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Bay area bioarchaeology

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Daoshi Tsuruchi
Daoshi Tsuruchi

This document summarizes an analysis of skeletal remains from three archaeological sites in the San Francisco Bay Area: SFr-7, Ala-342, and Ala-329. The analysis compared dental attrition, vertebral osteophytosis, cranial trauma, and post-cranial trauma between the sites. Differences in dental attrition and vertebral osteophytosis were likely due to differences in diet and environment between coastal and inland sites. Rates of cranial and post-cranial trauma varied between sites and samples, but were inconclusive about levels of interpersonal violence due to small sample sizes and poor provenience of remains. More research is needed to make accurate comparisons between sites over time.

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Bay Area Bioarchaeology By Daniel Villanueva
Thesis Question Archaeologists dont always have the luxury of large sample sizes, especially when looking at pre-historic populations from San Francisco. When comparing small samples to larger ones, when are differences between the samples due to actual differences between the populations, and when are differences due to sampling error?
Sources CA-SFr-7 N=28 CA-Ala-342 N=42 CA-Ala-329 N=167, N=365 Various sites (CA-CCo-138, CA-YOL-13, ?, Etc.) N=42
Dental Attrition Dental attrition for adult individuals from SFr-7 ranged from stage 2 to stage 4, with dental attrition first becoming evident in young adults (Rudo 1982). In comparison, dental attrition for individuals from Ala-342 range from stage 3 to stage 8, with dental attrition first becoming evident at 3 years of age (Jurmain 1983). There are no individuals from SFr-7 between the ages 3-15 years of age. While no dental carries were present in any individuals from SFr-7, apical abscesses were common (Rudo, 1982).
Vertebral Osteophytosis Vertebral osteophytosis (VOP) is the development of degenerative lesions between the fibrocartilagenous joints of the vertebral column (Jurmain, 1990). At SFr-7, VOP affected 30% of the adult population, occurred exclusively in individuals past the age of thirty, and had no apparent correlation with gender or mode of burial. At Ala-342, VOP affected 85.7% of the adult population, manifesting as early as 16-23 years of age.
Vertebral Osteophytosis Ala-329 SFr-7 N=92-138 N=? C-M 55.7% 10% C-S 28.9% 10% C-A 4.7% 5% T-M 59.7% 10% T-S 25.3% 5% T-A 2.6% 5% L-M 77.6% 10% L-S 68.4% 20% L-A 3.9% 25% (Jurmain, 1990)
2 individuals from SF-7, a male and a female between the ages of 21-25, displayed possible cranial trauma (Rudo, 1982). Assuming that this assessment is correct, the frequency of cranial trauma among adults at SFr-7 would be 10%. Cranial Trauma 8 out of 365 individuals from Ala-329, displayed some sort of cranial trauma (2.2% of sample). 7 cases came from the 260 adults from the site (2.7% of adults) All instances of cranial trauma were found in males (5.2% of the male sample) (Jurmain, 1997). A 23-30 year old male was the only individual out of 42 from Ala-342 that displayed a depressed cranial fracture (2.3% of sample). Among adults, the frequency of cranial trauma would be 7.1% Among adult males, this frequency would be at 14.3%
Cranial Trauma Cranial depressions are not necessarily indicative of interpersonal violence. Out of all three samples, only one skull from Ala-329 reported a cranial trauma with an imbedded obsidian fragment. All reported depression fractures from Ala-342 and Ala-329 showed signs of healing.
Post-Cranial Trauma Individuals from the counties of Sacramento, Yolo, Alameda, Contra Costa, and some from unknown origin were pooled together for an analysis of interpersonal violence in the San Francisco bay-area/Central California (Gabet, 1997). Most points fell into two distinct groups based on length and width. Relatively larger points presumably belonged to spears, while the majority of points from this sample were from the smaller cluster that may have been attached to arrows (Gabet, 1997)
Post-Cranial Trauma
Post-Cranial Trauma The higher frequency of injuries on the left side of the body may suggest right-handed archery (Gabet, 1997). The higher frequency of injuries along the central axis of the body may suggest that archers were taking precise shots at their targets (Gabet, 1997). 30 of the 42 individuals used for this analysis were adult males. Nearly all males displayed some sort of healing after injury, although this did not necessarily mean that the individual did not eventually die from infection.
Conclusions Error: SFr-7 was not entirely excavated, and is only one of ten to twelve midden sites along Visitation Valley and Hunters Point. The complete absence of individuals from ages 3-15, suggest that perhaps some individuals were buried elsewhere, or may have been cremated. Furthermore, the top four feet of the site was destroyed prior to excavation, most likely due to weather. Ala-329 may have been utilized by more than one village group. This may explain the large amount of individuals buried at this site, and may skew the meaning of cranial trauma and VOP frequencies. Ala-342 displayed a number of disassociated bones. Some bones could be reasonably attributed to nearby burial lots. The remainder of bones belonged to a maximum of 13 individuals. Without the sample sizes from each site, it is impossible to determine the frequencies of interpersonal violence on a site-to-site basis. Two individuals from YOL-13 displayed four or more projectile wounds, and nearly 村th of all projectile wounds came from CCo-138.
Conclusions Dental Attrition: Individuals from Ala-342 may exhibit more severe dental attrition than those from SFr-7 due to diet. Ala-342 is located further inland, where acorns, hard nuts and seeds would have made up a large portion of the diet. While seeds and tubers would have been part of the diet at SFr-7, faunal analysis suggests that shellfish, deer, sea-otter, fish, and waterfowl would have been a more readily available resource. The practice of chewing lime with tobacco may also have contributed to dental attrition (Knott, 1979).
Conclusions Vertebral Osteophytosis: The pattern of VOP at SFr-7 suggest that the primary caused of VOP was aging. While not all old individuals exhibited VOP, Rudo did not specify whether VOP was not scored due to absence of the pathology, or the absence of vertebral elements. This may explain why there is a high frequency of Ankylosis, with low frequencies of moderate to severe VOP.
Conclusions Cranial Trauma: Cranial trauma from SFr-7 cannot be definitively correlated to interpersonal violence. Cranial trauma from Ala-342 and Ala-329 may have been due to interpersonal violence, as all instances were in males. However, these injuries may also be a result of accidents while hunting. Only the skull with the imbedded projectile from Ala-329 can confidently be attributed to interpersonal violence.
Conclusions Post-Cranial Trauma: No post-cranial trauma attributable to interpersonal violence was found at SFr-7. However, the burial of a female with an associated projectile point suggests she was the victim of interpersonal violence, as no other projectile points were present at SFr-7. This individual also displayed a cranial fracture.
Provenience of Archaeological Elements at SFr-7
Conclusions More research is necessary to make more accurate conclusions about the people that lived near SFr-7. It is also important to make distinctions not only by location, but by temporality. VOP, instances of interpersonal violence, and dental attrition may be concentrated or absent during specific time periods.
THE END

