Selection, Genetic: Differential and non-random reproduction of different genotypes, operating to alter the gene frequencies within a population.Models, Genetic: Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.Evolution, Molecular: The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.Biological Evolution: The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.Genetic Variation: Genotypic differences observed among individuals in a population.Selection Bias: The introduction of error due to systematic differences in the characteristics between those selected and those not selected for a given study. In sampling bias, error is the result of failure to ensure that all members of the reference population have a known chance of selection in the sample.Patient Selection: Criteria and standards used for the determination of the appropriateness of the inclusion of patients with specific conditions in proposed treatment plans and the criteria used for the inclusion of subjects in various clinical trials and other research protocols.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Genetics, Population: The discipline studying genetic composition of populations and effects of factors such as GENETIC SELECTION, population size, MUTATION, migration, and GENETIC DRIFT on the frequencies of various GENOTYPES and PHENOTYPES using a variety of GENETIC TECHNIQUES.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Mating Preference, Animal: The selection or choice of sexual partner in animals. Often this reproductive preference is based on traits in the potential mate, such as coloration, size, or behavioral boldness. If the chosen ones are genetically different from the rejected ones, then NATURAL SELECTION is occurring.Alleles: Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.Genetic Drift: The fluctuation of the ALLELE FREQUENCY from one generation to the next.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.Adaptation, Biological: Changes in biological features that help an organism cope with its ENVIRONMENT. These changes include physiological (ADAPTATION, PHYSIOLOGICAL), phenotypic and genetic changes.Inbreeding: The mating of plants or non-human animals which are closely related genetically.Reproduction: The total process by which organisms produce offspring. (Stedman, 25th ed)Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Computer Simulation: Computer-based representation of physical systems and phenomena such as chemical processes.Thymus Gland: A single, unpaired primary lymphoid organ situated in the MEDIASTINUM, extending superiorly into the neck to the lower edge of the THYROID GLAND and inferiorly to the fourth costal cartilage. It is necessary for normal development of immunologic function early in life. By puberty, it begins to involute and much of the tissue is replaced by fat.Sexual Behavior, Animal: Sexual activities of animals.Likelihood Functions: Functions constructed from a statistical model and a set of observed data which give the probability of that data for various values of the unknown model parameters. Those parameter values that maximize the probability are the maximum likelihood estimates of the parameters.Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.Gene Frequency: The proportion of one particular in the total of all ALLELES for one genetic locus in a breeding POPULATION.Genotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.Sex Preselection: Methods for controlling genetic SEX of offspring.Recombination, Genetic: Production of new arrangements of DNA by various mechanisms such as assortment and segregation, CROSSING OVER; GENE CONVERSION; GENETIC TRANSFORMATION; GENETIC CONJUGATION; GENETIC TRANSDUCTION; or mixed infection of viruses.Polymorphism, Genetic: The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.Genetic Fitness: The capability of an organism to survive and reproduce. The phenotypic expression of the genotype in a particular environment determines how genetically fit an organism will be.Codon: A set of three nucleotides in a protein coding sequence that specifies individual amino acids or a termination signal (CODON, TERMINATOR). Most codons are universal, but some organisms do not produce the transfer RNAs (RNA, TRANSFER) complementary to all codons. These codons are referred to as unassigned codons (CODONS, NONSENSE).Peptide Library: A collection of cloned peptides, or chemically synthesized peptides, frequently consisting of all possible combinations of amino acids making up an n-amino acid peptide.Crosses, Genetic: Deliberate breeding of two different individuals that results in offspring that carry part of the genetic material of each parent. The parent organisms must be genetically compatible and may be from different varieties or closely related species.Quantitative Trait, Heritable: A characteristic showing quantitative inheritance such as SKIN PIGMENTATION in humans. (From A Dictionary of Genetics, 4th ed)Genetic Markers: A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.Bayes Theorem: A theorem in probability theory named for Thomas Bayes (1702-1761). In epidemiology, it is used to obtain the probability of disease in a group of people with some characteristic on the basis of the overall rate of that disease and of the likelihood of that characteristic in healthy and diseased individuals. The most familiar application is in clinical decision analysis where it is used for estimating the probability of a particular diagnosis given the appearance of some symptoms or test result.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Models, Statistical: Statistical formulations or analyses which, when applied to data and found to fit the data, are then used to verify the assumptions and parameters used in the analysis. Examples of statistical models are the linear model, binomial model, polynomial model, two-parameter model, etc.Directed Molecular Evolution: The techniques used to produce molecules exhibiting properties that conform to the demands of the experimenter. These techniques combine methods of generating structural changes with methods of selection. They are also used to examine proposed mechanisms of evolution under in vitro selection conditions.Sequence Alignment: The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.Genome: The genetic complement of an organism, including all of its GENES, as represented in its DNA, or in some cases, its RNA.Haplotypes: The genetic constitution of individuals with respect to one member of a pair of allelic genes, or sets of genes that are closely linked and tend to be inherited together such as those of the MAJOR HISTOCOMPATIBILITY COMPLEX.Adaptation, Physiological: The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.SELEX Aptamer Technique: A method of generating a large library of randomized nucleotides and selecting NUCLEOTIDE APTAMERS by iterative rounds of in vitro selection. A modified procedure substitutes AMINO ACIDS in place of NUCLEOTIDES to make PEPTIDE APTAMERS.Polymorphism, Single Nucleotide: A single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.Linkage Disequilibrium: Nonrandom association of linked genes. This is the tendency of the alleles of two separate but already linked loci to be found together more frequently than would be expected by chance alone.Quantitative Trait Loci: Genetic loci associated with a QUANTITATIVE TRAIT.Chromosome Mapping: Any method used for determining the location of and relative distances between genes on a chromosome.Environment: The external elements and conditions which surround, influence, and affect the life and development of an organism or population.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Insurance Selection Bias: Adverse or favorable selection bias exhibited by insurers or enrollees resulting in disproportionate enrollment of certain groups of people.Escherichia coli: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.Computational Biology: A field of biology concerned with the development of techniques for the collection and manipulation of biological data, and the use of such data to make biological discoveries or predictions. This field encompasses all computational methods and theories for solving biological problems including manipulation of models and datasets.Drosophila melanogaster: A species of fruit fly much used in genetics because of the large size of its chromosomes.Clonal Selection, Antigen-Mediated: LYMPHOCYTE ACTIVATION by a specific ANTIGEN thus triggering clonal expansion of LYMPHOCYTES already capable of mounting an immune response to the antigen.Reproducibility of Results: The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.Gene Expression Profiling: The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.Genomics: The systematic study of the complete DNA sequences (GENOME) of organisms.Fertility: The capacity to conceive or to induce conception. It may refer to either the male or female.Receptors, Antigen, T-Cell: Molecules on the surface of T-lymphocytes that recognize and combine with antigens. The receptors are non-covalently associated with a complex of several polypeptides collectively called CD3 antigens (ANTIGENS, CD3). Recognition of foreign antigen and the major histocompatibility complex is accomplished by a single heterodimeric antigen-receptor structure, composed of either alpha-beta (RECEPTORS, ANTIGEN, T-CELL, ALPHA-BETA) or gamma-delta (RECEPTORS, ANTIGEN, T-CELL, GAMMA-DELTA) chains.