Fig. 2.

A time-calibrated molecular phylogeny of Formica, Iberoformica, and Polyergus. Node bars indicate 95% highest posterior density. Scale is in millions of years. Abbreviations after taxa names indicate sample origin. Country codes follow the International Organization for Standardization (ISO) 3166: United States (US), Canada (CA), and Mexico (MX), in addition to noting state/province. Note single loss of independent colony foundation and gain of obligate DCF with inquilinism arising from within temporary parasites (yellow star). Taxon highlight colors signify species group membership; neogagates and fusca species groups are not monophyletic. Photographs are by April Nobile, Erin Prado, and Estella Ortega. Courtesy of https://www.antweb.org/.