Sex-Biased Differences in Infant Mortality and Life Expectancy at Síi Túupentak, an Ancestral Ohlone Village in Central California (ca. 540–145 cal. BP)

Document Type

Article

Authors

Tammy Buonasera, University of California, DavisFollow
Jelmer Eerkens, University of California DavisFollow
Brian Byrd, Far Western Anthropological Research Group, Inc.Follow
Laurel Engbring, Far Western Anthropological Research Group, Inc.Follow
Monica V. Arellano, Muwekma Ohlone Tribe of the San Francisco Bay Area, Milpitas, CAFollow
Alan Leventhal, California State University, San JoseFollow
Glendon J. Parker, University of California, DavisFollow

Abstract

Síi Túupentak (CA-SCA-565/H) is a late precontact ancestral Ohlone village and cemetery site in Central California (ca. 540–145 cal. BP). Integration of proteomic, genomic, and osteological analyses provided highly confident biological sex estimates for remains of most individuals at this site (65 of 76), spanning all age groups, from perinatal infants to aged adults. Based on these relatively comprehensive data, it was possible to generate sex-specific Kaplan-Meier survival curves for this burial population of sedentary hunter-gatherers. As was common among societies predating modern Western medicine and antibiotics, infant mortality was high for both males and females. However, male infants (from birth to 5 years of age) appear to have died at nearly twice the rate of female infants (10 of 33 males vs. 5 of 32 females) and had a mean age of survival at birth of only 19 years, compared to 30 years for females. The difference in male and female survival was statistically significant by log-rank test (p = 0.005). Compared to survival curves for other societies predating modern Western medicine and antibiotics, including American-era historical deaths recorded for a cemetery in San Francisco, this bias is larger than might be expected. We suspect the pattern of sex-biased infant mortality at Síi Túupentak could relate to an intrinsic survival advantage for female infants, combined with extrinsic factors such as environmental pathogens, nutritional stress, and gendered differences in weaning patterns detected through stable isotope analyses. Using isotopic data on weaning ages and ethnographic accounts of gendered foraging activities, we focus on the potential role of sex-biased differences in weaning patterns and highlight potential demographic and social implications. Broader application of proteomic and genomic sex estimation would allow sex-biased differences in nutrition and health, as well as social and cultural aspects of male and female life histories, to be compared across a wide range of archaeologically known hunter-gatherer societies.

Recommended Citation

Buonasera, Tammy; Eerkens, Jelmer; Byrd, Brian; Engbring, Laurel; Arellano, Monica V.; Leventhal, Alan; and Parker, Glendon J. (2022) "Sex-Biased Differences in Infant Mortality and Life Expectancy at Síi Túupentak, an Ancestral Ohlone Village in Central California (ca. 540–145 cal. BP)," Human Biology: Vol. 94: Iss. 1, Article 4.
Available at: https://digitalcommons.wayne.edu/humbiol/vol94/iss1/4