Julian Haynes Steward was an influential American anthropologist known for his work in the study of Native American cultures, particularly the Mogollon and Mimbres cultures of New Mexico. He developed the concept of 'cultural ecology,' which focuses on the relationship between human societies and their environment, highlighting how geography and resources shape cultural practices and societal development. His research provided valuable insights into the lifestyles, social organization, and environmental adaptations of these ancient cultures.