Hierarchy.

For scholars, monks, and heredity-minded royal families, trees served as a handy way to divvy information into groups and sub-groups. Lima figures, "They had the concept of hierarchy in their minds and used the tree as a symbol for mapping because it was convenient. Over time, it became ingrained in our minds so that now when we talk about the root of a problem or describe genetics as a branch of science, we're really going back to this Medieval era when people started using diagrams to convey complex new knowledge."

CONNECT