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.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.Genetic Variation: Genotypic differences observed among individuals in a population.Genetic Speciation: The splitting of an ancestral species into daughter species that coexist in time (King, Dictionary of Genetics, 6th ed). Causal factors may include geographic isolation, HABITAT geometry, migration, REPRODUCTIVE ISOLATION, random GENETIC DRIFT and MUTATION.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).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)Regional Blood Flow: The flow of BLOOD through or around an organ or region of the body.Blood Flow Velocity: A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.Hybridization, Genetic: The genetic process of crossbreeding between genetically dissimilar parents to produce a hybrid.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.Animal Migration: Periodic movements of animals in response to seasonal changes or reproductive instinct. Hormonal changes are the trigger in at least some animals. Most migrations are made for reasons of climatic change, feeding, or breeding.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.Genetic Structures: The biological objects that contain genetic information and that are involved in transmitting genetically encoded traits from one organism to another.Phylogeography: A field of study concerned with the principles and processes governing the geographic distributions of genealogical lineages, especially those within and among closely related species. (Avise, J.C., Phylogeography: The History and Formation of Species. Harvard University Press, 2000)Reproductive Isolation: Mechanisms that prevent different populations from exchanging genes (GENE FLOW), resulting in or maintaining GENETIC SPECIATION. It can either prevent mating to take place or ensure that any offspring produced is either inviable or sterile, thereby preventing further REPRODUCTION.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Genetic Drift: The fluctuation of the ALLELE FREQUENCY from one generation to the next.Population Dynamics: The pattern of any process, or the interrelationship of phenomena, which affects growth or change within a population.Amplified Fragment Length Polymorphism Analysis: The detection of RESTRICTION FRAGMENT LENGTH POLYMORPHISMS by selective PCR amplification of restriction fragments derived from genomic DNA followed by electrophoretic analysis of the amplified restriction fragments.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.Pollen: The fertilizing element of plants that contains the male GAMETOPHYTES.Gene Pool: The total genetic information possessed by the reproductive members of a POPULATION of sexually reproducing organisms.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.GibraltarEcosystem: 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)Evolution, Molecular: The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.Sympatry: In evolutionary theory, overlapping geographic distribution of diverging species. In sympatric GENETIC SPECIATION, genetic diversion occurs without geographic separation.Selection, Genetic: Differential and non-random reproduction of different genotypes, operating to alter the gene frequencies within a population.Reproduction: The total process by which organisms produce offspring. (Stedman, 25th ed)Biological Evolution: The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.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.Pollination: The transfer of POLLEN grains (male gametes) to the plant ovule (female gamete).Atlantic OceanAfrica, Northern: The geographical area of Africa comprising ALGERIA; EGYPT; LIBYA; MOROCCO; and TUNISIA. It includes also the vast deserts and oases of the Sahara. It is often referred to as North Africa, French-speaking Africa, or the Maghreb. (From Webster's New Geographical Dictionary, 1988, p856)Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Pulsatile Flow: Rhythmic, intermittent propagation of a fluid through a BLOOD VESSEL or piping system, in contrast to constant, smooth propagation, which produces laminar flow.Endangered Species: An animal or plant species in danger of extinction. Causes can include human activity, changing climate, or change in predator/prey ratios.Gene Frequency: The proportion of one particular in the total of all ALLELES for one genetic locus in a breeding POPULATION.Butterflies: Slender-bodies diurnal insects having large, broad wings often strikingly colored and patterned.Population Density: Number of individuals in a population relative to space.Seed Dispersal: The various physical methods which include wind, insects, animals, tension, and water, by which a plant scatters its seeds away from the parent plant.Inbreeding: The mating of plants or non-human animals which are closely related genetically.DNA, Plant: Deoxyribonucleic acid that makes up the genetic material of plants.Trees: Woody, usually tall, perennial higher plants (Angiosperms, Gymnosperms, and some Pterophyta) having usually a main stem and numerous branches.Lecythidaceae: A plant family of the order Lecythidales, subclass Dilleniidae, class Magnoliopsida.Quercus: A plant genus of the family FAGACEAE that is a source of TANNINS. Do not confuse with Holly (ILEX).Genetic Markers: A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.