What are the 4 major categories of evidence that taxonomists use to categorize organism evolution?

Fossils of the ancestors are basically used to classify the organisms. On the basis of that they identify the age and character of that organism so that they can relate to the exact organism.

Explanation:

the relative standard reduction potential of the half-cell in which reduction occurs; more positive than the other half-cell. reduction is a chemical process in which electrons are added to an atom or an ion; it always occurs accompanied by oxidation of the reducing agent.