2.20.97
Biology & Ecology
bglossary.html
Unit 1: Glossary of terminology
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
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
genotype:
1: The hereditary or genetic constitution of an individual; all the genetic
material of a cell, usually referring only to the nuclear material;
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
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: The sum total of observable structural and functional properties
of an organism; the product of the interaction between the genotype and
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
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
species-group: A group of closely related species, usually with
partially overlapping ranges; sometimes used as an equivalent of superspecies.
weed:
1: anthropomorphic (plants relationship to us as humans); tells us something
about how we view nature;
2: "a plant out of place" (WSSA, 1956);
3: "competitive and aggressive behavior" (Brenchley, 1920);
4: "persistance and resistance to control" (Gray, 1879);
5: "useless, unwanted, undesirable" (Bailey, 1941);
6: "a plant whose virtues have not yet been discovered" (Emerson,
1878);
7: "appearing without being sown or cultivated" (Brenchley, 1920);
8: "a plant that grows spontaneously in a habitat greatly modified
by human action" (Harper, 1944);
9: "unsightly" (Thomas, 1956)
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
allele: any of the different forms of a gene occupying the same locus
(q.v. on homologous chromosomes), and which undergo meiotic pairing (q.v.
and can mutate one to another)
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 competing
genotypes; a measure of the contribution of a given genotype to the subsequent
generation relative to that of other genotypes.
genotype:
1: The hereditary or genetic constitution of an individual; all the genetic
material of a cell, usually referring only to the nuclear material;
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
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: The sum total of observable structural and functional properties
of an organism; the product of the interaction between the genotype and
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
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.
