Raymond B Huey

• Ph.D. Biology Harvard Univ
• Professor Emeritus at University of Washington

Synopsis The fitness implications of climate variability and change are often estimated by integrating an organism's thermal sensitivity of performance across a time series of experienced body temperatures. Although this approach is an important first step in evaluating an organism's sensitivity to climate or climate change, it ignores potential in...

Climate warming can induce a cost-of-living “squeeze” in ectotherms by increasing energetic expenditures while reducing foraging gains. We used biophysical models (validated by 2685 field observations) to test this hypothesis for 10 ecologically diverse lizards in African and Australian deserts. Historical warming (1950–2020) has been more intense...

Recent climate change should result in expansion of species to northern or high elevation range margins, and contraction at southern and low elevation margins in the northern hemisphere, because of local extirpations or range shifts or both. We combined museum occurrence records from both the continental U.S. and Mexico with a new eco-physiological...

Parents often weigh social, familial, and cultural considerations when choosing their baby's name, but the name they choose could potentially be influenced by their physical or biotic environments. Here we examine whether the popularity of month and season names of girls covary geographically with environmental variables. In the continental USA, Ap...

Aim 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 t...

Synopsis 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 i...

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...

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...

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...

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...

Time at high temperature modulates fly mortality in nature

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...

Warming, crops, and insect pests Crop responses to climate warming suggest that yields will decrease as growing-season temperatures increase. Deutsch et al. show that this effect may be exacerbated by insect pests (see the Perspective by Riegler). Insects already consume 5 to 20% of major grain crops. The authors' models show that for the three mos...

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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 ( T b ) experienced during activity. For several complementary reasons, physiological ecologists have long expected that T b distributions during activity should have a long left tail (left‐skewed), but only infreque...

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 in the northern hemisphere, because of local extirpations or range shifts or both. We combined museum occurrence records from both the continental U.S. and Mexico with a new eco-physiological...

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...

Frigate birds forage over vast distances by getting boosts from thermals and trade winds

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...

Significance We find that most terrestrial ectotherms are insufficiently tolerant of high temperatures to survive the warmest potential body temperatures in exposed habitats and must therefore thermoregulate by using shade, burrows, or evaporative cooling. Our results reveal that exposure to extreme heat can occur even at high elevations and latitu...

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...

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...

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...

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...

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...

Drosophila subobscura is a Palearctic species that was first observed in South and North America in the early 1980s, and that rapidly invaded broad latitudinal ranges on both continents. To trace the source and history of this invasion, we obtained genotypic data on nine microsatellite loci from two South American, two North American and five Europ...

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...

This book shows that the field of foraging biology of reptiles is alive and well. We find this exciting, as we've been interested in this field for four decades. No doubt for that reason, we've been asked to describe the history of our thinking about foraging modes. How did we become involved? What were some of the salient experiences we had, and w...

Rodríguez-Trelles and Rodríguez advocate standardizing old and new collections by climate rather than by calendar and also propose that some of our samples were biased by inappropriate timing. Their first suggestion applies to few species, and its implementation alters photoperiodic cues. Their second point is valid, but our conclusions are robust:...

Diverse biochemical and physiological adaptations enable different species of ectotherms to survive and reproduce in very different temperature regimes, but whether these adaptations fully compensate for the thermodynamically depressing effects of low temperature on rates of biological processes is debated. If such adaptations are fully compensator...

Comparisons of recent with historical samples of chromosome inversion frequencies provide opportunities to determine whether genetic change is tracking climate change in natural populations. We determined the magnitude and direction of shifts over time (24 years between samples on average) in chromosome inversion frequencies and in ambient temperat...

In 2005, The American Physiological Society initiated The Living History of Physiology Project to recognize senior members who have made extraordinary contributions during their career to the advancement of the discipline and profession of physiology. Each Eminent Physiologist will be interviewed for archival purposes, and the video tape will be av...

Synopsis In 1967 Daniel Janzen published an influential paper titled "Why Mountain Passes Are Higher in the Tropics." Janzen derived a simple climatic-physiological model predicting that tropical mountain passes would be more effective barriers to organismal dispersal than would temperate-zone passes of equivalent altitude. This prediction derived...

The Drosophila obscura clade consists of about 41 species, of which 20 were used for analyses of wing and thorax length. Our primary goal was to investigate the magnitude of sexual size dimorphism (SSD) of these traits within this clade and to test Rensch's Rule [when females are larger than males, SSD (e.g., female/male ratio) should decrease with...

Letters Section Editor: Robert M. Golub, MD, Senior Editor.

We examined museum specimens of the Common Barking Gecko (Ptenopus garrulus) from the Kalahari and Namib Deserts to assess sexual size dimorphism, reproductive status, and diet. Males had significantly wider heads than females of the same body size; however, P. garrulus showed no sexual dimorphism in any other morphological character. The smallest...

A catastrophic extinction occurred at the end of the Permian Period. However, baseline extinction rates appear to have been elevated even before the final catastrophe, suggesting sustained environmental degradation. For terrestrial vertebrates during the Late Permian, the combination of a drop in atmospheric oxygen plus climate warming would have i...

Starvation resistance is often measured in physiological studies with Drosophila and other insects. One common method involves measuring time until death of groups of insects. This method assumes that survivors are not obtaining nutrition from their vial mates that die early. However, because some Drosophila larvae can scavenge carcasses, this grou...

Drosophila subobscura is a European (EU) species that was introduced into South America (SA) approximately 25 years ago. Previous studies have found rapid clinal evolution in wing size and in chromosome inversion frequency in the SA colonists, and these clines parallel those found among the ancestral EU populations. Here we examine thermoplastic ch...

Drosophila subobscura is geographically widespread in the Old World. Around the late 1970s, it was accidentally introduced into both South and North America, where it spread rapidly over broad latitudinal ranges. This invading species offers opportunities to study the speed and predictability of trait evolution on a geographic scale. One trait of s...

Similarity of dispersal behavior among siblings is common in vertebrates. However, little is known about the factors (genetic, prenatal, postnatal) generating this similarity. Here we analyzed potential influences on the dispersal patterns of multiple families of hatchling fence lizards, Sceloporus occidentalis. We captured near-term females from t...