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.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.Pinus: A plant genus in the family PINACEAE, order Pinales, class Pinopsida, division Coniferophyta. They are evergreen trees mainly in temperate climates.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.Chromosomes, Human, Y: The human male sex chromosome, being the differential sex chromosome carried by half the male gametes and none of the female gametes in humans.Seeds: The encapsulated embryos of flowering plants. They are used as is or for animal feed because of the high content of concentrated nutrients like starches, proteins, and fats. Rapeseed, cottonseed, and sunflower seed are also produced for the oils (fats) they yield.Central AmericaPolymorphism, 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.Demography: Statistical interpretation and description of a population with reference to distribution, composition, or structure.Eagles: Large members of the FALCONIFORMES order of birds, family Accipitridae, most especially the genera Aquila, Haliaeetus, Harpia, and Circaetus. They are characterized by their powerful talons, which carry long, curved, pointed claws and by their opposable hindtoe.Fraxinus: A plant genus of the family OLEACEAE. Members contain secoiridoid glucosides.Human Migration: Periodic movement of human settlement from one geographical location to another.DNA, Chloroplast: Deoxyribonucleic acid that makes up the genetic material of CHLOROPLASTS.Ranunculus: A plant genus of the family RANUNCULACEAE that contains protoanemonin, anemonin, and ranunculin.Mediterranean Region: The MEDITERRANEAN SEA, the MEDITERRANEAN ISLANDS, and the countries bordering on the sea collectively.South AmericaCrops, Agricultural: Cultivated plants or agricultural produce such as grain, vegetables, or fruit. (From American Heritage Dictionary, 1982)Emigration and Immigration: The process of leaving one's country to establish residence in a foreign country.Organic Agriculture: Systems of agriculture which adhere to nationally regulated standards that restrict the use of pesticides, non-organic fertilizers, genetic engineering, growth hormones, irradiation, antibiotics, and non-organic ANIMAL FEED.Mediterranean SeaPacific OceanEcology: 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)Africa, Western: The geographical area of Africa comprising BENIN; BURKINA FASO; COTE D'IVOIRE; GAMBIA; GHANA; GUINEA; GUINEA-BISSAU; LIBERIA; MALI; MAURITANIA; NIGER; NIGERIA; SENEGAL; SIERRA LEONE; and TOGO.Genotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.Genealogy and HeraldryPopulation: The total number of individuals inhabiting a particular region or area.EuropePan paniscus: The pygmy chimpanzee, a species of the genus Pan, family HOMINIDAE. Its common name is Bonobo, which was once considered a separate genus by some; others considered it a subspecies of PAN TROGLODYTES. Its range is confined to the forests of the central Zaire basin. Despite its name, it is often of equal size to P. troglodytes.Africa, Central: The geographical area of Africa comprising CAMEROON; CENTRAL AFRICAN REPUBLIC; CHAD; CONGO; EQUATORIAL GUINEA; GABON; and DEMOCRATIC REPUBLIC OF THE CONGO.Passeriformes: A widely distributed order of perching BIRDS, including more than half of all bird species.Mimulus: A plant genus of the family Phrymaceae. Members contain 6-geranylflavanones and mimulone.