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.
Temporal patterns. a) Changes in most probable ancestral state (L1, L2, or L34) of human RNA virus genera estimated using sequences from species/types discovered before cutoff date shown. b) As a) showing fractions. c) Changes in the numbers of distinct human-infective RNA virus lineages (human transmissible, strictly zoonotic, or mixed) estimated using sequences from species/types discovered before cutoff date shown. d) As c) showing fractions.
