Define Biosystematics - Animal Taxonomy

Biosystematics is basically synonymous with systematic, though it places more emphasis upon genetic (concerning inheritance) and cytological data (concerning cell function and structure) rather than upon morphological, anatomical physiological or spatial information, alone. It tries to infer evolutionary relationships with the study of reproductive compatibility and gene flow. Biosystematics assess the genetic variation in population and among species. Using information from their genetic studies, biosystematics make inference about the ancestral history of a species and thus study speciation (the evolution of one species into two).

They collect data on variation in a population of organisms and then analyse the data in order to construct a model of genetics of the population. For instance, in Winconsin, a single population of fly maggots has begun to feed, mature and then reproduce near either apple or cherry trees. As these two types of trees bear fruits at different time of the year, the apple eating maggots and the cheery eating maggot may at one point of time become reproductively isolated from one another. A biosystematics might infer that in this case speciation is occurring.