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Beneficial Acclimation Hypothesis
The beneficial acclimation hypothesis (BAH) is the physiological hypothesis that acclimating to a particular environment (usually thermal) provides an organism with advantages in that environment. First formally tested by Armand Marie Leroi, Albert Bennett, and Richard Lenski in 1994, it has however been a central assumption in historical physiological work that acclimation is adaptive. Further refined by Raymond B. Huey and David Berrigan under the strong inference approach, the hypothesis has been falsified as a general rule by a series of multiple hypotheses experiments. History and definition Acclimation is a set of physiological responses that occurs during an individual's lifetime to chronic laboratory-induced environmental conditions (in contrast to acclimatization). It is one component of adaptation. While physiologists have traditionally assumed that acclimation is beneficial (or explicitly defined it as such), criticism of the adaptationist program by Stephe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physiology
Physiology (; ) is the science, scientific study of function (biology), functions and mechanism (biology), mechanisms in a life, living system. As a branches of science, subdiscipline of biology, physiology focuses on how organisms, organ systems, individual organ (biology), organs, cell (biology), cells, and biomolecules carry out chemistry, chemical and physics, physical functions in a living system. According to the classes of organisms, the field can be divided into clinical physiology, medical physiology, Zoology#Physiology, animal physiology, plant physiology, cell physiology, and comparative physiology. Central to physiological functioning are biophysics, biophysical and biochemical processes, homeostasis, homeostatic control mechanisms, and cell signaling, communication between cells. ''Physiological state'' is the condition of normal function. In contrast, ''pathology, pathological state'' refers to abnormality (behavior), abnormal conditions, including human diseases. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Krogh's Principle
Krogh's principle states that "for such a large number of problems there will be some animal of choice, or a few such animals, on which it can be most conveniently studied." This concept is central to those disciplines of biology that rely on the comparative method, such as neuroethology, comparative physiology, and more recently functional genomics. History Krogh's principle is named after the Danish physiologist August Krogh, winner of the Nobel Prize in Physiology for his contributions to understanding the anatomy and physiology of the capillary system, who described it in The American Journal of Physiology in 1929. However, the principle was first elucidated nearly 60 years prior to this, and in almost the same words as Krogh, in 1865 by Claude Bernard, the French instigator of experimental medicine, on page 27 of his "Introduction à l'étude de la médecine expérimentale": Krogh wrote the following in his 1929 treatise on the then current 'status' of physiology (emphasis a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fitness (biology)
Fitness (often denoted w or ω in population genetics models) is a quantitative representation of individual reproductive success. It is also equal to the average contribution to the gene pool of the next generation, made by the same individuals of the specified genotype or phenotype. Fitness can be defined either with respect to a genotype or to a phenotype in a given environment or time. The fitness of a genotype is manifested through its phenotype, which is also affected by the developmental environment. The fitness of a given phenotype can also be different in different selective environments. With asexual reproduction, it is sufficient to assign fitnesses to genotypes. With sexual reproduction, recombination scrambles alleles into different genotypes every generation; in this case, fitness values can be assigned to alleles by averaging over possible genetic backgrounds. Natural selection tends to make alleles with higher fitness more common over time, resulting in Darwini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolutionary Physiology
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. Accordingly, the range of phenotypes studied by evolutionary physiologists is broad, including life history traits, behavior, whole-organism performance, functional morphology, biomechanics, anatomy, classical physiology, endocrinology, biochemistry, and molecular evolution. The field is closely related to comparative physiology, ecophysiology, and environmental physiology, and its findings are a major concern of evolutionary medicine. One def ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecophysiology
Ecophysiology (from Greek , ''oikos'', "house(hold)"; , ''physis'', "nature, origin"; and , '' -logia''), environmental physiology or physiological ecology is a biological discipline that studies the response of an organism's physiology to environmental conditions. It is closely related to comparative physiology and evolutionary physiology. Ernst Haeckel's coinage bionomy is sometimes employed as a synonym. Plants Plant ecophysiology is concerned largely with two topics: mechanisms (how plants sense and respond to environmental change) and scaling or integration (how the responses to highly variable conditions—for example, gradients from full sunlight to 95% shade within tree canopies—are coordinated with one another), and how their collective effect on plant growth and gas exchange can be understood on this basis. In many cases, animals are able to escape unfavourable and changing environmental factors such as heat, cold, drought or floods, while plants are unable to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acclimatisation
