Final answer:
Evolutionary biology is the field that explains species relationships, summarizes the fossil record, and describes natural selection, utilizing systematics, taxonomy, and phylogenetics to hypothesize the evolutionary history of organisms.
Step-by-step explanation:
The field of study entails understanding how all species are related to each other, serving as a library of all life that has ever lived, summarizing the fossil record, and describing how natural selection works in evolutionary biology. Evolutionary biology encompasses systematics and taxonomy, which help organize and classify organisms. It integrates information from various sources, such as fossils, morphology, and genetic sequences, to build phylogenetic trees, providing hypothesized evolutionary relationships. Phylogenetic trees also get updated as new discoveries are made and new information comes to light, reflecting the evolving nature of scientific knowledge and the history of life on Earth.