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Population Density: Number of individuals in a population relative to space.Gene Library: A large collection of DNA fragments cloned (CLONING, MOLECULAR) from a given organism, tissue, organ, or cell type. It may contain complete genomic sequences (GENOMIC LIBRARY) or complementary DNA sequences, the latter being formed from messenger RNA and lacking intron sequences.Pigmentation: Coloration or discoloration of a part by a pigment.Choice Behavior: The act of making a selection among two or more alternatives, usually after a period of deliberation.Aptamers, Nucleotide: Nucleotide sequences, generated by iterative rounds of SELEX APTAMER TECHNIQUE, that bind to a target molecule specifically and with high affinity.Donor Selection: The procedure established to evaluate the health status and risk factors of the potential DONORS of biological materials. Donors are selected based on the principles that their health will not be compromised in the process, and the donated materials, such as TISSUES or organs, are safe for reuse in the recipients.Gene Duplication: Processes occurring in various organisms by which new genes are copied. Gene duplication may result in a MULTIGENE FAMILY; supergenes or PSEUDOGENES.Microsatellite Repeats: A variety of simple repeat sequences that are distributed throughout the GENOME. They are characterized by a short repeat unit of 2-8 basepairs that is repeated up to 100 times. They are also known as short tandem repeats (STRs).PrimatesDrug Resistance: Diminished or failed response of an organism, disease or tissue to the intended effectiveness of a chemical or drug. It should be differentiated from DRUG TOLERANCE which is the progressive diminution of the susceptibility of a human or animal to the effects of a drug, as a result of continued administration.Litter Size: The number of offspring produced at one birth by a viviparous animal.Population Dynamics: The pattern of any process, or the interrelationship of phenomena, which affects growth or change within a population.Ecosystem: A functional system which includes the organisms of a natural community together with their environment. (McGraw Hill Dictionary of Scientific and Technical Terms, 4th ed)Software: Sequential operating programs and data which instruct the functioning of a digital computer.Genome, Human: The complete genetic complement contained in the DNA of a set of CHROMOSOMES in a HUMAN. The length of the human genome is about 3 billion base pairs.Body Size: The physical measurements of a body.Drosophila: A genus of small, two-winged flies containing approximately 900 described species. These organisms are the most extensively studied of all genera from the standpoint of genetics and cytology.Geography: The science dealing with the earth and its life, especially the description of land, sea, and air and the distribution of plant and animal life, including humanity and human industries with reference to the mutual relations of these elements. (From Webster, 3d ed)Competitive Behavior: The direct struggle between individuals for environmental necessities or for a common goal.Cloning, Molecular: The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.Plasmids: Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.Mice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.Models, Theoretical: Theoretical representations that simulate the behavior or activity of systems, processes, or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).Pan troglodytes: The common chimpanzee, a species of the genus Pan, family HOMINIDAE. It lives in Africa, primarily in the tropical rainforests. There are a number of recognized subspecies.DNA Primers: Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.Amino Acid Substitution: The naturally occurring or experimentally induced replacement of one or more AMINO ACIDS in a protein with another. If a functionally equivalent amino acid is substituted, the protein may retain wild-type activity. Substitution may also diminish, enhance, or eliminate protein function. Experimentally induced substitution is often used to study enzyme activities and binding site properties.Oligonucleotide Array Sequence Analysis: Hybridization of a nucleic acid sample to a very large set of OLIGONUCLEOTIDE PROBES, which have been attached individually in columns and rows to a solid support, to determine a BASE SEQUENCE, or to detect variations in a gene sequence, GENE EXPRESSION, or for GENE MAPPING.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Genetic Vectors: DNA molecules capable of autonomous replication within a host cell and into which other DNA sequences can be inserted and thus amplified. Many are derived from PLASMIDS; BACTERIOPHAGES; or VIRUSES. They are used for transporting foreign genes into recipient cells. Genetic vectors possess a functional replicator site and contain GENETIC MARKERS to facilitate their selective recognition.Cluster Analysis: A set of statistical methods used to group variables or observations into strongly inter-related subgroups. In epidemiology, it may be used to analyze a closely grouped series of events or cases of disease or other health-related phenomenon with well-defined distribution patterns in relation to time or place or both.Personnel Selection: The process of choosing employees for specific types of employment. The concept includes recruitment.Genes, Plant: The functional hereditary units of PLANTS.Sex Characteristics: Those characteristics that distinguish one SEX from the other. The primary sex characteristics are the OVARIES and TESTES and their related hormones. Secondary sex characteristics are those which are masculine or feminine but not directly related to reproduction.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Data Interpretation, Statistical: Application of statistical procedures to analyze specific observed or assumed facts from a particular study.Genes, Insect: The functional hereditary units of INSECTS.Population: The total number of individuals inhabiting a particular region or area.Hybridization, Genetic: The genetic process of crossbreeding between genetically dissimilar parents to produce a hybrid.Haploidy: The chromosomal constitution of cells, in which each type of CHROMOSOME is represented once. Symbol: N.Multigene Family: A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)Genetic Loci: Specific regions that are mapped within a GENOME. Genetic loci are usually identified with a shorthand notation that indicates the chromosome number and the position of a specific band along the P or Q arm of the chromosome where they are found. For example the locus 6p21 is found within band 21 of the P-arm of CHROMOSOME 6. Many well known genetic loci are also known by common names that are associated with a genetic function or HEREDITARY DISEASE.Gene Flow: The change in gene frequency in a population due to migration of gametes or individuals (ANIMAL MIGRATION) across population barriers. In contrast, in GENETIC DRIFT the cause of gene frequency changes are not a result of population or gamete movement.Nucleic Acid Conformation: The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.Passeriformes: A widely distributed order of perching BIRDS, including more than half of all bird species.Immunoglobulin Variable Region: That region of the immunoglobulin molecule that varies in its amino acid sequence and composition, and comprises the binding site for a specific antigen. It is located at the N-terminus of the Fab fragment of the immunoglobulin. It includes hypervariable regions (COMPLEMENTARITY DETERMINING REGIONS) and framework regions.Sex Ratio: The number of males per 100 females.Proteins: Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.Genetic Linkage: The co-inheritance of two or more non-allelic GENES due to their being located more or less closely on the same CHROMOSOME.Epistasis, Genetic: A form of gene interaction whereby the expression of one gene interferes with or masks the expression of a different gene or genes. Genes whose expression interferes with or masks the effects of other genes are said to be epistatic to the effected genes. Genes whose expression is affected (blocked or masked) are hypostatic to the interfering genes.Mice, Inbred C57BLMutagenesis: Process of generating a genetic MUTATION. It may occur spontaneously or be induced by MUTAGENS.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Databases, Genetic: Databases devoted to knowledge about specific genes and gene products.Least-Squares Analysis: A principle of estimation in which the estimates of a set of parameters in a statistical model are those quantities minimizing the sum of squared differences between the observed values of a dependent variable and the values predicted by the model.Artificial Intelligence: Theory and development of COMPUTER SYSTEMS which perform tasks that normally require human intelligence. Such tasks may include speech recognition, LEARNING; VISUAL PERCEPTION; MATHEMATICAL COMPUTING; reasoning, PROBLEM SOLVING, DECISION-MAKING, and translation of language.Mutation Rate: The number of mutations that occur in a specific sequence, GENE, or GENOME over a specified period of time such as years, CELL DIVISIONS, or generations.Peptides: Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.Genome, Plant: The genetic complement of a plant (PLANTS) as represented in its DNA.T-Lymphocytes: Lymphocytes responsible for cell-mediated immunity. Two types have been identified - cytotoxic (T-LYMPHOCYTES, CYTOTOXIC) and helper T-lymphocytes (T-LYMPHOCYTES, HELPER-INDUCER). They are formed when lymphocytes circulate through the THYMUS GLAND and differentiate to thymocytes. When exposed to an antigen, they divide rapidly and produce large numbers of new T cells sensitized to that antigen.Inheritance Patterns: The different ways GENES and their ALLELES interact during the transmission of genetic traits that effect the outcome of GENE EXPRESSION.Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.Mammals: Warm-blooded vertebrate animals belonging to the class Mammalia, including all that possess hair and suckle their young.Stochastic Processes: Processes that incorporate some element of randomness, used particularly to refer to a time series of random variables.Analysis of Variance: A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.Heterozygote: An individual having different alleles at one or more loci regarding a specific character.Exons: The parts of a transcript of a split GENE remaining after the INTRONS are removed. They are spliced together to become a MESSENGER RNA or other functional RNA.Receptors, Antigen, T-Cell, alpha-beta: T-cell receptors composed of CD3-associated alpha and beta polypeptide chains and expressed primarily in CD4+ or CD8+ T-cells. Unlike immunoglobulins, the alpha-beta T-cell receptors recognize antigens only when presented in association with major histocompatibility (MHC) molecules.Introns: Sequences of DNA in the genes that are located between the EXONS. They are transcribed along with the exons but are removed from the primary gene transcript by RNA SPLICING to leave mature RNA. Some introns code for separate genes.Predatory Behavior: Instinctual behavior pattern in which food is obtained by killing and consuming other species.Pattern Recognition, Automated: In INFORMATION RETRIEVAL, machine-sensing or identification of visible patterns (shapes, forms, and configurations). (Harrod's Librarians' Glossary, 7th ed)Genetic Techniques: Chromosomal, biochemical, intracellular, and other methods used in the study of genetics.Clone Cells: A group of genetically identical cells all descended from a single common ancestral cell by mitosis in eukaryotes or by binary fission in prokaryotes. Clone cells also include populations of recombinant DNA molecules all carrying the same inserted sequence. (From King & Stansfield, Dictionary of Genetics, 4th ed)Book SelectionConserved Sequence: A sequence of amino acids in a polypeptide or of nucleotides in DNA or RNA that is similar across multiple species. A known set of conserved sequences is represented by a CONSENSUS SEQUENCE. AMINO ACID MOTIFS are often composed of conserved sequences.Birds: Warm-blooded VERTEBRATES possessing FEATHERS and belonging to the class Aves.Genes: A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.Saccharomyces cerevisiae: A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Flow Cytometry: Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.Gene Conversion: The asymmetrical segregation of genes during replication which leads to the production of non-reciprocal recombinant strands and the apparent conversion of one allele into another. Thus, e.g., the meiotic products of an Aa individual may be AAAa or aaaA instead of AAaa, i.e., the A allele has been converted into the a allele or vice versa.Probability: The study of chance processes or the relative frequency characterizing a chance process.Regression Analysis: Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In multiple regression, the dependent variable is considered to depend on more than a single independent variable.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Principal Component Analysis: Mathematical procedure that transforms a number of possibly correlated variables into a smaller number of uncorrelated variables called principal components.Genetic Engineering: Directed modification of the gene complement of a living organism by such techniques as altering the DNA, substituting genetic material by means of a virus, transplanting whole nuclei, transplanting cell hybrids, etc.Antigens, CD8: Differentiation antigens found on thymocytes and on cytotoxic and suppressor T-lymphocytes. CD8 antigens are members of the immunoglobulin supergene family and are associative recognition elements in MHC (Major Histocompatibility Complex) Class I-restricted interactions.Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.Sensitivity and Specificity: Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)RNA: A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)T-Lymphocyte Subsets: A classification of T-lymphocytes, especially into helper/inducer, suppressor/effector, and cytotoxic subsets, based on structurally or functionally different populations of cells.Body Weight: The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.Bacterial Proteins: Proteins found in any species of bacterium.Major Histocompatibility Complex: The genetic region which contains the loci of genes which determine the structure of the serologically defined (SD) and lymphocyte-defined (LD) TRANSPLANTATION ANTIGENS, genes which control the structure of the IMMUNE RESPONSE-ASSOCIATED ANTIGENS, HUMAN; the IMMUNE RESPONSE GENES which control the ability of an animal to respond immunologically to antigenic stimuli, and genes which determine the structure and/or level of the first four components of complement.Attention: Focusing on certain aspects of current experience to the exclusion of others. It is the act of heeding or taking notice or concentrating.Anti-Bacterial Agents: Substances that reduce the growth or reproduction of BACTERIA.Genome, Insect: The genetic complement of an insect (INSECTS) as represented in its DNA.Gene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.Protein Structure, Tertiary: The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.Protein Engineering: Procedures by which protein structure and function are changed or created in vitro by altering existing or synthesizing new structural genes that direct the synthesis of proteins with sought-after properties. Such procedures may include the design of MOLECULAR MODELS of proteins using COMPUTER GRAPHICS or other molecular modeling techniques; site-specific mutagenesis (MUTAGENESIS, SITE-SPECIFIC) of existing genes; and DIRECTED MOLECULAR EVOLUTION techniques to create new genes.Butterflies: Slender-bodies diurnal insects having large, broad wings often strikingly colored and patterned.Animals, Domestic: Animals which have become adapted through breeding in captivity to a life intimately associated with humans. They include animals domesticated by humans to live and breed in a tame condition on farms or ranches for economic reasons, including LIVESTOCK (specifically CATTLE; SHEEP; HORSES; etc.), POULTRY; and those raised or kept for pleasure and companionship, e.g., PETS; or specifically DOGS; CATS; etc.Food Preferences: The selection of one food over another.Genes, Bacterial: The functional hereditary units of BACTERIA.Support Vector Machines: Learning algorithms which are a set of related supervised computer learning methods that analyze data and recognize patterns, and used for classification and regression analysis.Genome, Bacterial: The genetic complement of a BACTERIA as represented in its DNA.Flowers: The reproductive organs of plants.Base Composition: The relative amounts of the PURINES and PYRIMIDINES in a nucleic acid.Sequence Homology, Nucleic Acid: The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.Nesting Behavior: Animal behavior associated with the nest; includes construction, effects of size and material; behavior of the adult during the nesting period and the effect of the nest on the behavior of the young.HIV-1: The type species of LENTIVIRUS and the etiologic agent of AIDS. It is characterized by its cytopathic effect and affinity for the T4-lymphocyte.Color: The visually perceived property of objects created by absorption or reflection of specific wavelengths of light.Crops, Agricultural: Cultivated plants or agricultural produce such as grain, vegetables, or fruit. (From American Heritage Dictionary, 1982)Genealogy and HeraldryTransformation, Genetic: Change brought about to an organisms genetic composition by unidirectional transfer (TRANSFECTION; TRANSDUCTION, GENETIC; CONJUGATION, GENETIC, etc.) and incorporation of foreign DNA into prokaryotic or eukaryotic cells by recombination of part or all of that DNA into the cell's genome.Zea mays: A plant species of the family POACEAE. It is a tall grass grown for its EDIBLE GRAIN, corn, used as food and animal FODDER.Poecilia: A genus of livebearing cyprinodont fish comprising the guppy and molly. Some species are virtually all female and depend on sperm from other species to stimulate egg development. Poecilia is used in carcinogenicity studies as well as neurologic and physiologic research.Ecology: The branch of science concerned with the interrelationship of organisms and their ENVIRONMENT, especially as manifested by natural cycles and rhythms, community development and structure, interactions between different kinds of organisms, geographic distributions, and population alterations. (Webster's, 3d ed)Animal Husbandry: The science of breeding, feeding and care of domestic animals; includes housing and nutrition.Diploidy: The chromosomal constitution of cells, in which each type of CHROMOSOME is represented twice. Symbol: 2N or 2X.Swine: Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).Monte Carlo Method: In statistics, a technique for numerically approximating the solution of a mathematical problem by studying the distribution of some random variable, often generated by a computer. The name alludes to the randomness characteristic of the games of chance played at the gambling casinos in Monte Carlo. (From Random House Unabridged Dictionary, 2d ed, 1993)Pollination: The transfer of POLLEN grains (male gametes) to the plant ovule (female gamete).Gene Expression Regulation: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.DNA, Plant: Deoxyribonucleic acid that makes up the genetic material of plants.RNA Splicing: The ultimate exclusion of nonsense sequences or intervening sequences (introns) before the final RNA transcript is sent to the cytoplasm.DNA, Mitochondrial: Double-stranded DNA of MITOCHONDRIA. In eukaryotes, the mitochondrial GENOME is circular and codes for ribosomal RNAs, transfer RNAs, and about 10 proteins.Kinetics: The rate dynamics in chemical or physical systems.DNA Transposable Elements: Discrete segments of DNA which can excise and reintegrate to another site in the genome. Most are inactive, i.e., have not been found to exist outside the integrated state. DNA transposable elements include bacterial IS (insertion sequence) elements, Tn elements, the maize controlling elements Ac and Ds, Drosophila P, gypsy, and pogo elements, the human Tigger elements and the Tc and mariner elements which are found throughout the animal kingdom.Cell SeparationSongbirds: PASSERIFORMES of the suborder, Oscines, in which the flexor tendons of the toes are separate, and the lower syrinx has 4 to 9 pairs of tensor muscles inserted at both ends of the tracheal half rings. They include many commonly recognized birds such as CROWS; FINCHES; robins; SPARROWS; and SWALLOWS.Drug Resistance, Microbial: The ability of microorganisms, especially bacteria, to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).H-Y Antigen: A sex-specific cell surface antigen produced by the sex-determining gene of the Y chromosome in mammals. It causes syngeneic grafts from males to females to be rejected and interacts with somatic elements of the embryologic undifferentiated gonad to produce testicular organogenesis.

