Sex-biased parental investment and female wealth accumulation in ancient California.

Objectives: The mortuary record at Middle Period site Kalawwasa Rummeytak (CA-SCL-134) (2600-1225 cal BP) in California's southern Santa Clara Valley shows pronounced wealth inequality; Olivella shell bead wealth, as well as other grave goods, are concentrated in the burials of several older adult females. The concentration of wealth among women, along with regional strontium isotopic evidence of male-biased residential shifts in early adulthood, suggests a matrilineal kinship system that practiced matrilocal post-marital residence patterns. We suggest local resource enhancement effects incentivized keeping women in their natal communities and investing more in female offspring.

Isotopic and genetic analyses of a mass grave in central California: Implications for precontact hunter-gatherer warfare.

Objectives: Analysis of a mass burial of seven males at CA-ALA-554, a prehistoric site in the Amador Valley, CA, was undertaken to determine if the individuals were "locals" or "non-locals," and how they were genetically related to one another.

Methods: The study includes osteological, genetic (mtDNA), and stable (C, N, O, S) and radiogenic (Sr) isotope analyses of bone and tooth (first and third molars) samples.

Results: Isotopes in first molars, third molars, and bone show they spent the majority of their lives living together.