Which scientific area is a major force in shaping modern classification methods? physiology anatomy evolution behavior regions

This is evolution.

Explanation:

Based on the system of Cladistics,some systematists are basing organism classification on the period in which they appear  or evolved on earth.Therefore  species of organism which evolved first are said to be the early organism, and appear higher in the level of classification,while those that evolved later are lower to these organisms in the evolutionary tree.

Simply put,Evolution refers to the progression of changes in an organism overtime.It is as a result of the ability of  species of organism to withstand  the selective pressure because of the presence of certain inheritable adaptive traits, compare to other organisms in the population.The organisms with these traits are naturally selected.

Therefore, the species of organism with the ability to evolved due to natural selection,are placed  higher in the classification tree, while other organisms which evolved later,thus with lesser resistance to the  selection pressure are placed below.

Therefore if these traits  is in their DNA ,and  are responsible for evolution,then classification based on evolution helps to understand the hierarchy  by which different organism species appear.Hence evolution and classification are related.