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.Sorbus: A plant genus of the family ROSACEAE.Caves: Geological formations consisting of underground enclosures with access from the surface.Y Chromosome: The male sex chromosome, being the differential sex chromosome carried by half the male gametes and none of the female gametes in humans and in some other male-heterogametic species in which the homologue of the X chromosome has been retained.Animal Distribution: A process by which animals in various forms and stages of development are physically distributed through time and space.EcuadorMeliaceae: The mahogany plant family of the order Sapindales, subclass Rosidae, class Magnoliopsida.Altitude: A vertical distance measured from a known level on the surface of a planet or other celestial body.Cerebrovascular Circulation: The circulation of blood through the BLOOD VESSELS of the BRAIN.Wind: The motion of air relative to the earth's surface.Islands: Tracts of land completely surrounded by water.Campanulaceae: A plant family of the order Campanulales, subclass Asteridae, class MagnoliopsidaHerbicide Resistance: Diminished or failed response of PLANTS to HERBICIDES.Adaptation, Biological: Changes in biological features that help an organism cope with its ENVIRONMENT. These changes include physiological (ADAPTATION, PHYSIOLOGICAL), phenotypic and genetic changes.Coronary Circulation: The circulation of blood through the CORONARY VESSELS of the HEART.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.Fucus: A genus of BROWN ALGAE in the family Fucaceae. It is found in temperate, marine intertidal areas along rocky coasts and is a source of ALGINATES. Some species of Fucus are referred to as KELP.Rheology: The study of the deformation and flow of matter, usually liquids or fluids, and of the plastic flow of solids. The concept covers consistency, dilatancy, liquefaction, resistance to flow, shearing, thixotrophy, and VISCOSITY.Brassica rapa: A plant species cultivated for the seed used as animal feed and as a source of canola cooking oil.Cytochromes b: Cytochromes of the b group that have alpha-band absorption of 563-564 nm. They occur as subunits in MITOCHONDRIAL ELECTRON TRANSPORT COMPLEX III.LizardsAdaptation, Physiological: The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.Siberia: A region, north-central Asia, largely in Russia. It extends from the Ural Mountains to the Pacific Ocean and from the Arctic Ocean to central Kazakhstan and the borders of China and Mongolia.Sexual Behavior, Animal: Sexual activities of animals.Acanthaceae: A plant family of the order Lamiales. It is characterized by simple leaves in opposite pairs, cystoliths (enlarged cells containing crystals of calcium carbonate), and bilaterally symmetrical and bisexual flowers that are usually crowded together. The common name for Ruellia of wild petunia is easily confused with PETUNIA.Arabis: A plant genus of the family BRASSICACEAE. Member species are ornamentals grown for their numerous small white, yellow, pink, or purplish flowers.Agrostis: A plant genus of the family POACEAE.Environment: The external elements and conditions which surround, influence, and affect the life and development of an organism or population.Namibia: A republic in southern Africa, south of ANGOLA and west of BOTSWANA. Its capital is Windhoek.Conservation of Natural Resources: The protection, preservation, restoration, and rational use of all resources in the total environment.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.Anopheles: A genus of mosquitoes (CULICIDAE) that are known vectors of MALARIA.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.Principal Component Analysis: Mathematical procedure that transforms a number of possibly correlated variables into a smaller number of uncorrelated variables called principal components.Albizzia: A plant genus of the family FABACEAE that contains julibroside (triterpenoid saponins).Cactaceae: The cactus plant family of the order Caryophyllales, subclass Caryophyllidae, class Magnoliopsida. Cacti are succulent perennial plants well adapted to dry regions.Plants, Genetically Modified: PLANTS, or their progeny, whose GENOME has been altered by GENETIC ENGINEERING.Gastropoda: A class in the phylum MOLLUSCA comprised of SNAILS and slugs. The former have coiled external shells and the latter usually lack shells.Middle East: The region of southwest Asia and northeastern Africa usually considered as extending from Libya on the west to Afghanistan on the east. (From Webster's New Geographical Dictionary, 1988)Asia: The largest of the continents. It was known to the Romans more specifically as what we know today as Asia Minor. The name comes from at least two possible sources: from the Assyrian asu (to rise) or from the Sanskrit usa (dawn), both with reference to its being the land of the rising sun, i.e., eastern as opposed to Europe, to the west. (From Webster's New Geographical Dictionary, 1988, p82 & Room, Brewer's Dictionary of Names, 1992, p34)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.Optic Flow: The continuous visual field seen by a subject through space and time.Fagus: A plant genus of the family FAGACEAE.History, Ancient: The period of history before 500 of the common era.Abies: A plant genus in the family PINACEAE, order Pinales, class Pinopsida, division Coniferophyta. Balm of Gilead is a common name more often referring to POPULUS and sometimes to COMMIPHORA.
