Evolutionary Physiology Research Articles

Professor Natal’ya N. Traugott’s Contribution to Studies on the Development of Central Speech Mechanisms

The name of Natal’ya Nikolaevna Traugott is closely associated with the history of human higher nervous activity studies in Russia. Destiny gifted to N.N. Traugott the opportunity to communicate with many outstanding scientists; she regularly attended the “Pavlov Wednesdays”, took part in V.M. Bechterev’s clinical discussions, visited L.S. Vygotskii’s lectures on the problems of children higher psychic functions development. For many years N.N. Traugott had a professional relationship with A.R. Luriya and his colleagues, at the suggestion of L.A. Orbeli she had headed the laboratory of pathology of higher nervous function from the beginning of 1956. The paramount importance for the development of new directions in evolutionary physiology had N.N. Traugott’s works on the principles of cortical dysfunction in different psychopathological conditions and her recommendations aimed at a strategy for individual corrections of speech in children.

Urine: Waste product or biologically active tissue?

Historically, urine has been viewed primarily as a waste product with little biological role in the overall health of an individual. Increasingly, data suggest that urine plays a role in human health beyond waste excretion. For example, urine might act as an irritant and contribute to symptoms through interaction with-and potential compromise of-the urothelium. To explore the concept that urine may be a vehicle for agents with potential or occult bioactivity and to discuss existing evidence and novel research questions that may yield insight into such a role, the National Institute of Diabetes and Digestive and Kidney Disease invited experts in the fields of comparative evolutionary physiology, basic science, nephrology, urology, pediatrics, metabolomics, and proteomics (among others) to a Urinology Think Tank meeting on February 9, 2015. This report reflects ideas that evolved from this meeting and current literature, including the concept of urine quality, the biological, chemical, and physical characteristics of urine, including the microbiota, cells, exosomes, pH, metabolites, proteins, and specific gravity (among others). Additionally, the manuscript presents speculative, and hopefully testable, ideas about the functional roles of urine constituents in health and disease. Moving forward, there are several questions that need further understanding and pursuit. There were suggestions to consider actively using various animal models and their biological specimens to elaborate on basic mechanistic information regarding human bladder dysfunction.

Improved non-destructive 2D and 3D X-ray imaging of leaf venation

BackgroundLeaf venation traits are important for many research fields such as systematics and evolutionary biology, plant physiology, climate change, and paleoecology. In spite of an increasing demand for vein trait data, studies are often still data-limited because the development of methods that allow rapid generation of large sets of vein data has lagged behind. Recently, non-destructive X-ray technology has proven useful as an alternative to traditional slow and destructive chemical-based methods. Non-destructive techniques more readily allow the use of herbarium specimens, which provide an invaluable but underexploited resource of vein data and related environmental information. The utility of 2D X-ray technology and microfocus X-ray computed tomography, however, has been compromised by insufficient image resolution. Here, we advanced X-ray technology by increasing image resolution and throughput without the application of contrast agents.ResultsFor 2D contact microradiography, we developed a method which allowed us to achieve image resolutions of up to 7 µm, i.e. a 3.6-fold increase compared to the industrial standard (25 µm resolution). Vein tracing was further optimized with our image processing standards that were specifically adjusted for different types of leaf structure and the needs of higher imaging throughput. Based on a test dataset, in 91% of the samples the 7 µm approach led to a significant improvement in estimations of minor vein density compared to the industrial standard. Using microfocus X-ray computed tomography, very high-resolution images were obtained from a virtual 3D–2D transformation process, which was superior to that of 3D images.ConclusionsOur 2D X-ray method with a significantly improved resolution advances rapid non-destructive bulk scanning at a quality that in many cases is sufficient to determine key venation traits. Together with our high-resolution microfocus X-ray computed tomography method, both non-destructive approaches will help in vein trait data mining from museum collections, which provide an underexploited resource of historical and recent data on environmental and evolutionary change. In spite of the significant increase in effective image resolution, a combination of high-throughput and full visibility of the vein network (including the smallest veins and their connectivity) remains challenging, however.

Risk factors and coping strategies of severe community-acquired pneumonia in chemotherapy induction period of acute leukemia.

