Merritt Ruhlen (1944–2021) was a linguist and anthropologist, well known for his books Guide to the World’s Languages, Vol. 1: Classification (1987), The Origin of Language: Tracing the Evolution of the Mother Tongue (1994), On the Origin of Languages: Studies in Linguistic Taxonomy (1994), and numerous articles in journals, books, and encyclopedias. Ruhlen worked with Joseph H. Greenberg for three-and-a-half decades and became the principal advocate and defender of Greenberg’s methods of language classification. Ruhlen served as a lecturer in Anthropological Sciences and Human Biology at Stanford University, co-founder of the Evolution of Human Languages Project, advisor on the board of the Genographic Project, visiting professor at the City University of Hong Kong, and a Correspondant of the Museum National d’Histoire Naturelle in Paris. After a long illness Ruhlen succumbed on January 29, 2021 in his home in Palo Alto, Calif.