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)
