GENE: The basic physical unit of heredity consisting of a DNA sequence at a specific location on a chromosome.
GENE MAP: Also a linkage map or chromosome map. A diagram showing the chromosomal locations of specific genetic markers and genes of interest.
GENERATION INTERVAL: (1) The amount of time required to replace one generation with the next. (2) In a closed population, the average age of parents when their selected offspring are born.
GENETIC PREDICTION: The area of academic animal breeding concerned with measurement of data, statistical procedures, and computational techniques for predicting breeding values and related values.
GENETIC TREND: Change in the mean breeding value of a population over time.
GENETIC VARIATION: In the context of the key equation for genetic change, variability of breeding values within a population for a trait under selection.
GENOTYPE: (1) The genetic makeup of an individual. (2) The combination of genes at a single locus or at a number of loci. Geneticists speak of one-locus genotypes, two-locus genotypes, and so on.
GENOTYPIC VALUE: The effect of an individual's genes (singly and in combination) on its performance for a trait.
GREASY ALPACA FLEECE: A commercial term identifying unwashed alpaca fleece.
GUANACO: A wild member of the New World camelidae family, Lama gunaimicoe.
GUARD HAIR: Also kemp. Coarse medulated fiber. A second coat of fiber found in llamas, vicuna, guanacos, and, to a lesser degree, alpacas.
HACIENDA: A large land holding that originated with the land grant system used by Spanish conquistadores. In size, comparable to an American plantation.
HALF SIBS: Half brothers and sisters.
HEMBRA: Female alpaca or animal.
HERITABILITY: A measure of the strength of the relationship between performance (phenotypic values) and breeding values for a trait in a population. Heritability in the broad sense.
HISTOGRAM: (1) The most common graphical presentation of quantitative data. The variable of interest, such as fiber diameter measured in microns, is placed on the horizontal axis and the frequency values, such as the percentage of fibers per micron, are placed on the vertical axis. (2) A micron test report that includes administrative information provided by the identification sent in with the individual sample. The histogram on such a report depicts the measurement of 2000 fibers in scale.
HUACAYA: A breed of alpaca characterized by a well-crimped fleece that grows perpendicular to the skin.
HUARIZO: A crossbred animal. A term most often used to describe a llama-alpaca cross. Characterized by weak, medulated fiber and poor breed type.
HYBRID: An individual that is a combination of species, breeds within species, or lines within breeds.
HYBRID VIGOR: An increase in the performance of hybrids over that of purebreds, most noticeably in traits such as fertility and survivability.
INBREEDING: The mating of relatives.
INBREEDING CO-EFFICIENT: The measure of the level of inbreeding in an individual determined by (1) the probability that both genes of a pair in an individual are identical by descent, or (2) the probable proportion of an individual's loci containing genes that are identical by descent.
INBREEDING DEPRESSION: The reverse of hybrid vigor. A decrease in the performance of inbreds, most noticeably in traits such as fertility and survivability.
INDEPENDENT CULLING LEVELS: Minimum standards for traits undergoing multiple trait selection. Animals failing to meet any one standard are rejected regardless of merit in other traits.
INDICATOR TRAIT: A trait that may or may not be important in itself, but is selected for as a way of improving some other genetically correlated trait.
INDIRECT SELECTION: Selection for one trait as a means of improving a genetically correlated trait.