Panmixia: Panmixia (or panmixis) means random mating.King C and Stanfield W.Genetic variation: right|thumbMicrosatellite: 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.Health geography: Health geography is the application of geographical information, perspectives, and methods to the study of health, disease, and health care.Ethernet flow control: Ethernet flow control is a mechanism for temporarily stopping the transmission of data on Ethernet family computer networks. The first flow control mechanism, the PAUSE frame, was defined by the IEEE 802.Superficial velocity: Superficial velocity (or superficial flow velocity), in engineering of multiphase flows and flows in porous media, is a hypothetical (artificial) flow velocity calculated as if the given phase or fluid were the only one flowing or present in a given cross sectional area. Other phases, particles, the skeleton of the porous medium, etc.Hybrid inviability: Hybrid inviability is a post-zygotic barrier, which reduces a hybrid's capacity to mature into a healthy, fit adult.Hybrid inviability.Haplogroup L0 (mtDNA)Geolocation software: In computing, geolocation software is used to deduce the geolocation (geographic location) of another party. For example, on the Internet, one geolocation approach is to identify the subject party's IP address, then determine what country (including down to the city and post/ZIP code level), organization, or user the IP address has been assigned to, and finally, determine that party's location.Flow cytometry: In biotechnology, flow cytometry is a laser-based, biophysical technology employed in cell counting, cell sorting, biomarker detection and protein engineering, by suspending cells in a stream of fluid and passing them by an electronic detection apparatus. It allows simultaneous multiparametric analysis of the physical and chemical characteristics of up to thousands of particles per second.Genetic structure: Genetic structure refers to any pattern in the genetic makeup of individuals within a population.Phylogeography: Phylogeography is the study of the historical processes that may be responsible for the contemporary geographic distributions of individuals. This is accomplished by considering the geographic distribution of individuals in light of the patterns associated with a gene genealogy.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.Microevolution: Microevolution is the change in allele frequencies that occur over time within a population.Microevolution: What is microevolution?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.PollenGene pool: The gene pool is the set of all genes, or genetic information, in any population, usually of a particular species.Gibraltar MuseumEcosystemMolecular 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.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 asReproductive 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.F1 hybrid: An F1 hybrid (or filial 1 hybrid) is the first filial generation of offspring of distinctly different parental types. F1 hybrids are used in genetics, and in selective breeding, where it may appear as F1 crossbreed.In Memory of Celtic Frost: In Memory of... Celtic Frost is a Celtic Frost tribute album released in 1996.List of rivers in Western Sahara: This is a list of rivers in Western Sahara. This list is arranged north to south by drainage basin, with respective tributaries indented under each larger stream's name.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).Monarch Butterfly Biosphere ReserveThreshold 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.Biological dispersalInbreeding 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.Peat swamp forest: Peat swamp forests are tropical moist forests where waterlogged soil prevents dead leaves and wood from fully decomposing. Over time, this creates a thick layer of acidic peat.Lecythis ollaria: Lecythis ollaria is a species of treeBotryosphaeria corticola: Bot canker of oak is a disease on stems, branches and twigs of oak trees in Europe and North America. The casual agent of Bot canker of oak is the fungus Botryosphaeria corticola .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.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.Pinus pinasterTomato seed oil: Tomato seed oil is a vegetable oil extracted from the seeds of tomatoes.Athletics at the 2002 Central American and Caribbean GamesGene polymorphismAquila ItalianaFraxinus latifolia: Fraxinus latifolia (Oregon ash) is a member of the ash genus Fraxinus, native to western North America. The Oregon ash is dioecious.Makonde language: millionRanunculus abortivus: Ranunculus abortivus is a species of flowering plant in the buttercup family, Ranunculaceae. Its common names include littleleaf buttercup, small-flower crowfoot,Ranunculus abortivus.Natural Park of El FondoUtiaritichthys: Utiaritichthys is a genus of serrasalmid found in the Amazon and Orinoco basins in tropical South America.Plant breeders' rights: Plant breeders' rights (PBR), also known as plant variety rights (PVR), are rights granted to the breeder of a