316 • Technologies To Maintain Biological Diversity 



Species diversity: The number and variety of spe- 

 cies found in a given area in a region. 



Species richness: Areas with many species, espe- 

 cially the equatorial regions. 



Spectroscopy: Any of several methods of chemical 

 analysis that identify or classify compounds 

 based on examination of their spectral properties. 



Stochastic: Models, processes, or procedures that 

 are based on elements of chance or probability. 



Subspecies: A distinct form or race of a species. 



Taxon: A taxonomic group or entity (pi. taxa). 



Taxonomy: A hierarchical system of classification 

 of organisms that reflects the totality of similari- 

 ties and differences. 



Threatened species: A U.S. technical classification 

 referring to a species that is likely to become en- 

 dangered within the foreseeable future, through- 



out all or a significant portion of its range. These 

 species are defined as vulnerable taxa outside the 

 United States by the lUCN. 



Tissue culture: A technique in which portions of 

 a plant or animal are grown on an artificial cul- 

 ture medium in an organized (e.g., as plantlets) 

 or unorganized (e.g., as callus] state. (See also in 

 vitro culture.) 



Variety: See cultivar. 



Wild relative: Plant species that are taxonomically 

 related to crop species and serve as potential 

 sources for genes in breeding of new varieties 

 of those crops. 



Wild species: Organisms captive or living in the 

 wild that have not been subject to breeding to 

 alter them from their native state. 



Wildlife: Living, nondomesticated animals. 



