiology. In the process of fostering that area of science, he created a body of literature that is striking in the clarity of it...

As invading species expand, they eventually encounter physical and biotic stressors that limit their spread. We examine latitudinal and climatic variation in physiological tolerance in one native and two invading populations of Drosophila subobscura. These flies are native to the Palearctic region, but invaded both South and North America around 19...

Tropical animals may be particularly vulnerable to climate warming.

The impact of anthropogenic climate change on terrestrial organisms is often predicted to increase with latitude, in parallel with the rate of warming. Yet the biological impact of rising temperatures also depends on the physiological sensitivity of organisms to temperature change. We integrate empirical fitness curves describing the thermal tolera...

Salmon life histories are finely tuned to local environmental conditions, which are intimately linked to climate. We summarize the likely impacts of climate change on the physical environment of salmon in the Pacific Northwest and discuss the potential evolutionary consequences of these changes, with particular reference to Columbia River Basin spr...

Body temperature (T(b)) profoundly affects the fitness of ectotherms. Many ectotherms use behavior to control T(b) within narrow levels. These temperatures are assumed to be optimal and therefore to match body temperatures (Trmax) that maximize fitness (r). We develop an optimality model and find that optimal body temperature (T(o)) should not be c...

Question: Associations of body size and of body temperature with fitness have complex relationships for ectotherms, but three general patterns are known. Bigger is better: Larger body size is frequently associated with greater fitness within populations. Hotter is smaller: Smaller adult body sizes typically result from development at higher tempera...

Increasing numbers of climbers are attempting Mount Everest, the highest mountain on Earth. We compiled interview data and computed the probabilities of summiting and of dying as a function of climber age and gender (2211 climbers, spring season) for the period of 1990-2005. Men and women had similar odds of summiting and of dying. However, climber...

For more than six decades, physiological ecologists have intensively studied diverse aspects of lizard thermal biology. Nevertheless, a recent review notes that prior studies have generally ignored gender differences in body temperatures, thermal sensitivity, or other aspects of thermal biology. We concur that gender differences have been ignored a...

The preferred body temperature of ectotherms is typically inferred from the observed distribution of body temperatures in a laboratory thermal gradient. For very small organisms, however, that observed distribution might misrepresent true thermal preferences. Tiny ectotherms have limited thermal inertia, and so their body temperature and speed of m...

For more than six decades, physiological ecologists have intensively studied diverse aspects of lizard thermal biology. Nevertheless, a recent review notes that prior studies have generally ignored gender differences in body temperatures, thermal sensitivity, or other aspects of thermal biology. We concur that gender differences have been ignored a...

The physiological and life history consequences of chronic temperatures are well studied in ectotherms. However, little is known about the consequences of short-term exposure to unusually high or low temperatures, as would occur during a weather front. What are the immediate life-history effects of such thermal transients? Can ectotherms recover qu...