Tree Bisect and Reconnect

Tree bisection and reconnection is an operation performed on a phylogenetic tree. A subtree is pruned and then reattached by connecting some edge on the subtree to some edge of the original tree. Unlike in a subtree prune and regraft operation, the reattached subtree need not be reattached at its root. When performing a search of a space of phylogenetic trees in an optimization problem, a reconnection that follows a bisection pruning a large subtree—as has happened to this valley oak—can enable the search to explore a distant part of the tree space.

Photo: Noah Rosenberg, April 14, 2018