Acclimatization or acclimatisation ( also called acclimation or acclimatation) is the process in which an individual organism adjusts to a change in its environment (such as a change in altitude, temperature, humidity, photoperiod, or pH), allowing it to maintain fitness across a range of environmental conditions. Acclimatization occurs in a short period of time (hours to weeks), and within the organism's lifetime (compared to adaptation, which is evolution, taking place over many generations). This may be a discrete occurrence (for example, when mountaineers acclimate to high altitude over hours or days) 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, researc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenotypic Plasticity
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 (e.g. morphological, physiological, behavioural, phenological) that may or may not be permanent throughout an individual's lifespan. The term was originally used to describe developmental effects on morphological characters, but is now more broadly used to describe all phenotypic responses to environmental change, such as acclimation (acclimatization), as well as learning. The special case when differences in environment induce discrete phenotypes is termed polyphenism. Generally, phenotypic plasticity is more important for immobile organisms (e.g. plants) than mobile organisms (e.g. most animals), as mobile organisms can often move away from unfavourable environments. Nevertheless ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Life Cycle
In biology, a biological life cycle (or just life cycle when the biological context is clear) is a series of stages of the life of an organism, that begins as a zygote, often in an egg, and concludes as an adult that reproduces, producing an offspring in the form of a new zygote which then itself goes through the same series of stages, the process repeating in a cyclic fashion. "The concept is closely related to those of the life history, Developmental biology, development and ontogeny, but differs from them in stressing renewal." Transitions of form may involve growth, asexual reproduction, or sexual reproduction. In some organisms, different "generations" of the species succeed each other during the life cycle. For Embryophyte, plants and many algae, there are two multicellular stages, and the life cycle is referred to as alternation of generations. The term life history is often used, particularly for organisms such as the red algae which have three multicellular stages (or mor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fertility
Fertility in colloquial terms refers the ability to have offspring. In demographic contexts, fertility refers to the actual production of offspring, rather than the physical capability to reproduce, which is termed fecundity. The fertility rate is the average number of children born during an individual's lifetime. In medicine, fertility refers to the ability to have children, and infertility refers to difficulty in reproducing naturally. In general, infertility or subfertility in humans is defined as not being able to conceive a child after one year (or longer) of unprotected sex. The antithesis of ''fertility'' is infertility, while the antithesis of ''fecundity'' is sterility. Demography In demographic contexts, fertility refers to the actual production of offspring, rather than the physical capability to produce which is termed fecundity. While fertility can be measured, fecundity cannot be. Demographers measure the fertility rate in a variety of ways, which can be broa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Longevity
Longevity may refer to especially long-lived members of a population, whereas ''life expectancy'' is defined Statistics, statistically as the average number of years remaining at a given age. For example, a population's life expectancy at birth is the same as the average age at death for all people born in the same year (in the case of Cohort (statistics), cohorts). Longevity studies may involve putative methods to extend life. Longevity has been a topic not only for the scientific community but also for writers of Hyperborei, travel, science fiction, and utopian novels. The legendary fountain of youth appeared in the work of the Ancient Greek historian Herodotus. There are difficulties in authenticating the longest human maximum life span, life span, owing to inaccurate or incomplete birth statistics. Fiction, legend, and folklore have proposed or claimed life spans in the past or future vastly longer than those verified by modern standards, and longevity narratives and unverif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genes
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and non-coding genes. During gene expression (the synthesis of Gene product, RNA or protein from a gene), DNA is first transcription (biology), copied into RNA. RNA can be non-coding RNA, directly functional or be the intermediate protein biosynthesis, template for the synthesis of a protein. The transmission of genes to an organism's offspring, is the basis of the inheritance of phenotypic traits from one generation to the next. These genes make up different DNA sequences, together called a genotype, that is specific to every given individual, within the gene pool of the population (biology), population of a given species. The genotype, along with environmental and developmental factors, ultimately determines the phenotype ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Migration
Migration, migratory, or migrate may refer to: Human migration * Human migration, physical movement by humans from one region to another ** International migration, when peoples cross state boundaries and stay in the host state for some minimum length of time Natural sciences Biology * Migration (ecology), the large-scale movement of species from one environment to another ** Animal migration ** Bird migration * Plant migration, see Seed dispersal, the movement or transport of seeds away from the parent plant * Gene migration, a process in evolution and population genetics * Cell migration, a process in the development and maintenance of multicellular organisms ** Collective cell migration, describing the movements of group of cells Physics and chemistry * Molecular diffusion, in physics * Migration (chemistry), type of reaction in organic chemistry * Seismic migration, in seismic and ground penetrating radar data processing * Microscopic motion of material caused by an exte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
