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Variational Properties
In evolutionary biology, the variational properties of an organism are those properties relating to the production of variation among its offspring. In a broader sense variational properties include phenotypic plasticity. Wagner, G. P. and Altenberg, L. 1996. Complex adaptations and the evolution of evolvability. ''Evolution'' 50 (3): 967-976. Variational properties contrast with functional properties. While the functional properties of an organism determine is level of adaptedness to its environment, it is the variational properties of the organisms in a species that chiefly determine its evolvability and genetic robustness. Variational properties group together many classical and more recent concepts of evolutionary biology. It includes the classical concepts of pleiotropy, canalization, developmental constraints, developmental bias, morphological integration, developmental homeostasis and later concepts such as robustness, neutral networks, modularity, the G-matrix and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lee Altenberg
Lee Altenberg is an American theoretical biologist. He is on the faculty of the Departments of Information and Computer Sciences and of Mathematics at the University of Hawaii at Mānoa. He is best known for his work that helped establish the evolution of evolvability and modularity in the genotype–phenotype map as areas of investigation in evolutionary biology, for moving theoretical concepts between the fields of evolutionary biology and evolutionary computation, and for his mathematical unification and generalization of modifier gene models for the evolution of biological information transmission, putting under a single mathematical framework the evolution of mutation rates, recombination rates, sexual reproduction rates, and dispersal rates. Altenberg is an Associate Editor of the journal ''BioSystems'', and serves on the Editorial Boards of the journals '' Genetic Programming and Evolvable Machines'' and ''Artificial Life'', and on the IEEE Computational Intelligence Soc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Günter P
Gunter or Günter may refer to: * Gunter rig, a type of rig used in sailing, especially in small boats * Gunter Annex, Alabama, a United States Air Force installation * Gunter, Texas, city in the United States People Surname * Chris Gunter (born 1989), Welsh footballer with Cardiff City, Tottenham Hotspur, Nottingham Forest and Reading * Cornell Gunter (1936–1990), American R&B singer, brother of Shirley Gunter * David Gunter (1933–2005), English footballer with Southampton, brother of Phil Gunter * Edmund Gunter (1581–1626), British mathematician and inventor, known for: ** Gunter's chain ** Gunter's rule * James Gunter (1745–1819), English confectioner, fruit grower and scientific gardener * Jen Gunter (born 1966), Canadian-American gynecologist & author * Gordon Gunter (1909–1998), American marine biologist and fisheries scientist * Matthew Alan Gunter (born 1957), United States Episcopal bishop * Phil Gunter (1932–2007), English footballer with Portsmouth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adaptation
In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the population during that process. Thirdly, it is a phenotypic trait or adaptive trait, with a functional role in each individual organism, that is maintained and has evolved through natural selection. Historically, adaptation has been described from the time of the ancient Greek philosophers such as Empedocles and Aristotle. In 18th and 19th century natural theology, adaptation was taken as evidence for the existence of a deity. Charles Darwin proposed instead that it was explained by natural selection. Adaptation is related to biological fitness, which governs the rate of evolution as measured by change in allele frequencies. Often, two or more species co-adapt and co-evolve as they develop adaptations that interlock with those of the oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolvability
Evolvability is defined as the capacity of a system for adaptive evolution. Evolvability is the ability of a population of organisms to not merely generate genetic diversity, but to generate ''adaptive'' genetic diversity, and thereby evolve through natural selection. In order for a biological organism to evolve by natural selection, there must be a certain minimum probability that new, heritable variants are beneficial. Random mutations, unless they occur in DNA sequences with no function, are expected to be mostly detrimental. Beneficial mutations are always rare, but if they are too rare, then adaptation cannot occur. Early failed efforts to evolve computer programs by random mutation and selection showed that evolvability is not a given, but depends on the representation of the program as a data structure, because this determines how changes in the program map to changes in its behavior. Analogously, the evolvability of organisms depends on their genotype–phenotype map. Thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Robustness
In evolutionary biology, robustness of a biological system (also called biological or genetic robustness) is the persistence of a certain characteristic or trait in a system under perturbations or conditions of uncertainty. Robustness in development is known as canalization. According to the kind of perturbation involved, robustness can be classified as mutational, environmental, recombinational, or behavioral robustness ''etc''. Robustness is achieved through the combination of many genetic and molecular mechanisms and can evolve by either direct or indirect selection. Several model systems have been developed to experimentally study robustness and its evolutionary consequences. Classification Mutational robustness Mutational robustness (also called mutation tolerance) describes the extent to which an organism’s phenotype remains constant in spite of mutation. Robustness can be empirically measured for several genomes and individual genes by inducing mutations and meas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleiotropy
Pleiotropy (from Greek , 'more', and , 'way') occurs when one gene influences two or more seemingly unrelated phenotypic traits. Such a gene that exhibits multiple phenotypic expression is called a pleiotropic gene. Mutation in a pleiotropic gene may have an effect on several traits simultaneously, due to the gene coding for a product used by a myriad of cells or different targets that have the same signaling function. Pleiotropy can arise from several distinct but potentially overlapping mechanisms, such as gene pleiotropy, developmental pleiotropy, and selectional pleiotropy. Gene pleiotropy occurs when a gene product interacts with multiple other proteins or catalyzes multiple reactions. Developmental pleiotropy occurs when mutations have multiple effects on the resulting phenotype. Selectional pleiotropy occurs when the resulting phenotype has many effects on fitness (depending on factors such as age and gender). An example of pleiotropy is phenylketonuria, an inherited d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canalization (genetics)
