Glossary of terminology

 

adaptation:
1: The process of adjustment of an individual organism to environmental stress; adaptability;
2: Process of evolutionary modification which results in improved survival and reproductive efficiency;
3: Any morphological, physiological, developmental or behavioral character that enhances survival and reproductive success of an organism

agroecosystem: an agricultural ecosystem: row crop (i.e. corn), solid planted crop (i.e. wheat), perennial forage, managed forest, rangeland, etc.; crop rotation

agroecotype
: an edaphic ecotype adapted to cultivated soils

biodiversity. 1: the absolute number of species in a community, species richness; 2: a measure of the number of species and their relative abundance in a community; 3: the condition of having differences with respect to a given character or trait

biotype: an intra-specific group of genetically identical individuals distinguishable by biochemical characters

ecology: the study of the interrelationships between living organisms and their environment

ecosystem
: a community of organisms and their physical environment interacting as an ecological unit; the entire biological and physical content of a biotope

ecotype
:
1: a locally adapted population; a race or infraspecific group having distinctive characters which result from the selective pressures of the local environment; ecological race;
2: a subunit capable of interbreeding with members of that and other ecotypes q.v. comprising individuals capable of interbreeding with members of that and other ecotypes within the ecospecies but remaining distict through selection and isolation;
3: biotype

evolution

1: Any gradual directional change, unfolding;
2: Any cumulative change in the characteristics of organisms or populations from generation to generation; descent or development with modification;
3: change in the frequency of genes in a population

fitness: the relative competitive ability of a given genotype conferred by adaptive morphological, physiological or behavioral characters, expressed and usually quantified as the average number of surviving progeny of one genotype compared with the average number of surviving progeny of the competing genotypes

genetic polymorphism: the long-term occurrence in a population of two or more genotypes in frequencies that cannot be accounted for by recurrent mutation the co-occurrence of two or more alleles at the same locus in a population at frequencies that cannot be accounted for by recurrent mutation alone

genotype:
1: The hereditary or genetic constitution of an individual; all the genetic material of a cell, usually referring only to the nuclear material; the genetic constitution of an organism, as distinguished from its physical appearance (phenotype)
2: All individuals sharing the same genetic constitution; biotype;
3: The specimen on which a genus-group taxon is based; the primary type of the type species

habitat: the locality, site and particular type of local environment occupied by an organism

hybridization: any crossing of individuals of different genetic compostion, typically belonging to separate species, resulting in hybrid offspring

introgression: the spread of genes of one species into the gene pool of another by hybridization and backcrossing; introgressive hybridization

mutant: any organism, gene, or character that has undergone mutational change; an organism bearing a mutant gene that expresses itself in the phenotype of the organism

natural selection:
1: the non-random and differential reproduction of different genotypes acting to preserve favorable variants and to eliminate less favorable variants;
2: viewed as the creative force that directs the course of evolution by preserving those variants or traits best adapted in the face of natural competition
3: essence of theory of evolution by natural selection is that genotypes with higher fitness leave a proportionately greater number of offspring, and consequently their genes will be present in a higher frequency in the next generation

niche
: the ecological role of a species in a community; conceptualized as the multidimensional space, of which the coordinates are the various parameters representing the condition of existence of the species, to which it is restricted by the presence of competitor species; sometimes used loosely as an equivalent of microhabitat in the sense of the physical space occupied by a species

phenotype:
1: The sum total of observable structural and functional properties of an organism; the product of the interaction between the genotype and the environment;
2: the observable properties of an organism, produced by the genotype in conjunction with the environment

plasticity: The capacity of an organism to vary morphologically, physiologically or behaviorally as a result of environmental flucuations
reaction type

population
:
1: all individuals of one or more species within a prescribed area;
2: a group of organisms of one species, occupying a defined area and usually isolated to some degree from other similar groups

population biology
: Study of the spatial and temporal distributions of organisms

population genetics
: Study of gene frequencies and selection pressures in populations

somatic polymorphism. 1: the production of plant parts (leaves, seeds, etc.) of different morphologies or behavior on different parts of the same plant; 2: not genetic segregation but a somatic differentiation; 3: two distinct phases of growth of an individual plant, each adapted to a specific season (seasonally dimorphic phenotype)

speciation:
1: The formation of new species;
2: the splitting of a phylogenetic lineage;
3: acquistion of reproductive isolating mechanisms producting discontinuities between populations;
4: process by which a species splits into 2 or more species

species:
1: A group of organisms, minerals or other entities formally recognized as distinct from other groups;
2: a taxon of the rank of species; in the hieracrchy of biological classification the category below genus; the basic unit of biological classification; the lowest principal category of zoological classification
3: A group of morhologically similar organisms of common ancestry that under natural conditions are potentially capable of interbreeding
4: A species is a group of interbreeding natural populations that are reproductively isolated from other such groups

species-Group: a group of closely related species, usually with partially overlapping ranges; sometimes used as an equivalent of superspecies

superspecies: a monophyletic group of entirely or essentially allopatric (occupying different geographic areas) species that are considered to be too distinct morphologically to be regarded as a single species

variant: any individual or group showing marked deviation from type, in form, quality or behavior; an individual that is different from an arbitrary standard type (usually the wild type)

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