Organismal performance (or whole-organism performance) refers to the ability of an organism to conduct a task when maximally motivated. [1] Various aspects of performance are of primary concern in human athletics, horse racing, and dog racing. Performance in swimming tasks has been a subject of fisheries research since the 1960s. [2] In a broader biological context, the term first came to prominence with studies of locomotor abilities in lizards and snakes in the late 1970s and early 1980s. [3]
A seminal paper by Stevan J. Arnold in 1983 [4] focused on the importance of performance as an intermediary between lower-level traits and how natural selection acts. In particular, selection should act more directly on performance than on the subordinate traits (e.g., aspects of morphology, physiology, neurobiology) that determine performance abilities. In other words, how fast a lizard can run is more important in escaping from predators than are the lengths of its legs, because they only party determine its ability to run fast. Since then, others have pointed out that behavior often acts as a "filter" between selection and performance [5] [6] [7] because animals do not always behave in ways that use their maximal performance abilities. [8] For example, if a lizard that saw a predator approaching did not choose to run, then its ability to sprint would be irrelevant. In any case, the original version of the conceptual model has stimulated much research in integrative organismal biology. [9] However, contrary to the hypothesis that selection should be stronger on whole-organism functional performance traits (such as sprinting ability) than on correlated morphological traits, a review of empirical studies did not find evidence that selection measured in the wild was stronger on performance. [10]
Although organismal performance is more commonly studied in animals (including human beings) than in plants, various studies have focused on whole-plant performance in a similar vein. [11] For example, suction feeding abilities have been measured in carnivorous plants (bladderworts). [12] Although plants do not have either a nervous system or muscles, they can be said to have behavior. [13] [14] How such "behavior" may serve as a filter between performance and selection apparently has not been studied.
Ontogeny is the origination and development of an organism, usually from the time of fertilization of the egg to adult. The term can also be used to refer to the study of the entirety of an organism's lifespan.
Physiology is the scientific study of functions and mechanisms in a living system. As a subdiscipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out chemical and physical functions in a living system. According to the classes of organisms, the field can be divided into medical physiology, animal physiology, plant physiology, cell physiology, and comparative physiology.
In genetics, the phenotype is the set of observable characteristics or traits of an organism. The term covers the organism's morphology, its developmental processes, its biochemical and physiological properties, its behavior, and the products of behavior. An organism's phenotype results from two basic factors: the expression of an organism's genetic code and the influence of environmental factors. Both factors may interact, further affecting the phenotype. When two or more clearly different phenotypes exist in the same population of a species, the species is called polymorphic. A well-documented example of polymorphism is Labrador Retriever coloring; while the coat color depends on many genes, it is clearly seen in the environment as yellow, black, and brown. Richard Dawkins in 1978 and then again in his 1982 book The Extended Phenotype suggested that one can regard bird nests and other built structures such as caddisfly larva cases and beaver dams as "extended phenotypes".
Anolis is a genus of anoles, iguanian lizards in the family Dactyloidae, native to the Americas. With more than 425 species, it represents the world's most species-rich amniote tetrapod genus, although many of these have been proposed to be moved to other genera, in which case only about 45 Anolis species remain. Previously, it was classified under the family Polychrotidae that contained all the anoles, as well as Polychrus, but recent studies place it in the Dactyloidae.
Acclimatization or acclimatisation is the process in which an individual organism adjusts to a change in its environment, allowing it to maintain fitness across a range of environmental conditions. Acclimatization occurs in a short period of time, and within the organism's lifetime. This may be a discrete occurrence or may instead represent part of a periodic cycle, such as a mammal shedding heavy winter fur in favor of a lighter summer coat. Organisms can adjust their morphological, behavioral, physical, and/or biochemical traits in response to changes in their environment. While the capacity to acclimate to novel environments has been well documented in thousands of species, researchers still know very little about how and why organisms acclimate the way that they do.
Experimental evolution is the use of laboratory experiments or controlled field manipulations to explore evolutionary dynamics. Evolution may be observed in the laboratory as individuals/populations adapt to new environmental conditions by natural selection.
The common collared lizard, also commonly called eastern collared lizard, Oklahoma collared lizard, yellow-headed collared lizard, and collared lizard, is a North American species of lizard in the family Crotaphytidae. The common name "collared lizard" comes from the lizard's distinct coloration, which includes bands of black around the neck and shoulders that look like a collar. Males can be very colorful, with blue green bodies, yellow stripes on the tail and back, and yellow orange throats. There are five recognized subspecies.
