Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
An illustration of subtree-neighbors The dotted subtrees could either be just one external node or a subtree of arbitrary size and topology. Species information is of no consequence for the concept of subtree-neighbors. The subtree-neighbors depicted here are for the default of k = 2.
