Curator of Anthropology Dr. John Johnson has a reputation for asking hair-raising questions. Over the past five years, John has collected more than 100 hair follicle samples as part of his research into the genetic relationships among California Indian tribes belonging to different linguistic families.
Before European contact, California had one of the most diverse populations of Native Americans anywhere in the country. Over 60 different languages were spoken within a vast patchwork of different cultural groups. How closely were these groups related to one another? Did intermarriage result in genetic similarities or did some populations maintain their genetic distinctions? How can such questions from the past be answered today?
Found in the chromosomes of all living cells, nuclear deoxyribonucleic acid (DNA) transmits hereditary information from parents to children. Outside the nucleus of the cell exist mitochondria that convert food to energy and also contain a DNA molecule which is inherited only along female lines, mother to daughter. By examining the mitochondrial DNA of Chumash living today, John hopes to gather clues regarding the genetic prehistory of the Chumash Indians who lived in south central California and determine if they were genetically distinct from other neighboring tribes.
John has collaborated with Dr. Joseph Lorenz at the Genetic Testing Laboratory in Colorado. Emerging from their work are a few tantalizing glimpses of Chumash genetic ancestry. The vast majority of American Indians belong to four mitochondrial groups (A through D) known as clades. A clade is a group of related genetic lineages that descend from a common ancestor. The founding populations of the Americas appear to have been relatively small and to have originated in Asia. The same four clades present among Native Americans are still found in East Asia.
Working with Chumash descendants whose family ancestries were established through Mission records and other sources, John located 13 surviving mitochondrial lineages. With permission from descendants, hair follicle samples were first screened to see into which clade they would fall. The results indicate that three Chumash samples within Clade A may be traced back to women living in widely separated villages at the time of Spanish contact. Although they differed slightly, these three Chumash lineages were more closely related to each other than to any other Clade A lineages in the Americas.
John's research provides a window into the past through which we see the first hint of genetic relationships among Chumash populations. The slight degree of variation in mitochondrial lineages may be the result of slowly accumulating genetic change over a long period of time. If this initial observation is supported by further research, it attests to great antiquity for Chumash presence within the Santa Barbara region.
[Originally published in Santa Barbara Museum of Natural History Annual Report 1995, pp. 2-3]
John R. Johnson is curator of Anthropology for the Santa Barbara Museum of Natural History. For questions or comments send e-mail to the following address: firstname.lastname@example.org