1) Biosystematy 2) Systematics 1) Biosystematy 
[n] - use of data (e.g. cytogenetic or biochemical) to assess taxonomic relations especially within an evolutionary framework
biosystematics 1. A botanical term designating the systematic study of populations and species, especially by means of ecological or experimental methods. 2. The study of the relationships among groups of species using criteria such as morphology, biochemistry, and DNA comparisons, especially to determine the evolutionary history of a species (use...
biosystematy noun use of data (e.g. cytogenetic or biochemical) to assess taxonomic relations especially within an evolutionary framework