new variety of plant that give the breeder exclusive control over the propagating material (including seed, cuttings, divisions, tissue culture) and harvested material (cut flowers, fruit, foliage) of a new variety for a number of years.List of countries that regulate the immigration of felons: This is a list of countries that regulate the immigration of felons.Organic farming and biodiversity: The effect of organic farming has been a subject of interest for researchers. Theory suggests that organic farming practices, which exclude the use of synthetic pesticides and fertilizers, would be beneficial for biodiversity, and this has proven true.List of drainage basins by area: The list of drainage basins by area identifies basins (also known as watersheds or catchments), sorted by area, which drain to oceans, mediterranean seas, rivers, lakes and other water bodies. All basins larger than are included as well as selected smaller basins.Ecosystem of the North Pacific Subtropical Gyre: The North Pacific Subtropical Gyre (NPSG) is the largest contiguous ecosystem on earth. In oceanography, a subtropical gyre is a ring-like system of ocean currents rotating clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere caused by the Coriolis Effect.Spatial ecology: Spatial ecology is a specialization in ecology and geography that is concerned with the identification of spatial patterns and their relationships to ecological phenomena. Ecological events can be explained through the detection of patterns at a given spatial scale: local, regional, or global.Atomic heraldry: Atomic heraldry is heraldry characterised by the appearance of charges including the atom or showing the motion of parts of the atom; more loosely, it may describe heraldry in which atoms or the component parts thereof are represented through a combination of other charges. Obviously, this is a late development in heraldry.GA²LENRaiganj Wildlife SanctuarySkylark launch tower: A Skylark tower is a tower used for the launch of earlier versions of Skylark rockets. As Skylark rockets have no guidance system and accelerate slowly, they require a safe launch tower with a height of at least 24 metres with a guidance system.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.Bungonia Caves: Bungonia Caves is the name given to a series of caves near the city of Goulburn, New South Wales Australia.PCDHY: PCDH11Y is a gene unique to human males which competes with FOXP2 for the title of the "language gene." PCDH11Y is the gene for making Protocadherin 11Y, a protein that guides the development of nerve cells.Smoking in Ecuador: Smoking in Ecuador is more common among men and younger people. More than half of Ecuadorian smokers desire to quit.Trichilia catigua: Trichilia catigua is a flowering plant species in the genus Trichilia.Lake MarathonCerebral blood flow: Cerebral blood flow (CBF) is the blood supply to the brain in a given period of time.Tolias C and Sgouros S.Mountaineer Wind Energy Center: Mountaineer Wind Energy Center is a wind farm on Backbone Mountain in Preston and Tucker counties in the U.S.Pyrites Island: Pyrites Island () is the largest of three small islands lying northeast of Gam Point and forming the east side of Esther Harbor, off the north coast of King George Island in the South Shetland Islands. In 1913–14, the rocky extremity of Gam Point and the adjoining islands to the northwest and southeast were named Esther, Pyritis (sic) or Pyritic Islands by Scottish geologist David Ferguson, who reported they were composed of pyrites and vein quartz.Triodanis perfoliata: Triodanis perfoliata, the Clasping Venus's Looking Glass, is a flowering plant belonging to the family Campanulaceae. It is an annual herb native to North and South America, the natural range extending from Canada to Argentina.List of varieties of genetically modified maize: This is a partial list of varieties of maize that have been modified.Coronary perfusion pressure: Coronary perfusion pressure (CPP) refers to the pressure gradient that drives coronary blood pressure, meaning the difference between the diastolic aortic pressure and the right atrial diastolic pressure. It is a term used mainly in research concerning cardiac arrest.Coles PhillipsFucophlorethol AJournal of Rheology: Journal of Rheology is a peer-reviewed scientific journal publishing original (primary) research on all aspects of rheology, the study of those properties of materials which determine their response to mechanical force. It is published bimonthly by the Society of Rheology through the American Institute of Physics.Tokay gecko: The tokay gecko (Gekko gecko) is a nocturnal arboreal gecko, ranging from northeast India, Bhutan, Nepal, Bangladesh, throughout Southeast Asia, Philippines to Indonesia and western New Guinea. Its native habitat is rainforest trees and cliffs, and it also frequently adapts to rural human habitations, roaming walls and ceilings at night in search of insect prey.Maladaptation: 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.
(1/998) Speciation and gene flow between snails of opposite chirality.