*  Biology-Online • View topic - Theories - Origin of Life

So this is not mutations selected by natural selection but (although unintended) artificial selection. In fact this paper makes ... The reality is that most genetic changes occur as a result of cellular processes in response to stress, damage and copying ... Now lets see the description of Natural Selection according to this same wiki.. Natural selection is the gradual, non-random ... That sounds to me very much like artificial selection. Not a very good one at that, since we are now having to deal with the ...

*  Crop Science Abstract - Sl Family Recurrent Selection in Autogamous Crops Based on Dominant Genetic Male-Sterility | Digital...

Dominant genetic male-sterility, on the other hand, has not been widely used. Mass and half-sib family selection schemes have ... Sl Family Recurrent Selection in Autogamous Crops Based on Dominant Genetic Male-Sterility. View My Binders ... Recessive genetic male-sterility has been widely used to facilitate crossing in recurrent selection programs in autogamous crop ... The strengths of S1 family selection in a dominant genetic male-sterile program are that complete S1 family fertility ...

*  The Distribution of Fitness Effects of Beneficial Mutations in Pseudomonas aeruginosa

Author Summary Adaptation by natural selection depends on the spread of novel beneficial mutations, and one of the most ... This finding is consistent with existing population genetic models of adaptation based on statistical theory. When the fitness ... This distribution cannot be explained by population genetic theory, but it can be readily understood by considering the ... This study confirms an important prediction of population genetic theory, and it highlights the need to integrate statistical ...

*  Researchers measure importance of natural selection at genetic level

... By John Easton Medical Center Public Affairs Chung-I Wu. ... To measure the importance of selection at the genetic level, Wu and his former graduate students Justin Fay (Ph.D. 01) and ... Thirty-four of the 45 genes, or about 75 percent, showed no sign of natural selection. But, 11 genes, or about 25 percent ... At the same time, they tell us how much improvement we have constantly been making, all by means of natural selection. ...

*  Genetic Selection | Free Internet Radio | TuneIn

Listen to Genetic Selection Radio free online. Listen to free internet radio, sports, music, news, podcasts, talk, and ...

*  Selection, Genetic - Biodiversity Heritage Library

Contributions to the theory of natural selection : a series of essays. By: Wallace, Alfred Russel, ..., Genetic

*  Controlling parasitic worms with genetic selection | Feedstuffs

A key advantage to applying genetic selection rather than chemicals to get rid of the worms is that it is permanent and could ... One such strategy is genetic selection. Certain breeds of sheep are more immune to helminths than other breeds, and a breeding ... "With today's developments in genomic selection, breeding sheep for helminth resistance can be achieved efficiently, without ... adversely affecting other economically important traits," explained Karrow, a researcher at the Centre for Genetic Improvement ...

*  AgSource Cooperative Services - How To - Genetic Selection Guide

How To - Genetic Selection Guide. Follow the directions for identifying the highest 25% of genetic merit animals except for the ...

*  Employing effective feature selection in Genetic Fuzzy Rule-Based Classification Systems - IEEE Conference Publication

... for the effective selection of relevant features, when designing Genetic Fuzzy Rule-Based ... This paper proposes the use of a local feature selection scheme, ... Publications

*  Genetic Selection Tools

Selection Tools. 2008 * Differences in Commercial Pigs Representative of 1980 and 2005 Genetic Lines when reared on 1980 and ... Using Expected Progeny Differences for Swine Selection. M.T. See. Questions on Genetic Topics? E-mail Dr. Todd See ... Selection for Disease Resistance in the Pig. M.F. Rothschild. *Genetic Evaluations for Carcass Quality and Feed Efficiency at ... Genetic Improvement at the Commercial Level Compared to Genetic Progress at the Nucleus Level. Jan W.M. Merks ...

*  A Model-Based Approach for Identifying Signatures of Ancient Balancing Selection in Genetic Data

Finally, we performed a scan for balancing selection in Africans and Europeans using our new methods and identified a gene ... there has been little focus toward developing methods to identify regions of the genome that are under balancing selection. In ... methods that explicitly model the spatial distribution of polymorphism expected near a site under long-term balancing selection ... results show that our methods outperform commonly-used summary statistics for identifying regions under balancing selection. ...

*  Random Acts of Genetic Selection

Parents often try to tally the genetic contributions they make to their children. Perhaps your son has his father's smile, but ...

*  Data from: No fitness benefits of early molt in a fairy-wren: relaxed sexual selection under genetic monogamy? - Dryad

Data from: No fitness benefits of early molt in a fairy-wren: relaxed sexual selection under genetic monogamy?. Dryad ... Data from: No fitness benefits of early molt in a fairy-wren: relaxed sexual selection under genetic monogamy? ... The lack of EPP in this species might imply relaxed sexual selection on early molt with potential to lead to trait ... seasonal breeding plumage, pre-breeding molt timing, extra-pair paternity, relaxed sexual selection, monogamy, evolutionary ...

*  Feature Selection Using Age Layered Genetic Programming

... by Anthony Awuley. Supervisor: Brian Ross Visualization of feature ... "Feature Selection and Classification Using Age Layered Population Structure Genetic Programming",. A. Awuley and B.J. Ross, CEC ... Feature Selection and Classification Using Age Layered Population Structure Genetic Programming,. Anthony Awuley, MSc Thesis, ... FSALPS performs effective feature subset selection and classification of varied supervised learning tasks. It is a modication ...

*  "Neural vs. statistical classifier in conjunction with genetic algorithm based feature selection" by Ping...

