Glossary biotechnology There is current debate over the role of GMOs in agriculture Genetic architecture A characterization of the number and types of genes that underlie a particular trait, and their interactions Genetic code The language that specifies how DNA will be translated into amino acid sequences by means of three nucleotide ‘‘words’’ (codons) that specify the 20 amino acids and regulators of transcription (start and stop codons) Genetic diversity Genetic variety found within or among species; this allows the population or species to adapt and evolve in response to changing environments and natural selection pressures Genetic drift The process of random changes in gene frequency, leading to changes in the genetic composition of a population The effect of this process is particularly important in small population sizes Genetic erosion A loss of genetic diversity in a species, often caused by anthropogenic factors such as land clearing or urbanization Genetic load The extent to which an individual is inferior to the best possible individual in the population in terms of fitness, as a consequence of the genes it contains Genetic recombination The physical exchange of genetic material between a pair of chromosomes during meiosis Genetic variation Differentiation in traits that is attributable to genetic differences among the individuals in a population Genetics The scientific study of genes, in the context of an individual cell or organism, the passing of genes from parent to offspring, and the distribution, variation, and alteration of genes in populations Genome The complete set of genes of an individual organism Genomic Having to with the genome (see previous) Genomic cluster See GENOTYPIC CLUSTER Genomics The discipline of genetics that focuses on the study of the complete genetic content of species, often by determining the entire DNA sequence of organisms and the expression and function of their genes in relation to various stimuli or metabolic perturbations Genotype The genetic makeup of an organism Compare PHENOTYPE Genotypic Relating to the genetic composition of an organism Genotypic cluster In a local area, a single group of individuals recognizable on the basis of multiple, unlinked inherited characters or genetic markers Gentes (singular gens) Brood parasite species with a hostspecific lineage Specifically, lineages of cuckoos in which individual females specialize on a single host and lay mimetic eggs Geographic information system (GIS) Any of various computational systems for storing, managing, manipulating, and displaying spatial data Because landscape models are inherently spatial, strong links to GIS are either built into such models or are required to interface with the model’s data Geomorphological Having to with or used in geomorphology (see next) 505 Geomorphology The study of the surface configuration of the Earth, especially the nature and evolution of current land forms, their relationships to underlying structures, and the history of geological activity as represented by such surface features Geophyte A plant with succulent storage tissues such as bulbs, corms, or rhizomes Geospatial Having to with locations on the Earth Geothermal Having to with or produced by the internal heat that exists below the surface of the Earth Thus, geothermal energy, geothermal heat(ing) Germplasm Sources of hereditary material In animal breeding, the breeding animals and fresh or frozen sperm cells, ova, and embryos GHG greenhouse gas ghost fishing A term for the fact that lost, discarded, or abandoned fishing gear (such as ghost nets) can still continue to catch fish Gini–Simpson index An index that quantifies the probability that two entities (such as individuals) drawn at random from the data set represent different types (such as species) Often used as a diversity index, but not an expression of diversity itself [Named for the statisticians C W Gini and E H Simpson.] GIS Geographic information system Global Biodiversity Assessment (GBA) An independent, peer-reviewed analysis of the biological and social aspects of biodiversity, commissioned by the United Nations Environment Programme Global change disturbance An alteration or disturbance significant enough to have global impact on the natural conditions of the atmosphere (such as GHGs produced by human activities), or on various regions throughout the world (such as large-scale deforestation or the widespread introduction of exotic, invasive species) Global circulation The regular circulation pattern of the Earth’s atmosphere, which generates the world’s basic climate types; the system involves an Intertropical Convergence zone of low pressure near the equator, subtropical high-pressure belts near the Tropics of Cancer and Capricorn, trade winds flowing from these high-pressure belts toward the equatorial low, and westerly winds in the middle latitudes Global climate change See CLIMATE CHANGE Global Environment Facility (GEF) An independent financial organization providing grants to developing countries and countries with economies in transition, for projects related to biodiversity, climate change, international waters, land degradation, the ozone layer, and persistent organic pollutants Global environmental sustainability See ENVIRONMENTAL SUSTAINABILITY Global extinction The fact of a species becoming extinct worldwide, as opposed to local extinction which applies to a particular area Globalization The process in which businesses and financial markets operate internationally, or increase the extent to which they so, largely as a result of increased trade, transportation, and communications Global warming The warming trend of the Earth’s surface temperatures from the late 19th century onward and