Left-right asymmetry in snails is intriguing because individuals of opposite chirality are either unable to mate or can only mate with difficulty, so could be reproductively isolated from each other. We have therefore investigated chiral evolution in the Japanese land snail genus Euhadra to understand whether changes in chirality have promoted speciation. In particular, we aimed to understand the effect of the maternal inheritance of chirality on reproductive isolation and gene flow. We found that the mitochondrial DNA phylogeny of Euhadra is consistent with a single, relatively ancient evolution of sinistral species and suggests either recent "single-gene speciation" or gene flow between chiral morphs that are unable to mate. To clarify the conditions under which new chiral morphs might evolve and whether single-gene speciation can occur, we developed a mathematical model that is relevant to any maternal-effect gene. The model shows that reproductive character displacement can promote the evolution of new chiral morphs, tending to counteract the positive frequency-dependent selection that would otherwise drive the more common chiral morph to fixation. This therefore suggests a general mechanism as to how chiral variation arises in snails. In populations that contain both chiral morphs, two different situations are then possible. In the first, gene flow is substantial between morphs even without interchiral mating, because of the maternal inheritance of chirality. In the second, reproductive isolation is possible but unstable, and will also lead to gene flow if intrachiral matings occasionally produce offspring with the opposite chirality. Together, the results imply that speciation by chiral reversal is only meaningful in the context of a complex biogeographical process, and so must usually involve other factors. In order to understand the roles of reproductive character displacement and gene flow in the chiral evolution of Euhadra, it will be necessary to investigate populations in which both chiral morphs coexist. (+info)
(2/998) Macrogeographic population structure of the tsetse fly, Glossina pallidipes (Diptera: Glossinidae).
Tsetse flies are confined to sub-Saharan Africa where they occupy discontinuous habitats. In anticipation of area-wide control programmes, estimates of gene flow among tsetse populations are necessary. Genetic diversities were partitioned at eight microsatellite loci and five mitochondrial loci in 21 Glossina pallidipes Austin populations. At microsatellite loci, Nei's unbiased gene diversity averaged over loci was 0.659 and the total number of alleles was 214, only four of which were shared among all populations. The mean number of alleles per locus was 26.8. Random mating was observed within but not among populations (fixation index FST=0.18) and 81% of the genetic variance was within populations. Thirty-nine mitochondrial variants were detected. Mitochondrial diversities in populations varied from 0 to 0.85 and averaged 0.42, and FST=0.51. High levels of genetic differentiation were characteristic, extending even to subpopulations separated by tens and hundreds of kilometres, and indicating low rates of gene flow. (+info)
(3/998) Gene flow and hybridisation in a mixed oak forest (Quercus pyrenaica Willd. and Quercus petraea (Matts.) Liebl.) in central Spain.
Oaks are long-standing models for the study of gene flow and hybridisation. Temperate (Quercus petraea) and sub-Mediterranean (Quercus pyrenaica) oaks coexist in central Spain, showing remarkable differences in population size and structure. Q. petraea has a scattered distribution in central Spain, where it is at one of the southernmost limits of its range, and forms low-density stands; in contrast, Q. pyrenaica is widespread in the region. We selected a mixed population of the two species ( approximately 13 ha, 176 adults and 96 saplings) to compare the patterns of gene flow within each species and the extent of introgression between them. Using five nuclear microsatellite markers, we performed a parentage analysis and found considerable immigration from outside the stand ( approximately 38% for Q. petraea and approximately 34% for Q. pyrenaica), and estimated average seed-dispersal distances of 42 and 14 m for Q. petraea and Q. pyrenaica, respectively. Introgression between species was also estimated using our microsatellite battery. First, we developed a multivariate discriminant approach and, second, we compared our results with a widely used clustering method (STRUCTURE). Both analyses were consistent with a low level of introgression between Q. petraea and Q. pyrenaica. Indeed, only 15 adult trees, approximately 8.5%, were identified as putative hybrids when both methods of analysis were combined. Hybrids may be most common in contact zones due merely to physical proximity. (+info)
(4/998) Effect of gene flow on spatial genetic structure in the riparian canopy tree Cercidiphyllum japonicum revealed by microsatellite analysis.
Few studies have analyzed pollen and seed movements at local scale, and genetic differentiation among populations covering the geographic distribution range of a species. We carried out such a study on Cercidiphyllum japonicum; a dioecious broad-leaved tree of cool-temperate riparian forest in Japan. We made direct measurement of pollen and seed movements in a site, genetic structure at the local scale, and genetic differentiation between populations covering the Japanese Archipelago. Parentage analysis of seedlings within a 20-ha study site indicated that at least 28.8% of seedlings were fertilized by pollen from trees outside the study site. The average pollination distance within the study site was 129 m, with a maximum of 666 m. The genotypes of 30% of seedlings were incompatible with those of the nearest female tree, and the maximum seed dispersal distance within the study site was over 300 m. Thus, long-distance gene dispersal is common in this species. The correlation between genetic relatedness and spatial distance among adult trees within the population was not significant, indicating an absence of fine-scale genetic structure perhaps caused by high levels of pollen flow and overlapping seed shadows. Six populations sampled throughout the distribution of C. japonicum in Japan showed significant isolation-by-distance but low levels of genetic differentiation (F(ST) = 0.043), also indicating long-distance gene flow in C. japonicum. Long-distance gene flow had a strong influence on the genetic structure at different spatial scales, and contributes to the maintenance of genetic diversity in C. japonicum. (+info)
(5/998) Evidence for a one-allele assortative mating locus.