The risk factors and coping strategies of severe community-acquired pneumonia (SCAP) in chemotherapy induction period of acute leukemia were investigated. Eighty-six patients with CAP in chemotherapy induction period of acute leukemia in Dezhou Hospital from March 2014 to February 2017 were selected and divided into observation group (SCAP group, n=45) and control group (non-SCAP group, n=41) according to the acute physiology and chronic health evolution II (APACHE II) score. The blood, sputum, nasopharyngeal secretion and pleural effusion samples were collected from patients in both groups, and the samples were detected for pathogens, followed by the analysis of relevant factors. The dynamic changes in the sequential organ failure assessment (SOFA) score, procalcitonin (PCT), D-dimer (D-D) and C-reactive protein (CRP) levels in patients were observed before and after the corresponding treatment strategies were taken. The total distribution ratio of pathogens from high to low in the two groups was as follows: bacterium, virus, fungus, mycoplasma and chlamydia trachomatis; there was no significant difference between the two groups (P>0.05). Logistic regression analysis showed that the repeated infection (OR=3.315, P=0.005), multi-resistant bacterial infection (OR=1.915, P=0.008) and D-D (OR=1.936, P=0.009) were independent risk factors for SCAP (P<0.05). After different coping strategies were taken, the SOFA score, PCT, D-D and CRP levels in the two groups were significantly decreased, and they were obviously higher in observation group than those in control group (P<0.05). Repeated infection, D-D level and multi-resistant bacterial infection are the risk factors affecting the SCAP in chemotherapy induction period of acute leukemia. The coping strategies can effectively relieve the patient's condition, reduce the severity of disease and improve the survival rate of patients.

Environmental adaptation of Acanthamoeba castellanii and Entamoeba histolytica at genome level as seen by comparative genomic analysis.

Amoebozoans are in many aspects interesting research objects, as they combine features of single-cell organisms with complex signaling and defense systems, comparable to multicellular organisms. Acanthamoeba castellanii is a cosmopolitan species and developed diverged feeding abilities and strong anti-bacterial resistance; Entamoeba histolytica is a parasitic amoeba, who underwent massive gene loss and its genome is almost twice smaller than that of A. castellanii. Nevertheless, both species prosper, demonstrating fitness to their specific environments. Here we compare transcriptomes of A. castellanii and E. histolytica with application of orthologs' search and gene ontology to learn how different life strategies influence genome evolution and restructuring of physiology. A. castellanii demonstrates great metabolic activity and plasticity, while E. histolytica reveals several interesting features in its translational machinery, cytoskeleton, antioxidant protection, and nutritional behavior. In addition, we suggest new features in E. histolytica physiology that may explain its successful colonization of human colon and may facilitate medical research.

Plantar mechanical stimulation prevents neurochemical alterations in the hippocampus induced by stimulated microgravity

Plantar mechanical stimulation prevents neurochemical alterations in the hippocampus induced by stimulated microgravity

Hair coat properties of donkeys, mules and horses in a temperate climate.

SummaryBackgroundThere are clear differences between donkeys and horses in their evolutionary history, physiology, behaviour and husbandry needs. Donkeys are often kept in climates that they are not adapted to and as such may suffer impaired welfare unless protection from the elements is provided.ObjectivesTo compare some of the hair coat properties of donkeys, mules and horses living outside, throughout the year, in the temperate climate of the UK.Study designLongitudinal study.MethodsHair samples were taken from 42 animals: 18 donkeys (4 females, 14 males), 16 horses (6 females, 10 males) and eight mules (5 females, 3 males), in March, June, September and December. The weight, length and width of hair were measured, across the four seasons, as indicators of the hair coat insulation properties.ResultsDonkeys’ hair coats do not significantly differ across the seasons. All three measurements of the insulation properties of the hair samples indicate that donkeys do not grow a winter coat and that their hair coat was significantly lighter, shorter and thinner than that of horses and mules in winter. In contrast, the hair coats of horses changed significantly between seasons, growing thicker in winter.Main limitationsThe measurements cover only a limited range of features that contribute to the thermoregulation of an animal. Further research is needed to assess shelter preferences by behavioural measures, and absolute heat loss via thermoimaging.ConclusionsDonkeys, and to a lesser extent mules, appear not to be as adapted to colder, wet climates as horses, and may therefore require additional protection from the elements, such as access to a wind and waterproof shelter, in order for their welfare needs to be met.

