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ABSTRACT: Stable carbon and nitrogen isotope analyses of bones and teeth at the ancestral heritage Muwekma Ohlone site of Yakmuy ́Ooyákma-tka (“Place of the East Ridge Site”; CA-SCL-215) reveal significant differences in the dietary life history of males and females. Overall, isotope data indicate that site inhabitants were primarily dependent on low-trophic-level foods, likely plants, and minor amounts of marine food for their main source of dietary protein. From tooth dentin serial samples, we found that males and females were similar for δ13C in early childhood (age 1–9 years), but boys were elevated in δ15N by 0.6–1.0‰ relative to girls, indicating boys were accessing slightly greater amounts of higher-trophic-level foods, such as meat from game. The sex-biased difference in δ15N diminishes during the second decade of life, as female δ15N values increase and become equal to males. However, a difference in δ13C emerges during the second decade: female δ13C values are elevated relative to males. This could indicate that teenage females consumed higher amounts of low-trophic-level, marine-derived protein, such as shellfish. During later adult years the difference in δ13C disappears, while males again show an increase in δ15N relative to females. Although these differences are small, they reveal important sex-biased life history patterns during childhood and adulthood in this ancient community. 

Traditional knowledge, along with archaeological and linguistic evidence, documents that California supports cultural and linguistically diverse Indigenous populations. Studies that have included ancient genomes in this region, however, have focused primarily on broad-scale migration history of the North American continent, with relatively little attention to local population dynamics. Here, in a partnership involving researchers and the Muwekma Ohlone tribe, we analyze genomic data from ancient and present-day individuals from the San Francisco Bay Area in California: 12 ancient individuals dated to 1905 to 1826 and 601 to 184 calibrated years before the present (cal BP) from two archaeological sites and eight present-day members of the Muwekma Ohlone tribe, whose ancestral lands include these two sites. We find that when compared to other ancient and modern individuals throughout the Americas, the 12 ancient individuals from the San Francisco Bay Area cluster with ancient individuals from Southern California. At a finer scale of analysis, we find that the 12 ancient individuals from the San Francisco Bay Area have distinct ancestry from the other groups and that this ancestry has a component of continuity over time with the eight present-day Muwekma Ohlone individuals. These results add to our understanding of Indigenous population history in the San Francisco Bay Area, in California, and in western North America more broadly. 

Abstract Sex estimation of skeletons is fundamental to many archaeological studies. Currently, three approaches are available to estimate sex–osteology, genomics, or proteomics, but little is known about the relative reliability of these methods in applied settings. We present matching osteological, shotgun-genomic, and proteomic data to estimate the sex of 55 individuals, each with an independent radiocarbon date between 2,440 and 100 cal BP, from two ancestral Ohlone sites in Central California. Sex estimation was possible in 100% of this burial sample using proteomics, in 91% using genomics, and in 51% using osteology. Agreement between the methods was high, however conflicts did occur. Genomic sex estimates were 100% consistent with proteomic and osteological estimates when DNA reads were above 100,000 total sequences. However, more than half the samples had DNA read numbers below this threshold, producing high rates of conflict with osteological and proteomic data where nine out of twenty conditional DNA sex estimates conflicted with proteomics. While the DNA signal decreased by an order of magnitude in the older burial samples, there was no decrease in proteomic signal. We conclude that proteomics provides an important complement to osteological and shotgun-genomic sex estimation.