The research in this paper proposes and investigates a neural-genetic algorithm for feature selection in conjunction with ... A computer based feature selection and classification system can provide a second opinion to the radiologists in assessment of ... statistical classifier in conjunction with genetic algorithm based feature selection. Pattern recognition letters * Ping Zhang ... The research in this paper proposes and investigates a neural-genetic algorithm for feature selection in conjunction with ...

*  Roulette Selection in Genetic Algorithms - Stack Overflow

Fitness proportionate selection, also known as roulette wheel selection, is a genetic operator used in genetic algorithms for ... Fitness proportionate selection , also known as roulette wheel selection , is a genetic operator used in genetic algorithms for ... Fitness proportionate selection , also known as roulette wheel selection , is a genetic operator used in genetic algorithms for ... Genetic Algorithms 14/30: The Roulette Wheel Selection Method. Lipowski, Roulette-wheel selection via stochastic acceptance ...

*  Alternating evolutionary pressure in a genetic algorithm facilitates protein model selection

Home » Alternating evolutionary pressure in a genetic algorithm facilitates protein model selection ... Nevertheless, there are still potential improvements to be made in template selection, refinement and protein model selection. ... AEP enabled the selection of the best models in 40% of all targets; compared to 25% for a normal GA. ... revealing several non-intuitive trends and explored a new strategy for protein conformation sampling using Genetic Algorithms ( ...

*  BishopBlog: Sample selection in genetic studies: impact of restricted range

Ramblings on academic-related matters. For information on my research see Twin analysis blog: . ERP time-frequency analysis blog: . For tweets, follow @deevybee.. ...


SEX: DIFFERENCES IN MUTATION, RECOMBINATION, SELECTION, GENE FLOW, AND GENETIC DRIFT. Authors. *. Philip W. Hedrick. * School ... Jingjing Yan, Jing Jing, Xiaoyu Mu, Huixia Du, Meilin Tian, Shi Wang, Wei Lu, Zhenmin Bao, A genetic linkage map of the sea ... Eric R. Waits, John Martinson, Brian Rinner, Stephen Morris, Dina Proestou, Denise Champlin, Diane Nacci, Genetic Linkage Map ... the two sexes can be used in a population genetics context unless there are sex-specific differences in selection or genetic ...

*  PGASelect - performs genetic algorithm selection using either the

PGASelect - performs genetic algorithm selection using either the default selection scheme or that specified with ... Valid selection methods are proportional, stochastic universal, tournament, or probabilistic tournament selection, PGA_SELECT_ ...

*  Stress-strain properties of individual Merino wool fibres are minor contributors to variations in staple strength induced by...

... of individual Merino wool fibres are minor contributors to variations in staple strength induced by genetic selection and ... Selection directly for staple strength or indirectly using the fibre diameter variability traits is an effective method to ... of individual Merino wool fibres are minor contributors to variations in staple strength induced by genetic selection and ... Average staple strength differed by 5 N/ktex between 'sound' and 'tender' selection flocks and 18 N/ktex between extreme ...

*  Selection of new clones of linalool chemotype from genetic recombination in Lippia alba

RUFINO, Elcio Rodrigo et al. Seleção de novos clones de quimiotipo linalol em Lippia alba oriundos de recombinação genética. Bragantia [online]. 2012, vol.71, n.2, pp.155-164. Epub July 19, 2012. ISSN 0006-8705. A espécie Lippia alba, aromática e medicinal, é nativa da América do Sul (Mata Atlântica) e possui muito vigor e rusticidade. Por ser espécie alógama e autoincompatível, as populações naturais possuem elevada variabilidade morfológica e química. O presente trabalho teve por objetivo realizar uma triagem prévia para identificação de novos clones promissores, oriundos de uma população-base inédita (recombinante) de Lippia alba quanto às características agronômicas e fitoquímicas, tendo como modelo o óleo ou quimiotipo linalol. Como controles, utilizaram-se os dois melhores clones linalol, obtidos por coleta. As características avaliadas foram: massa seca de folhas (MSF), rendimento de óleo (RD%), produção ...

*  Genetic evidence for natural selection in humans in the contemporary United States | bioRxiv

Genetic evidence for natural selection in humans in the contemporary United States. Jonathan Beauchamp ... Genetic evidence for natural selection in humans in the contemporary United States ... Genetic evidence for natural selection in humans in the contemporary United States ... Genetic evidence for natural selection in humans in the contemporary United States ...

*  The Genetic Architecture of Response to Long-Term Artificial Selection for Oil Concentration in the Maize Kernel | Genetics

The Genetic Architecture of Response to Long-Term Artificial Selection for Oil Concentration in the Maize Kernel. Cathy C. ... The Genetic Architecture of Response to Long-Term Artificial Selection for Oil Concentration in the Maize Kernel. Cathy C. ... The Genetic Architecture of Response to Long-Term Artificial Selection for Oil Concentration in the Maize Kernel. Cathy C. ... Walsh, B., 2004 Population- and quantitative-genetic models of selection limits. Plant Breed. Rev. 24(Pt. 1): 177-225. ...

*  The Causal Structure of Evolutionary Theory - Philsci-Archive

Evolution, Causation, Natural Selection, Genetic Drift, Driftability, Fitness, Propensity. Subjects:. Specific Sciences , ... The causalist side, on the other hand, holds that populations can change in response to selection-one can cite fitness ... The former understand core evolutionary concepts like fitness and selection to be mere statistical summaries of underlying ... In this view, evolutionary changes cannot be causally explained by selection or fitness. ...

