This article is from the WSSF 2015 AFRMA Rat & Mouse Tales news-magazine.

An international team of scientists has identified 6 distinct lineages of the Black Rat (Rattus rattus). These originated in India, East Asia, the Himalayas, Thailand, the Mekong Delta, and Indonesia. The Indian lineage is the one that spread to the Middle-East, then later to Europe, Africa, the Americas, and Australia. This spread corresponds to the ancient routes of human migration.

Article Globetrotting Black Rat Genes Reveal Spread Of Humans And Diseases on ScienceDaily.