Behavioral compensation buffers body temperatures of two Liolaemus lizards under contrasting environments from the temperate Pampas: a Bogert effect?

Postural adjustments and microhabitat selection are two behavioral mechanisms that lizards extensively use to regulate their body temperatures. The Bogert effect occurs when behavioral thermoregulation buffers potential changes in body temperatures of congeneric organisms due to environmental variation, in turn precluding physiological evolution. We compared field body temperatures (Tb) and behavioral thermoregulation traits between two Liolaemus lizards: the saxicolous Liolaemus tandiliensis and the arenicolous Liolaemus wiegmannii. These species are spatially segregated in two thermally contrasting environments from the SE of the temperate Pampas of Argentina. During summer, the mean operative temperature (Te) of the coastal sand dunes occupied by L. wiegmannii was 9 ºC higher than that of the Tandilia mountains inhabited by L. tandiliensis. Despite the contrasting thermal conditions of both habitats, the mean Tb of L. tandiliensis (34.72 °C) was similar to that of L. wiegmannii (35.01 °C). The behavioral thermoregulation mechanisms varied considerably between both species. Liolaemus tandiliensis combined static body posture with displacements towards sunlit areas. In contrast, L. wiegmannii combined elevated and prostrated body postures with movements towards full and filtered sun patches. Environmental gradients offer diverse challenges impelling lizards to find different behavioral thermoregulation adaptations in order to partially cope with environmental constraints. This occurs in many species of Liolaemus that are thermoregulatory efficient despite of the climatic adversities. In this study, two species of Liolaemus used different postural and microhabitat path-selection strategies according to climate, allowing them to buffer changes in Tb, thus suggesting that the Bogert effect may be occurring in these two species.

Thermoregulatory Behavior Simultaneously Promotes and Forestalls Evolution in a Tropical Lizard

The role of behavior in evolution has long been discussed, with some arguing that behavior promotes evolution by exposing organisms to selection (behavioral drive) and others proposing that it inhibits evolution by shielding organisms from environmental variation (behavioral inertia). However, this discussion has generally focused on the effects of behavior along a single axis without considering that behavior simultaneously influences selection in various niche dimensions. By examining evolutionary change along two distinct niche axes-structural and thermal-we propose that behavior simultaneously drives and impedes evolution in a group of Anolis lizards from the Caribbean island of Hispaniola. Specifically, a behavioral shift in microhabitat to boulders at high altitude enables thermoregulation, thus forestalling physiological evolution in spite of colder environments. This same behavioral shift drives skull and limb evolution to boulder use. Our results emphasize the multidimensional effects of behavior in evolution. These findings reveal how, rather than being diametrically opposed, niche conservatism and niche lability can occur simultaneously. Furthermore, patterns of niche evolution may vary at different geographic scales: because of thermoregulatory behavior, lizards at high and low elevation share similar microclimatic niches (consistent with niche conservatism) while inhabiting distinct macroclimatic environments (consistent with niche divergence). Together, our results suggest that behavior can connect patterns of niche divergence and conservatism at different geographic scales and among traits.

Specialized stomatal humidity responses underpin ecological diversity in C3 bromeliads.

The Neotropical Bromeliaceae display an extraordinary level of ecological variety, with species differing widely in habit, photosynthetic pathway and growth form. Divergences in stomatal structure and function, hitherto understudied in treatments of bromeliad evolutionary physiology, could have been critical to the generation of variety in ecophysiological strategies among the bromeliads. Because humidity is a key factor in bromeliad niches, we focussed on stomatal responses to vapour pressure deficit (VPD). We measured the sensitivity of stomatal conductance and assimilation rate to VPD in eight C3 bromeliad species of contrasting growth forms and ecophysiological strategies and parameterised the kinetics of stomatal responses to a step change in VPD. Notably, three tank-epiphyte species displayed low conductance, high sensitivity and fast kinetics relative to the lithophytes, while three xeromorphic terrestrial species showed high conductance and sensitivity but slow stomatal kinetics. An apparent feedforward response of transpiration to VPD occurred in the tank epiphytes, while water-use efficiency was differentially impacted by stomatal closure depending on photosynthetic responses. Differences in stomatal responses to VPD between species of different ecophysiological strategies are closely linked to modifications of stomatal morphology, which we argue has been a pivotal component of the evolution of high diversity in this important plant family.