Selection (relational algebra): In relational algebra, a selection (sometimes called a restriction to avoid confusion with SQL's use of SELECT) is a unary operation written asMolecular evolution: Molecular evolution is a change in the sequence composition of cellular molecules such as DNA, RNA, and proteins across generations. The field of molecular evolution uses principles of evolutionary biology and population genetics to explain patterns in these changes.Genetic variation: right|thumbColes PhillipsPanmixia: Panmixia (or panmixis) means random mating.King C and Stanfield W.Branching order of bacterial phyla (Gupta, 2001): There are several models of the Branching order of bacterial phyla, one of these was proposed in 2001 by Gupta based on conserved indels or protein, termed "protein signatures", an alternative approach to molecular phylogeny. Some problematic exceptions and conflicts are present to these conserved indels, however, they are in agreement with several groupings of classes and phyla.Silent mutation: Silent mutations are mutations in DNA that do not significantly alter the phenotype of the organism in which they occur. Silent mutations can occur in non-coding regions (outside of genes or within introns), or they may occur within exons.Symmetry element: A symmetry element is a point of reference about which symmetry operations can take place. In particular, symmetry elements can be centers of inversion, axes of rotation and mirror planes.Phenotype microarray: The phenotype microarray approach is a technology for high-throughput phenotyping of cells.Biological ornament: A biological ornament is a secondary sexual characteristic of an animal that appears to serve a decorative function rather than an ostensible, utilitarian function. Ornaments are used in displays to attract mates in a process known as sexual selection.Infinite alleles model: The infinite alleles model is a mathematical model for calculating genetic mutations. The Japanese geneticist Motoo Kimura and American geneticist James F.Microevolution: Microevolution is the change in allele frequencies that occur over time within a population.Microevolution: What is microevolution?DNA sequencer: A DNA sequencer is a scientific instrument used to automate the DNA sequencing process. Given a sample of DNA, a DNA sequencer is used to determine the order of the four bases: G (guanine), C (cytosine), A (adenine) and T (thymine).Clonal Selection Algorithm: In artificial immune systems, Clonal selection algorithms are a class of algorithms inspired by the clonal selection theory of acquired immunity that explains how B and T lymphocytes improve their response to antigens over time called affinity maturation. These algorithms focus on the Darwinian attributes of the theory where selection is inspired by the affinity of antigen-antibody interactions, reproduction is inspired by cell division, and variation is inspired by somatic hypermutation.Inbreeding depression: Inbreeding depression is the reduced biological fitness in a given population as a result of inbreeding, or breeding of related individuals. Population biological fitness refers to its ability to survive and reproduce itself.Reproductive toxicity: Reproductive toxicity is a hazard associated with some chemical substances, that they will interfere in some way with normal reproduction; such substances are called reprotoxic. It includes adverse effects on sexual function and fertility in adult males and females, as well as developmental toxicity in the offspring.Protein primary structure: The primary structure of a peptide or protein is the linear sequence of its amino acid structural units, and partly comprises its overall biomolecular structure. By convention, the primary structure of a protein is reported starting from the amino-terminal (N) end to the carboxyl-terminal (C) end.Interval boundary element method: Interval boundary element method is classical boundary element method with the interval parameters.
Hassall's corpuscles: Hassall's corpuscles (or thymic corpuscles (bodies)) are structures found in the medulla of the human thymus, formed from eosinophilic type VI epithelial reticular cells arranged concentrically. These concentric corpuscles are composed of a central mass, consisting of one or more granular cells, and of a capsule formed of epithelioid cells.Sexual motivation and hormones: Sexual motivation is influenced by hormones such as testosterone, estrogen, progesterone, oxytocin, and vasopressin. In most mammalian species, sex hormones control the ability to engage in sexual behaviours.Decoding methods: In coding theory, decoding is the process of translating received messages into codewords of a given code. There have been many common methods of mapping messages to codewords.Recombination (cosmology): In cosmology, recombination refers to the epoch at which charged electrons and protons first became bound to form electrically neutral hydrogen atoms.Note that the term recombination is a misnomer, considering that it represents the first time that electrically neutral hydrogen formed.Gene polymorphismCodon Adaptation Index: The Codon Adaptation Index (CAI) is the most widespread technique for analyzing Codon usage bias. As opposed to other measures of codon usage bias, such as the 'effective number of codons' (Nc), which measure deviation from a uniform bias (null hypothesis), CAI measures the deviation of a given protein coding gene sequence with respect to a reference set of genes.Biopanning: Biopanning is an affinity selection technique which selects for peptides that bind to a given target.Ehrlich GK, Berthold W, and Bailon P.Hyperparameter: In Bayesian statistics, a hyperparameter is a parameter of a prior distribution; the term is used to distinguish them from parameters of the model for the underlying system under analysis.Matrix model: == Mathematics and physics ==Inverse probability weighting: Inverse probability weighting is a statistical technique for calculating statistics standardized to a population different from that in which the data was collected. Study designs with a disparate sampling population and population of target inference (target population) are common in application.CS-BLASTList of sequenced eukaryotic genomesMaladaptation: A maladaptation () is a trait that is (or has become) more harmful than helpful, in contrast with an adaptation, which is more helpful than harmful. All organisms, from bacteria to humans, display maladaptive and adaptive traits.WGAViewer: WGAViewer is a bioinformatics software tool which is designed to visualize, annotate, and help interpret the results generated from a genome wide association study (GWAS). Alongside the P values of association, WGAViewer allows a researcher to visualize and consider other supporting evidence, such as the genomic context of the SNP, linkage disequilibrium (LD) with ungenotyped SNPs, gene expression database, and the evidence from other GWAS projects, when determining the potential importance of an individual SNP.Disequilibrium (medicine): Disequilibrium}}Chromosome regionsEvolution in Variable EnvironmentTemporal analysis of products: Temporal Analysis of Products (TAP), (TAP-2), (TAP-3) is an experimental technique for studyingList of strains of Escherichia coli: Escherichia coli is a well studied bacterium that was first identified by Theodor Escherich, after whom it was later named.PSI Protein Classifier: PSI Protein Classifier is a program generalizing the results of both successive and independent iterations of the PSI-BLAST program. PSI Protein Classifier determines belonging of the found by PSI-BLAST proteins to the known families.Indy (gene): Indy, short for I'm not dead yet, is a gene of the model organism, the fruit fly Drosophila melanogaster. Mutant versions of this gene have doubled the average life span of fruit flies in at least one set of experiments, but this result has been subject to controversy.Generalizability theory: Generalizability theory, or G Theory, is a statistical framework for conceptualizing, investigating, and designing reliable observations. It is used to determine the reliability (i.Gene signature: A gene signature is a group of genes in a cell whose combined expression patternItadani H, Mizuarai S, Kotani H. Can systems biology understand pathway activation?Ontario Genomics Institute: The Ontario Genomics Institute (OGI) is a not-for-profit organization that manages cutting-edge genomics research projects and platforms.The Ontario Genomics Institute OGI also helps scientists find paths to the marketplace for their discoveries and the products to which they lead, and it works through diverse outreach and educational activities to raise awareness and facilitate informed public dialogue about genomics and its social impacts.Low Fertility Cohorts Study: The Low Fertility Cohorts Study, 1978: A Survey of White, Ever-Married Women Belonging to the 1901-1910 United States Birth Cohorts,Data Sharing For Demographic Research consists of personal interviews of white, ever-married women born between July 1, 1900, and June 30, 1910. In 1978, a national survey of 1,049 married women between the ages of 68 and 78 were interviewed between the months of March and July in order to investigate low fertility during the 1920s and 1930s and the women of childbearing age during those decades.Kinetic-segregation model of T cell activationThermal cyclerThreshold host density: Threshold host density (NT), in the context of wildlife disease ecology, refers to the concentration of a population of a particular organism as it relates to disease. Specifically, the threshold host density (NT) of a species refers to the minimum concentration of individuals necessary to sustain a given disease within a population.Library (biology): In molecular biology, a library is a collection of DNA fragments that is stored and propagated in a population of micro-organisms through the process of molecular cloning. There are different types of DNA libraries, including cDNA libraries (formed from reverse-transcribed RNA), genomic libraries (formed from genomic DNA) and randomized mutant libraries (formed by de novo gene synthesis where alternative nucleotides or codons are incorporated).Acromelanism: Acromelanism is a genetically determined, temperature-dependent pigmentation pattern, with full expression only occurring on legs, ears, tail and face. Seen in Siamese and Himalayan cats, rats, and rabbits.Helix–coil transition model: Helix–coil transition models are formalized techniques in statistical mechanics developed to describe conformations of linear polymers in solution. The models are usually but not exclusively applied to polypeptides as a measure of the relative fraction of the molecule in an alpha helix conformation versus turn or random coil.Gene duplication: Gene duplication (or chromosomal duplication or gene amplification) is a major mechanism through which new genetic material is generated during molecular evolution. It can be defined as any duplication of a region of DNA that contains a gene.Microsatellite: A microsatellite is a tract of repetitive DNA in which certain DNA motifs (ranging in length from 2–5 base pairs) are repeated, typically 5-50 times. Microsatellites occur at thousands of locations in the human genome and they are notable for their high mutation rate and high diversity in the population.Deep litter: Deep litter is an animal housing system, based on the repeated spreading of straw or sawdust material in indoor booths. An initial layer of litter is spread for the animals to use for bedding material and to defecate in, and as the litter is soiled, new layers of litter are continuously added by the farmer.Matrix population models: Population models are used in population ecology to model the dynamics of wildlife or human populations. Matrix population models are a specific type of population model that uses matrix algebra.EcosystemMac OS X Server 1.0Restricted isometry property: In linear algebra, the restricted isometry property characterizes matrices which are nearly orthonormal, at least when operating on sparse vectors. The concept was introduced by Emmanuel Candès and Terence TaoE.Drosophila embryogenesis: Drosophila embryogenesis, the process by which Drosophila (fruit fly) embryos form, is a favorite model system for geneticists and developmental biologists studying embryogenesis. The small size, short generation time, and large brood size make it ideal for genetic studies.Health geography: Health geography is the application of geographical information, perspectives, and methods to the study of health, disease, and health care.Ligation-independent cloning: Ligation-independent cloning (LIC) is a form of molecular cloning that is able to be performed without the use of restriction endonucleases or DNA ligase. This allows genes that have restriction sites to be cloned without worry of chopping up the insert.Triparental mating: Triparental mating is a form of Bacterial conjugation where a conjugative plasmid present in one bacterial strain assists the transfer of a mobilizable plasmid present in a second bacterial strain into a third bacterial strain. Plasmids are introduced into bacteria for such purposes as transformation, cloning, or transposon mutagenesis.Von Neumann regular ring: In mathematics, a von Neumann regular ring is a ring R such that for every a in R there exists an x in R such that . To avoid the possible confusion with the regular rings and regular local rings of commutative algebra (which are unrelated notions), von Neumann regular rings are also called absolutely flat rings, because these rings are characterized by the fact that every left module is flat.DNA condensation: DNA condensation refers to the process of compacting DNA molecules in vitro or in vivo. Mechanistic details of DNA packing are essential for its functioning in the process of gene regulation in living systems.The Chimps of Fauna Sanctuary: The Chimps of Fauna Sanctuary: A Canadian Story of Resilience and Recovery is a non-fiction book, written by Canadian writer Andrew Westoll, first published in May 2011 by Harper Collins. In the book, the author chronicles the time he spent volunteering at the Fauna Sanctuary, an animal refuge in Quebec for chimpanzees that had been used for biomedical research.Cellular microarray: A cellular microarray is a laboratory tool that allows for the multiplex interrogation of living cells on the surface of a solid support. The support, sometimes called a "chip", is spotted with varying materials, such as antibodies, proteins, or lipids, which can interact with the cells, leading to their capture on specific spots.Reaction coordinateDNA binding site: DNA binding sites are a type of binding site found in DNA where other molecules may bind. DNA binding sites are distinct from other binding sites in that (1) they are part of a DNA sequence (e.Multiple cloning site: A multiple cloning site (MCS), also called a polylinker, is a short segment of DNA which contains many (up to ~20) restriction sites - a standard feature of engineered plasmids. Restriction sites within an MCS are typically unique, occurring only once within a given plasmid.

