"When linguists talk about the historical relationship between languages, they use a tree metaphor. An ancient source (say, Indo-European) has various branches (e.g., Romance, Germanic), which themselves have branches (West Germanic, North Germanic), which feed into specific languages (Swedish, Danish, Norwegian). Minna Sundberg, creator of the webcomic Stand Still. Stay Silent, a story set in a lushly imagined post-apocalyptic Nordic world, has drawn the antidote to the boring linguistic tree diagram."
Via Seth Dixon