Effects of fat and exoskeletal mass on the mass scaling of metabolism in Carabidae beetles

The rate at which organisms metabolize resources and consume oxygen is tightly linked to body mass. Typically, there is a sub-linear allometric relationship between metabolic rates and body mass (mass-scaling exponent b < 1). The origin of this pattern remains one of the most intriguing and hotly debated topics in evolutionary physiology. A decrease in mass-specific metabolic rates in larger organisms might reflect disproportionate increases in body components with low metabolic activity, such as storage and skeletal tissues. Addressing this hypothesis, we studied standard metabolic rates, body mass, and fat and exoskeletal mass in males and females from 15 species of Carabidae beetles. There was a sub-linear allometric relationship of metabolic rate with body mass: b = 0.72 (phylogeny not considered), b = 0.54 (phylogeny considered). The latter exponent was significantly lower than 0.75, which is sometimes regarded as a universal exponent value in the mass scaling of metabolic rates. Contrary to our hypothesis, the relative contribution of fat and the exoskeleton to body mass decreased, rather than increased with body mass, as indicated by the sub-linear allometric mass scaling of both components (b < 1). Supporting the role of metabolically inert body components in shaping metabolic scaling, the exponents (b) for metabolism became slightly smaller (b = 0.70, phylogeny not considered; 0.52, phylogeny considered) when we removed lipids and the exoskeleton from body mass calculations and considered only the lean mass of soft tissue in the mass scaling. Overall, our results indicate that, in beetles, the relative content of metabolically inert components changes across species according to species-specific body mass. Nevertheless, we did not find evidence that this changing contribution plays a central role in the origin of interspecific metabolic scaling in carabids. Our findings stress the need for finding alternative explanations, at least in carabids, for the origin of the mass scaling of metabolic rates.

An experimental test of the physiological consequences of avian malaria infection.

Chronic, low-intensity parasite infections can reduce host fitness through negative impacts on reproduction and survival, even if they produce few overt symptoms. As a result, these parasites can influence the evolution of host morphology, behaviour and physiology. The physiological consequences of chronic infection can provide insight into the processes underlying parasite-driven natural selection. Here, we evaluate the physiological consequences of natural, low-intensity infection in an avian host-parasite system: adult male red-winged blackbirds (Agelaius phoeniceus) infected with haemosporidian parasites. Chronic haemosporidian infection has previously been shown to reduce both reproductive success and survival in several avian species. We used antimalarial medications to experimentally reduce haemosporidian parasitaemia (the proportion of blood cells infected with haemosporidian parasites) and measured the effect of treatment on body condition, haematology, immune function, physiological stress and oxidative state. Treatment with an antimalarial medication reduced parasitaemia for the most prevalent haemosporidian parasites from the genus Plasmodium. Treatment also increased haemoglobin and haematocrit, and decreased red blood cell production rates. We detected no effect of treatment on body condition, immune metrics, plasma corticosterone concentrations, total antioxidant capacity or reactive oxygen metabolites. Our results suggest that the damage and replacement of red blood cells during infection could be important costs of chronic haemosporidian infection. Strong links between parasitaemia and the physiological consequences of infection indicate that even for relatively low-intensity infections, measuring parasitaemia rather than only presence/absence could be important when evaluating the role of infection in influencing hosts' behaviour, physiology or fitness.

