More than Breathing Air: Evolutionary Drivers and Physiological Implications of an Amphibious Lifestyle in Fishes

Amphibious and aquatic air-breathing fishes both exchange respiratory gasses with the atmosphere, but these fishes differ in physiology, ecology, and possibly evolutionary origins. We introduce a scoring system to characterize interspecific variation in amphibiousness and use this system to highlight important unanswered questions about the evolutionary physiology of amphibious fishes.

Physiological insight into the evolution of complex phenotypes: aerobic performance and the O2 transport pathway of vertebrates

ABSTRACT Evolutionary physiology strives to understand how the function and integration of physiological systems influence the way in which organisms evolve. Studies of the O2 transport pathway – the integrated physiological system that transports O2 from the environment to mitochondria – are well suited to this endeavour. We consider the mechanistic underpinnings across the O2 pathway for the evolution of aerobic capacity, focusing on studies of artificial selection and naturally selected divergence among wild populations of mammals and fish. We show that evolved changes in aerobic capacity do not require concerted changes across the O2 pathway and can arise quickly from changes in one or a subset of pathway steps. Population divergence in aerobic capacity can be associated with the evolution of plasticity in response to environmental variation or activity. In some cases, initial evolutionary divergence of aerobic capacity arose exclusively from increased capacities for O2 diffusion and/or utilization in active O2-consuming tissues (muscle), which may often constitute first steps in adaptation. However, continued selection leading to greater divergence in aerobic capacity is often associated with increased capacities for circulatory and pulmonary O2 transport. Increases in tissue O2 diffusing capacity may augment the adaptive benefit of increasing circulatory O2 transport owing to their interactive influence on tissue O2 extraction. Theoretical modelling of the O2 pathway suggests that O2 pathway steps with a disproportionately large influence over aerobic capacity have been more likely to evolve, but more work is needed to appreciate the extent to which such physiological principles can predict evolutionary outcomes.

Evaluating tank acclimation and trial length for dynamic shuttle box temperature preference assays in aquatic animals

Characterizing the thermal preference of fish is important in conservation, environmental and evolutionary physiology and can be determined using a shuttle box system. Initial tank acclimation and trial lengths are important considerations in experimental design, yet systematic studies of these factors are missing. Three different behavioral assay experimental designs were tested to determine the effect of tank acclimation and trial length (12:12, 0:12, 2:2; hours of tank acclimation: behavioral trial) on the temperature preference of juvenile lake whitefish (Coregonus clupeaformis), using a shuttle box. Average temperature preferences for the 12:12, 0:12, and 2:2 experimental designs were 16.10±1.07°C, 16.02±1.56°C, 16.12±1.59°C respectively, with no significant differences between experimental designs (p= 0.9337). Ultimately, length of acclimation time and trial length had no significant effect on thermal preference.

НАСЛЕДИЕ АКАДЕМИКА Л.А. ОРБЕЛИ: ИНСТИТУТУ ЭВОЛЮЦИОННОЙ ФИЗИОЛОГИИ И БИОХИМИИ ИМ. И.М. СЕЧЕНОВА РАН 65 ЛЕТ

The history of I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry is reviewed with emphasis on continuity in the activities of its directors starting from academician Leon Abgarovich Orbeli, the founder and the first director thereof.

Defining Comparative Physiology: Results from an Online Survey and Systematic Review

August Krogh's 1929 principle is referenced as the cornerstone of comparative physiology (CP). However, there are diverse views as to what type of research falls under the CP approach. This study had three aims: 1) determine how CP is defined through an online survey (OS) of physiologists and a systematic review (SR), 2) put forth an updated definition of CP by summarizing OS and SR results, and 3) outline the numerous CP research approaches. Professional physiology societies (n=54) were invited to share the OS with their members and a SR was conducted which yielded 197 and 70 definitions, respectively. The three most common words in descending order in the OS definitions were 'different', 'animals', and 'species' and in the SR definitions, 'animals', 'species', and 'organisms'. The three most prevalent themes from the OS and SR definitions were comparing/differences/diversity across species (78% and 51%, respectively), response to the environment/ecology (28% and 43%, respectively), and included evolution or adaptation (24% and 60%, respectively). Ten research approaches were identified, which include: broad comparison (i.e., many species generalization), specific comparison (e.g., two species; for traits that are different, exaggerated, extreme, missing, or not induced), or comparison while considering evolution (i.e., evolutionary physiology), ecology (i.e., ecophysiology), or human physiology/medicine. Only 5% and 33% of OS and SR definitions described or mentioned Krogh's principle. In conclusion, CP can best be defined as a compilation of research approaches that utilize different types of comparisons to elucidate physiological mechanisms, and not simply comparing physiologies as the name implies.

The Making and Development of E. N. Mirzoyan’s Evolutionary Concept (In Commemoration of the 90 th Anniversary of His Birth)

A renowned biologist and historian of science Eduard Nikolaevich Mirzoyan would have turned 90 in April 2021. The author of over 200 publications, including 15 monographs, on the history of evolutionary morphology, evolutionary histology, evolutionary physiology and biochemistry, and evolutionary and global ecology, he was also exploring the problem of how ontogenesis and phylogenesis are related to the theoretical aspects of evolutionary biology. As a result of a long-time creative pursuit, Mirzoyan developed his own outlook on biological evolution, captured mostly in his personal archive. Analyzing the 20 th century evolutionary synthesis strategies, Mirzoyan formulated his own evolutionary concept and put forward an idea that the 21 st century evolutionists must concentrate their efforts on constructing a general theory of the living matter evolution instead of the evolutionary theories that prevailed in the 20 th century and focused on explaining the formation of species. This article is devoted to the analysis of Mizoyan’s evolutionary views.

Urban Evolutionary Physiology

Organisms living in urban environments are exposed to many novel, sometimes beneficial, but most often challenging conditions. These conditions include increased exposure to chemical pollution, artificial light at night, noise, altered pathogen and predator communities, increased abundance of often poor quality food, increased temperature, and increased human presence and disturbances. Given the central role of a variety of physiological responses in coping with challenges such as these, the authors of the chapter expect that the range of physiological phenotypes expressed by individuals and species will dramatically influence their ability to persist in urban habitat and cope with urban challenges. They also expect that plasticity in components of these physiological systems will be an important target of selection imposed by the challenges confronting urban populations. The chapter takes a closer look at three fundamental physiological systems in animals that are central components of coping responses to environmental challenges, namely detoxification, and endocrine and metabolic systems.