Theoretical models have shown that speciation with gene flow can occur readily via a "one-allele mechanism," where the spread of the same allele within both of two diverging species reduces their subsequent hybridization. Here we present direct genetic evidence for such an allele in Drosophila pseudoobscura. Alleles conferring high or low assortative mating in D. pseudoobscura produce the same effects when inserted into D. persimilis. This observation suggests that the type of genetic variation that is most conducive to controversial modes of speciation with gene flow, such as reinforcement or sympatric speciation, is present in nature. (+info)
(6/998) Genetic structure of Anopheles gambiae populations on islands in northwestern Lake Victoria, Uganda.
BACKGROUND: Alternative means of malaria control are urgently needed. Evaluating the effectiveness of measures that involve genetic manipulation of vector populations will be facilitated by identifying small, genetically isolated vector populations. The study was designed to use variation in microsatellite markers to look at genetic structure across four Lake Victoria islands and two surrounding mainland populations and for evidence of any restriction to free gene flow. METHODS: Four Islands (from 20-50 km apart) and two surrounding mainland populations (96 km apart) were studied. Samples of indoor resting adult mosquitoes, collected over two consecutive years, were genotyped at microsatellite loci distributed broadly throughout the genome and analysed for genetic structure, effective migration (Nem) and effective population size (Ne). RESULTS: Ne estimates showed island populations to consist of smaller demes compared to the mainland ones. Most populations were significantly differentiated geographically, and from one year to the other. Average geographic pair-wise FST ranged from 0.014-0.105 and several pairs of populations had Ne m < 3. The loci showed broad heterogeneity at capturing or estimating population differences. CONCLUSION: These island populations are significantly genetically differentiated. Differences reoccurred over the study period, between the two mainland populations and between each other. This appears to be the product of their separation by water, dynamics of small populations and local adaptation. With further characterisation these islands could become possible sites for applying measures evaluating effectiveness of control by genetic manipulation. (+info)
(7/998) Phylogeographic history and gene flow among giant Galapagos tortoises on southern Isabela Island.
Volcanic islands represent excellent models with which to study the effect of vicariance on colonization and dispersal, particularly when the evolution of genetic diversity mirrors the sequence of geological events that led to island formation. Phylogeographic inference, however, can be particularly challenging for recent dispersal events within islands, where the antagonistic effects of land bridge formation and vicariance can affect movements of organisms with limited dispersal ability. We investigated levels of genetic divergence and recovered signatures of dispersal events for 631 Galapagos giant tortoises across the volcanoes of Sierra Negra and Cerro Azul on the island of Isabela. These volcanoes are among the most recent formations in the Galapagos (<0.7 million years), and previous studies based on genetic and morphological data could not recover a consistent pattern of lineage sorting. We integrated nested clade analysis of mitochondrial DNA control region sequences, to infer historical patterns of colonization, and a novel Bayesian multilocus genotyping method for recovering evidence of recent migration across volcanoes using eleven microsatellite loci. These genetic studies illuminate taxonomic distinctions as well as provide guidance to possible repatriation programs aimed at countering the rapid population declines of these spectacular animals. (+info)
(8/998) Effective seed dispersal across a fragmented landscape.
The role of seed dispersal in maintaining genetic connectivity among forest fragments has largely been ignored because gene flow by pollen is expected to predominate. By using genealogical reconstruction, we investigated gene flow after establishment of seeds in a wind-pollinated, wind-dispersed tree. Our data show that seed dispersal is the main vector of gene flow among remnants and that long-distance dispersal is common across a chronically fragmented landscape. The relative importance of seed-mediated gene flow may have been underemphasized in other fragmented systems, and diagnosing the response of forest trees to current anthropogenic disturbances requires the assessment of phenomena after establishment. (+info)
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