Combining multiple statistical methods to evaluate the performance of process-based vegetation models across three forest stands

AbstractProcess-based vegetation models are crucial tools to better understand biosphere-atmosphere exchanges and ecophysiological responses to climate change. In this contribution the performance of two global dynamic vegetation models, i.e. CARAIB and ISBACC, and one stand-scale forest model, i.e. 4C, was compared to long-term observed net ecosystem carbon exchange (NEE) time series from eddy covariance monitoring stations at three old-grown European beech (Fagus sylvatica L.) forest stands. Residual analysis, wavelet analysis and singular spectrum analysis were used beside conventional scalar statistical measures to assess model performance with the aim of defining future targets for model improvement. We found that the most important errors for all three models occurred at the edges of the observed NEE distribution and the model errors were correlated with environmental variables on a daily scale. These observations point to possible projection issues under more extreme future climate conditions. Recurrent patterns in the residuals over the course of the year were linked to the approach to simulate phenology and physiological evolution during leaf development and senescence. Substantial model errors occurred on the multi-annual time scale, possibly caused by the lack of inclusion of management actions and disturbances. Other crucial processes defined were the forest structure and the vertical light partitioning through the canopy. Further, model errors were shown not to be transmitted from one time scale to another. We proved that models should be evaluated across multiple sites, preferably using multiple evaluation methods, to identify processes that request reconsideration.

Ecological and phylogenetic variability in the spinalis muscle of snakes.

Understanding the origin and maintenance of functionally important subordinate traits is a major goal of evolutionary physiologists and ecomorphologists. Within the confines of a limbless body plan, snakes are diverse in terms of body size and ecology, but we know little about the functional traits that underlie this diversity. We used a phylogenetically diverse group of 131 snake species to examine associations between habitat use, sidewinding locomotion and constriction behaviour with the number of body vertebrae spanned by a single segment of the spinalis muscle, with total numbers of body vertebrae used as a covariate in statistical analyses. We compared models with combinations of these predictors to determine which best fit the data among all species and for the advanced snakes only (N=114). We used both ordinary least-squares models and phylogenetic models in which the residuals were modelled as evolving by the Ornstein-Uhlenbeck process. Snakes with greater numbers of vertebrae tended to have spinalis muscles that spanned more vertebrae. Habitat effects dominated models for analyses of all species and advanced snakes only, with the spinalis length spanning more vertebrae in arboreal species and fewer vertebrae in aquatic and burrowing species. Sidewinding specialists had shorter muscle lengths than nonspecialists. The relationship between prey constriction and spinalis length was less clear. Differences among clades were also strong when considering all species, but not for advanced snakes alone. Overall, these results suggest that muscle morphology may have played a key role in the adaptive radiation of snakes.

Physiological and behavioral responses to salinity in coastal Dice snakes

Secondarily marine tetrapods have evolved adaptations to maintain their osmotic balance in a hyperosmotic environment. During the transition to a marine habitat, the evolution of a euryhaline physiology likely encompassed successive changes in behavior and physiology that released organisms from regular access to fresh water. Deciphering these key steps is a complicated task. In this study, we investigated a species of freshwater natricine snake in which some populations are known to use marine environments. We experimentally subjected 30 adult Dice snakes (Natrix tessellata) from a population inhabiting the Black Sea coast to three salinities corresponding to freshwater (~0.1‰), brackish water (~15.0‰), and full-strength seawater (~34.0‰) in order to investigate their physiological (variation of body mass, osmolality) and behavioral (activity, drinking behavior) responses to salinity. Our results show that coastal Dice snakes from the study population are relatively tolerant to salinity close to that recorded in the Black Sea, but that prolonged exposure to full-strength seawater increases osmolality, stimulates thirst, decreases the activity of snakes and may ultimately jeopardize survival. Collectively with previously published data, our results strongly suggest specific physiological adaptations to withstand hyperosmolality rather than to reduce intake of salt, in coastal populations or species of semi-aquatic snakes. Future comparative investigations of Dice snakes from populations restricted to freshwater environment might reveal the functional traits and the behavioral and physiological responses of coastal N. tessellata to life in water with elevated salinity.

Plant Evolution and Climate Over Geological Timescales

The terrestrial vegetation is unambiguously an important factor in the climate system, modulating the exchange of energy, momentum, water vapor, and other trace gases between land and atmosphere. Here, we review the evolution of the terrestrial flora from the Proterozoic through to the Neogene at three distinct scales—the overall evolution of floral composition, the evolution of plant physiology, and the evolution of landscape occupation both spatially and seasonally—all in the context of how the vegetation may have influenced climate through time and which deep-time evolutionary transitions may have had the greatest effect. Our focus is upon the direct impacts of the vegetation on temperature and precipitation, but we also consider the indirect impacts of plants on climate via atmospheric composition. We argue that the times of greatest change in plant climate feedbacks are likely to have been the Carboniferous and the early Paleogene.