(1/8766) The Lewontin and Krakauer test on quantitative characters.

It is shown that LEWONTIN and KRAKAUER's test could also be applied to quantitative characters that do not show important dominance and epistatic genetic variances. The design of experiments for this purpose and the error of the estimation of F are discussed.  (+info)

(2/8766) Predicting insecticide resistance: mutagenesis, selection and response.

Strategies to manage resistance to a particular insecticide have usually been devised after resistance has evolved. If it were possible to predict likely resistance mechanisms to novel insecticides before they evolved in the field, it might be feasible to have programmes that manage susceptibility. With this approach in mind, single-gene variants of the Australian sheep blowfly, Lucilia cuprina, resistant to dieldrin, diazinon and malathion, were selected in the laboratory after mutagenesis of susceptible strains. The genetic and molecular bases of resistance in these variants were identical to those that had previously evolved in natural populations. Given this predictive capacity for known resistances, the approach was extended to anticipate possible mechanisms of resistance to cyromazine, an insecticide to which L. cuprina populations remain susceptible after almost 20 years of exposure. Analysis of the laboratory-generated resistant variants provides an explanation for this observation. The variants show low levels of resistance and a selective advantage over susceptibles for only a limited concentration range. These results are discussed in the context of the choice of insecticides for control purposes and of delivery strategies to minimize the evolution of resistance.  (+info)

(3/8766) The alcohol dehydrogenase polymorphism in populations of Drosophila melanogaster. I. Selection in different environments.

The allozyme polymorphism at the alcohol dehydrogenase locus in Drosophila melanogaster was studied in order to obtain experimental evidence about the maintenance of this polymorphism. Populations started with different initial allele frequencies from homozygous F and S lines showed a convergence of frequencies on regular food at 25 degrees, leading to values equal to those in the base populations. These results were interpreted as due to some kind of balancing selection. In populations kept at 29.8 degrees, a lower equilibrium F frequency was attained. Addition of ethanol and some other alcohols to the food gave a rapid increase in F frequency, and high humidity decreased the F frequency slightly. Combination or alternation of ethanol and high humidity had variable effects in the populations tested. For a further analysis of the allele-frequency changes, estimates were obtained for egg-to-adult survival under different conditions and for adult survival on ethanol-supplemented food. On ethanol food (both at regular and high humidity), egg-to-adult survival of SS homozygotes was considerably lower than that of the FF and FS genotypes. Under regular conditions of food, temperature and humidity, a tendency to heterozygote superiority was observed, while at high humidity a relative high survival of SS was noticed in some tests. Adult survival of SS was lower than that of FF, but FS was generally intermediate, though the degree of dominance differed between populations. The results are consistent with the hypothesis of the occurrence of selection at the Adh locus.  (+info)

(4/8766) High throughput direct end sequencing of BAC clones.

Libraries constructed in bacterial artificial chromosome (BAC) vectors have become the choice for clone sets in high throughput genomic sequencing projects primarily because of their high stability. BAC libraries have been proposed as a source for minimally over-lapping clones for sequencing large genomic regions, and the use of BAC end sequences (i.e. sequences adjoining the insert sites) has been proposed as a primary means for selecting minimally overlapping clones for sequencing large genomic regions. For this strategy to be effective, high throughput methods for BAC end sequencing of all the clones in deep coverage BAC libraries needed to be developed. Here we describe a low cost, efficient, 96 well procedure for BAC end sequencing. These methods allow us to generate BAC end sequences from human and Arabidoposis libraries with an average read length of >450 bases and with a single pass sequencing average accuracy of >98%. Application of BAC end sequences in genomic sequen-cing is discussed.  (+info)

(5/8766) Improving the efficiency of artificial selection: more selection pressure with less inbreeding.

The use of population genetic variability in present-day selection schemes can be improved to reduce inbreeding rate and inbreeding depression without impairing genetic progress. We performed an experiment with Drosophila melanogaster to test mate selection, an optimizing method that uses linear programming to maximize the selection differential applied while at the same time respecting a restriction on the increase in inbreeding expected in the next generation. Previous studies about mate selection used computer simulation on simple additive genetic models, and no experiment with a real character in a real population had been carried out. After six selection generations, the optimized lines showed an increase in cumulated phenotypic selection differential of 10.76%, and at the same time, a reduction of 19.91 and 60.47% in inbreeding coefficient mean and variance, respectively. The increased selection pressure would bring greater selection response, and in fact, the observed change in the selected trait was on average 31.03% greater in the optimized lines. These improvements in the selection scheme were not made at the expense of the long-term expectations of genetic variability in the population, as these expectations were very similar for both mate selection and conventionally selected lines in our experiment.  (+info)

(6/8766) Prediction of genetic contributions and generation intervals in populations with overlapping generations under selection.

