Final answer:
Anthropologists use taxonomy and phylogenetics to classify fossils by considering physical traits, relative ages, and speciation rates to understand evolutionary relationships.
Step-by-step explanation:
Anthropologists assign fossils to taxa, or categories in the biological classification system, by using a combination of taxonomy and phylogenetics. Taxonomy provides a hierarchical system for organizing and classifying fossils based on physical similarities and differences. This classification begins at a broad level with domains and progresses through kingdoms, phyla, classes, orders, families, genera, and finally to species. Paleoanthropologists often focus primarily on the phylum rank and are particularly interested in fossils of early humans (hominins) and other primates. Carolus Linnaeus is recognized for creating the basis of this taxonomic system.
To ascertain the relatedness of fossils and construct phylogenies, or evolutionary trees, scientists employ relative dating techniques to determine the geological ages of fossils, which can then inform them on the rate of speciation of early organisms. These relative dating techniques, alongside detailed anatomical studies of fossil remains, provide evidence that helps to correctly classify fossils within the taxonomic ranks and draw conclusions regarding genetic relationships and ancestries.