Phenotypic plasticity refers to some of the changes in an organism's behavior, morphology and physiology in response to a unique environment. Fundamental to the way in which organisms cope with environmental variation, phenotypic plasticity encompasses all types of environmentally induced changes that may or may not be permanent throughout an individual's lifespan.
Comparative physiology is a subdiscipline of physiology that studies and exploits the diversity of functional characteristics of various kinds of organisms. It is closely related to evolutionary physiology and environmental physiology. Many universities offer undergraduate courses that cover comparative aspects of animal physiology. According to Clifford Ladd Prosser, "Comparative Physiology is not so much a defined discipline as a viewpoint, a philosophy."
Evolutionary physiology is the study of the biological evolution of physiological structures and processes; that is, the manner in which the functional characteristics of organisms have responded to natural selection or sexual selection or changed by random genetic drift across multiple generations during the history of a population or species. It is a sub-discipline of both physiology and evolutionary biology. Practitioners in the field come from a variety of backgrounds, including physiology, evolutionary biology, ecology, and genetics.
Phylogenetic comparative methods (PCMs) use information on the historical relationships of lineages (phylogenies) to test evolutionary hypotheses. The comparative method has a long history in evolutionary biology; indeed, Charles Darwin used differences and similarities between species as a major source of evidence in The Origin of Species. However, the fact that closely related lineages share many traits and trait combinations as a result of the process of descent with modification means that lineages are not independent. This realization inspired the development of explicitly phylogenetic comparative methods. Initially, these methods were primarily developed to control for phylogenetic history when testing for adaptation; however, in recent years the use of the term has broadened to include any use of phylogenies in statistical tests. Although most studies that employ PCMs focus on extant organisms, many methods can also be applied to extinct taxa and can incorporate information from the fossil record.
Ecological and Evolutionary Physiology is a peer-reviewed scientific journal published by the University of Chicago Press on behalf of the Society for Integrative and Comparative Biology. The journal publishes original research examining fundamental questions about how the ecological environment and/or evolutionary history interact with physiological function, as well as the ways physiology may constrain behavior. For EEP, physiology denotes the study of function in the broadest sense, across levels of organization from molecules to morphology to organismal performance and on behavior and life history traits.
Theodore Garland Jr. is a biologist specializing in evolutionary physiology at the University of California, Riverside.
Ecoimmunology or Ecological Immunology is the study of the causes and consequences of variation in immunity. The field of ecoimmunology seeks to give an ultimate perspective for proximate mechanisms of immunology. This approach places immunology in evolutionary and ecological contexts across all levels of biological organization.
Allometric engineering is the process of experimentally shifting the scaling relationships, for body size or shape, in a population of organisms. More specifically, the process of experimentally breaking the tight covariance evident among component traits of a complex phenotype by altering the variance of one trait relative to another. Typically, body size is one of the two traits. The measurements of the two traits are plotted against each other and the scaling relationship can be represented as: . Manipulations of this sort alter the scaling relationships either by shifting the intercept (b), slope (m) or both to create novel variants (see: Allometry, for more details). These novel variants can then be tested for differences in performance or fitness. Through careful testing, one could sequentially test each component of a trait suite to determine how each part contributes to the function of the entire complex phenotype, and ultimately the fitness of the organism. This technique allows for comparison within or among biological groups differing in size by adjusting morphology to match one another and comparing their performances.
Homotherini (Machairodontini) is a tribe of saber-toothed cats of the family Felidae. The tribe is commonly known as scimitar-toothed cats. These saber-toothed cats were endemic to North America, Europe, Asia, Africa, and South America from the Miocene to Pleistocene living from c. 23 Ma until c. 12,000 years ago. The evolutionary relationship between the tribes Homotherini and Machairodontini cause paleontologists to classify Homotherini either as a subtribe of Machairodontini, or the same tribe often using either name interchangeably.
Lizards are among the most diverse groups of reptiles, with more than 5,600 species. With such diversity in physical and behavioral traits, lizards have evolved many ways to communicate. Communication may be physical, chemical, tactile, or vocal, and varies according to habitat, sexual selection practices, and predator avoidance methods. Each type of communication uses different sensory systems, including visual, olfactory, and auditory.
The study of animal locomotion is a branch of biology that investigates and quantifies how animals move.
Lauren B. Buckley is an evolutionary ecologist and professor of biology at the University of Washington. She researches the relationship between organismal physiological and life history features and response to global climate change.
Albert Farrell Bennett is an American zoologist, physiologist, evolutionary biologist, author, and academic. He is Dean Emeritus of the School of Biological Sciences at University of California, Irvine.