Canalisation is a measure of the ability of a population to produce the same phenotype regardless of variability of its environment or genotype. It is a form of evolutionary robustness. The term was coined in 1942 by C. H. Waddington to capture the fact that "developmental reactions, as they occur in organisms submitted to natural selection...are adjusted so as to bring about one definite end-result regardless of minor variations in conditions during the course of the reaction". He used this word rather than robustness to take into account that biological systems are not robust in quite the same way as, for example, engineered systems. Biological robustness or canalisation comes about when developmental pathways are shaped by evolution. Waddington introduced the concept of the epigenetic landscape, in which the state of an organism rolls "downhill" during development. In this metaphor, a canalised trait is illustrated as a valley (which he called a creode) enclosed by hig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Developmental Constraints
Development of the human body is the process of growth to maturity. The process begins with fertilization, where an egg released from the ovary of a female is penetrated by a sperm cell from a male. The resulting zygote develops through mitosis and cell differentiation, and the resulting embryo then implants in the uterus, where the embryo continues development through a fetal stage until birth. Further growth and development continues after birth, and includes both physical and psychological development, influenced by genetic, hormonal, environmental and other factors. This continues throughout life: through childhood and adolescence into adulthood. Before birth Development before birth, or prenatal development () is the process in which a zygote, and later an embryo and then a fetus develops during gestation. Prenatal development starts with fertilization and the formation of the zygote, the first stage in embryonic development which continues in fetal development unt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Developmental Bias
Development of the human body is the process of growth to maturity. The process begins with fertilization, where an egg released from the ovary of a female is penetrated by a sperm cell from a male. The resulting zygote develops through mitosis and cell differentiation, and the resulting embryo then implants in the uterus, where the embryo continues development through a fetal stage until birth. Further growth and development continues after birth, and includes both physical and psychological development, influenced by genetic, hormonal, environmental and other factors. This continues throughout life: through childhood and adolescence into adulthood. Before birth Development before birth, or prenatal development () is the process in which a zygote, and later an embryo and then a fetus develops during gestation. Prenatal development starts with fertilization and the formation of the zygote, the first stage in embryonic development which continues in fetal development until b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morphological Integration
Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines * Morphology (archaeology), study of the shapes or forms of artifacts *Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, or other extended objects *Morphology (biology), the study of the form or shape of an organism or part thereof * Morphology (folkloristics), the structure of narratives such as folk tales *Morphology (linguistics), the study of the structure and content of word forms *Mathematical morphology, a theoretical model based on lattice theory, used for digital image processing *River morphology, the field of science dealing with changes of river platform * Urban morphology, study of the form, structure, formation and transformation of human settlements *Geomorphology, the study of landforms *Morphology (architecture and engineering), research which is based on theories of two-dimensional and three-dimensional symmetries, and then uses these geome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Developmental Homeostasis
Developmental homeostasis is a process in which animals develop more or less normally, despite defective genes and deficient environments. It is an organisms ability to overcome certain circumstances in order to develop normally. This can be either a physical or mental circumstance that interferes with either a physical or mental trait. Many species have a specific norm, where those who fit that norm prosper while those who don't are killed or find it difficult to thrive. It is important that the animal be able to interact with the other group members effectively. Animals must learn their species' norms early to live a normal, successful life for that species. Developmental homeostasis determines how a species adapts to live a normal life. Therefore, it has been the focus of many experiments. These experiments are geared and designed to test the threshold for certain species to overcome and prosper despite certain circumstances. Due to the fact that survival of the species is based ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robustness (evolution)
In evolutionary biology, robustness of a biological system (also called biological or genetic robustness) is the persistence of a certain characteristic or trait in a system under perturbations or conditions of uncertainty. Robustness in development is known as canalization. According to the kind of perturbation involved, robustness can be classified as mutational, environmental, recombinational, or behavioral robustness ''etc''. Robustness is achieved through the combination of many genetic and molecular mechanisms and can evolve by either direct or indirect selection. Several model systems have been developed to experimentally study robustness and its evolutionary consequences. Classification Mutational robustness Mutational robustness (also called mutation tolerance) describes the extent to which an organism’s phenotype remains constant in spite of mutation. Robustness can be empirically measured for several genomes and individual genes by inducing mutations and measu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