A method to predict long-term genetic contributions of ancestors to future generations is studied in detail for a population with overlapping generations under mass or sib index selection. An existing method provides insight into the mechanisms determining the flow of genes through selected populations, and takes account of selection by modeling the long-term genetic contribution as a linear regression on breeding value. Total genetic contributions of age classes are modeled using a modified gene flow approach and long-term predictions are obtained assuming equilibrium genetic parameters. Generation interval was defined as the time in which genetic contributions sum to unity, which is equal to the turnover time of genes. Accurate predictions of long-term genetic contributions of individual animals, as well as total contributions of age classes were obtained. Due to selection, offspring of young parents had an above-average breeding value. Long-term genetic contributions of youngest age classes were therefore higher than expected from the age class distribution of parents, and generation interval was shorter than the average age of parents at birth of their offspring. Due to an increased selective advantage of offspring of young parents, generation interval decreased with increasing heritability and selection intensity. The method was compared to conventional gene flow and showed more accurate predictions of long-term genetic contributions.  (+info)

(7/8766) Natural selection of the Pol gene of bovine immunodeficiency virus.

Genetic variability is a salient feature of lentiviruses, contributing to the pathogenesis of these viruses by enabling them to persist in the host and to resist anti-retroviral treatment. Bovine immunodeficiency virus (BIV), a lentivirus of unknown pathology, infects cattle in the United States and worldwide. Genetic diversity of BIV that is associated with naturally infected cattle is not well studied. We examined the genetic diversity and natural selection of a segment of the BIV pol gene amplified from the leukocyte DNA of naturally infected cattle. A portion of the reverse transcriptase domain (183 bp) of the pol region was targeted for amplification by PCR. PCR products were sequenced directly and aligned. When compared to the sequences of BIV R29-127, a molecular clone of the original BIV R29 isolate, all isolates were greater than 91% identical in nucleotide sequences and 77% identical in amino acid sequences. Pol genotypes were polymorphic at 14% of the nucleotide sites. The ratio of nonsynonymous to synonymous nucleotide substitutions (relative to the number of respective sites, Ka/Ks) was 0.16, indicating that this region of the BIV genome, like that of HIV-1, is subject to purifying selection. Based on the McDonald-Kreitman analysis, this region also was under positive Darwinian selection as HIV-1 and BIV diverged from a common progenitor. Phylogenetic analysis revealed that genotypes were geographically distinct, possibly indicating a common source of infection for animals within a herd.  (+info)

(8/8766) Another set of responses and correlated responses to selection on age at reproduction in Drosophila melanogaster.

Ageing is the decline in survival probability and fertility later in adult life. It can evolve through mutation accumulation and pleiotropy. Artificial selection by age at reproduction is a useful method for detecting the effects of pleiotropy, and for producing lines that differ in their rate of ageing for further analysis. However, the approach has encountered difficulties from gene-environment interaction and inadvertent selection. We have produced a new set of selection lines in Drosophila melanogaster, breeding from either 'young' or 'old' adults, and avoiding some of the difficulties present in previous studies. Breeding from older adults resulted in an evolutionary increase in survival but, contrary to all previous studies using this method, in no increase in late-life fertility. The increase in survival was accompanied by an evolutionary decline in fertility early in adult life, confirming the importance of pleiotropy in the evolution of ageing. Contrary to previous studies, there were no correlated responses to selection in the pre-adult period; development time, larval competitive ability and adult size achieved did not differ between the lines from the two selection regimes.  (+info)


  • Molecular population genetics aims to explain genetic variation and molecular evolution from population genetics principles. (
  • The field was born 50 years ago with the first measures of genetic variation in allozyme loci, continued with the nucleotide sequencing era, and is currently in the era of population genomics. (
  • The conceptual elegance of the neutral theory of molecular evolution or the footprint carved by natural selection on the patterns of genetic variation are two examples of the vast number of inspiring findings of population genetics research. (
  • But evolutionary geneticists familiar with the work expect these to be the first in a series of papers that will rigorously test the theory by taking advantage of the genomic tools and data and will determine how much of existing genetic variation matters in the competition for survival. (


  • Dominant genetic male-sterility, on the other hand, has not been widely used. (
  • Mass and half-sib family selection schemes have been described for the dominant male-sterile program. (
  • Our objective was to describe S 1 family recurrent selection schemes and expected selection responses for the dominant male-sterile program. (
  • The strengths of S 1 family selection in a dominant genetic male-sterile program are that complete S 1 family fertility eliminates the problem of male-sterile phenotype pleiotropy and selection response per year is often greater for S 1 compared to mass or half-sib family recurrent selection. (
  • The weakness of S 1 family selection in a dominant compared to a recessive male-sterile program is that expected selection response is less than that for S 1 family selection in allogamous species where intermating is done strictly between S 1 selected families. (


  • We describe the different genetic data sets made available by advances in molecular technologies, and the theoretical developments fostered by these data. (

natural selection

  • We argue that where female mate preference and opposing natural selection against conspicuous males have produced a stable equilibrium in male trait genotype, a reversed female mate preference may invade the population, initially assisted by reduced male mortality. (
  • Researchers from the University have demonstrated that natural selection plays a much larger role in molecular evolution than anyone had suspected. (
  • Less than 1 percent of them make enough of a difference that they either are embraced or expunged by natural selection. (
  • Thirty-four of the 45 genes, or about 75 percent, showed no sign of natural selection. (
  • They estimate that the average human carries about 500 harmful mutations, which are destined to be removed from the population by natural selection, but transiently pile up before their exit. (
  • In the 1960s, researchers realized that underneath the few obvious differences between related species there were millions of DNA variations, far too many for natural selection to sort out. (
  • He argued that the great bulk of DNA changes were neutral, biologically insignificant consequences of random mutation, and seldom if ever driven by natural selection. (


  • According to the neutral theory, many small genetic changes randomly occur, but the vast majority of them simply do not matter. (


  • Genetic algorithms (GAs) have received significant interest from researchers and have been applied to various optimization problems. (


  • In this paper, a methodology for model structure selection based on a genetic algorithm was developed and applied to non-linear discrete-time dynamic systems. (


  • These schemes include S 1 family recurrent selection using the reference population as the male-sterile allele source and combined S 1 and half-sib or S 1 and full-sib family recurrent selection using half-sib or full-sib families, respectively, as the male-sterile allele source. (


  • Data from the previous study allowed them to estimate the number of fixed good mutations, which distinguish humans from monkeys, and the number of residual bad mutations, genetic flaws that have piled up in the genome and are slowly being eliminated. (


  • So Kimura developed a mathematical framework to explain how evolution worked at the genetic level. (


  • Expected selection responses were described for selection of the same or different traits in different family types for combined family type selection schemes. (
  • To measure the importance of selection at the genetic level, Wu and his former graduate students Justin Fay (Ph.D. 01) and Gerald Wyckoff (Ph.D. 00) tallied the minute variations within each of the 45 genes among flies of one species (Drosophila melanogaster) and contrasted them with the same genes from a different species (Drosophila simulans). (


  • In recent years, extensive works on genetic algorithms have been reported covering various applications. (
  • We proposed various S 1 family recurrent selection schemes where intermating is done between selected S 1 families and a male-sterile allele source as a means for overcoming this problem. (


  • We'll start on Tuesday by answering any questions left over from Nora's lectures last week on detecting selection on molecular sequences and on evolution in multigene families. (
  • I've posted notes for next week's lectures about detecting selection on nucleotide sequences (which will introduce you to Tajima's D ) and on evolution in multigene families (which will introduce you to orthology, paralogy, and concerted evolution). (