What is a phylogenetic tree and what information does it convey?

A phylogenetic tree is a branching diagram that represents evolutionary relationships among organisms, genes, or proteins based on similarities and differences in their sequences or characteristics. Key components include: leaves/tips (representing current species or sequences), branches (representing evolutionary lineages), nodes (representing common ancestors), and branch lengths (often representing evolutionary distance or time). Trees can be rooted (with a defined ancestor) or unrooted. Phylogenetic analysis helps understand evolutionary history, predict gene function, and classify organisms.