Astroglial vesicular network: evolutionary trends, physiology and pathophysiology.

Intracellular organelles, including secretory vesicles, emerged when eukaryotic cells evolved some 3 billion years ago. The primordial organelles that evolved in Archaea were similar to endolysosomes, which developed, arguably, for specific metabolic tasks, including uptake, metabolic processing, storage and disposal of molecules. In comparison with prokaryotes, cell volume of eukaryotes increased by several orders of magnitude and vesicle traffic emerged to allow for communication between distant intracellular locations. Lysosomes, first described in 1955, a prominent intermediate of endo- and exocytotic pathways, operate virtually in all eukaryotic cells including astroglia, the most heterogeneous type of homeostatic glia in the central nervous system. Astrocytes support neuronal network activity in particular through elaborated secretion, based on a complex intracellular vesicle network dynamics. Deranged homeostasis underlies disease and astroglial vesicle traffic contributes to the pathophysiology of neurodegenerative (Alzheimer's disease, Huntington's disease), neurodevelopmental diseases (intellectual deficiency, Rett's disease) and neuroinfectious (Zika virus) disorders. This review addresses astroglial cell-autonomous vesicular traffic network, as well as its into primary and secondary vesicular network defects in diseases, and considers this network as a target for developing new therapies for neurological conditions.

The Evolution of Pragmatism

AbstractThe pragmatist theory of history, action, and sociality can be understood as the result of a specific interpretation of Darwin’s theory of evolution, which has nothing in common with teleological, reductionist, or social Darwinist evolutionary models. Thishistorical claimwill be developed in three steps. First, I will show why Darwin’s theory was so attractive to the classical pragmatists and how theirconception of historywas affected by their reading of Darwin. Second, I will illustrate how the pragmatist understanding ofindividual actionwas influenced by contemporary discussions in evolutionary theory, physiology, and psychology. Third, I will discuss pragmatism’s “cultural naturalism” (John Dewey), according to which a new, autonomous level ofsociocultural changeemerges as a result of the process of biological evolution. The reconstruction of pragmatist evolutionary thought not only aims to achieve a better historical understanding of pragmatism but also implies asystematic and theoretical claim. As will be argued in the last section of this paper, thetimeliness and continuing relevance of pragmatismis largely due to the fact that it took shape in a transdisciplinary context and remained an “empirically responsible” theory (Erkki Kilpinen). Currently, various innovative developments within psychology, the cognitive sciences, neurophysiology, and ethology are connected with the core insights of pragmatism, thereby supporting the argument that pragmatism is still evolving.

Perspectives on non-target site mechanisms of herbicide resistance in weedy plant species using evolutionary physiology.

Evolutionary physiology merges the disciplines of evolution and physiology, and it is a research approach that has not received much attention for studying the development of herbicide resistance. This paper makes a case for using evolutionary physiology more frequently when studying herbicide resistance, and illustrates this using three areas where more work would be useful: (i) the interaction among major and minor alleles over many generations during the evolution of physiological responses that lead to specific mechanisms of resistance; (ii) the role of epigenetic factors, especially at an early stage of evolution, on the physiological modifications that result in phenotypes that become insensitive to herbicides; and (iii) the interaction between fitness and physiological performance over time, with emphasis on understanding mechanisms that improve the fitness of herbicide-resistant phenotypes during selection.

Chemostat Culture for Yeast Physiology and Experimental Evolution.

Continuous culture provides many benefits over the classical batch style of growing yeast cells. Steady-state cultures allow for precise control of growth rate and environment. Cultures can be propagated for weeks or months in these controlled environments, which is important for the study of experimental evolution. Despite these advantages, chemostats have not become a highly used system, in large part because of their historical impracticalities, including low throughput, large footprint, systematic complexity, commercial unavailability, high cost, and insufficient protocol availability. However, we have developed methods for building a relatively simple, low-cost, small footprint array of chemostats that can be run in multiples of 32. This "ministat array" can be applied to problems in yeast physiology and experimental evolution.