Phylogeny is the study of the evolutionary history and relationships among different species or groups of organisms. It helps scientists understand how species have evolved over time and how they are related to one another. This is often represented in a diagram called a phylogenetic tree, which illustrates the branching patterns of evolution. By analyzing genetic, morphological, and behavioral traits, researchers can construct these trees to show common ancestors and divergence points. Phylogeny is essential in fields like taxonomy, ecology, and conservation biology, as it provides insights into biodiversity and the evolutionary processes that shape life on Earth.