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Bay area bioarchaeology

  • 1. Bay Area Bioarchaeology By Daniel Villanueva
  • 2. Thesis Question Archaeologists dont always have the luxury of large sample sizes, especially when looking at pre-historic populations from San Francisco. When comparing small samples to larger ones, when are differences between the samples due to actual differences between the populations, and when are differences due to sampling error?
  • 3. Sources CA-SFr-7 N=28 CA-Ala-342 N=42 CA-Ala-329 N=167, N=365 Various sites (CA-CCo-138, CA-YOL-13, ?, Etc.) N=42
  • 4. Dental Attrition Dental attrition for adult individuals from SFr-7 ranged from stage 2 to stage 4, with dental attrition first becoming evident in young adults (Rudo 1982). In comparison, dental attrition for individuals from Ala-342 range from stage 3 to stage 8, with dental attrition first becoming evident at 3 years of age (Jurmain 1983). There are no individuals from SFr-7 between the ages 3-15 years of age. While no dental carries were present in any individuals from SFr-7, apical abscesses were common (Rudo, 1982).
  • 5. Vertebral Osteophytosis Vertebral osteophytosis (VOP) is the development of degenerative lesions between the fibrocartilagenous joints of the vertebral column (Jurmain, 1990). At SFr-7, VOP affected 30% of the adult population, occurred exclusively in individuals past the age of thirty, and had no apparent correlation with gender or mode of burial. At Ala-342, VOP affected 85.7% of the adult population, manifesting as early as 16-23 years of age.
  • 6. Vertebral Osteophytosis Ala-329 SFr-7 N=92-138 N=? C-M 55.7% 10% C-S 28.9% 10% C-A 4.7% 5% T-M 59.7% 10% T-S 25.3% 5% T-A 2.6% 5% L-M 77.6% 10% L-S 68.4% 20% L-A 3.9% 25% (Jurmain, 1990)
  • 7. 2 individuals from SF-7, a male and a female between the ages of 21-25, displayed possible cranial trauma (Rudo, 1982). Assuming that this assessment is correct, the frequency of cranial trauma among adults at SFr-7 would be 10%. Cranial Trauma 8 out of 365 individuals from Ala-329, displayed some sort of cranial trauma (2.2% of sample). 7 cases came from the 260 adults from the site (2.7% of adults) All instances of cranial trauma were found in males (5.2% of the male sample) (Jurmain, 1997). A 23-30 year old male was the only individual out of 42 from Ala-342 that displayed a depressed cranial fracture (2.3% of sample). Among adults, the frequency of cranial trauma would be 7.1% Among adult males, this frequency would be at 14.3%
  • 8. Cranial Trauma Cranial depressions are not necessarily indicative of interpersonal violence. Out of all three samples, only one skull from Ala-329 reported a cranial trauma with an imbedded obsidian fragment. All reported depression fractures from Ala-342 and Ala-329 showed signs of healing.
  • 9. Post-Cranial Trauma Individuals from the counties of Sacramento, Yolo, Alameda, Contra Costa, and some from unknown origin were pooled together for an analysis of interpersonal violence in the San Francisco bay-area/Central California (Gabet, 1997). Most points fell into two distinct groups based on length and width. Relatively larger points presumably belonged to spears, while the majority of points from this sample were from the smaller cluster that may have been attached to arrows (Gabet, 1997)
  • 11. Post-Cranial Trauma The higher frequency of injuries on the left side of the body may suggest right-handed archery (Gabet, 1997). The higher frequency of injuries along the central axis of the body may suggest that archers were taking precise shots at their targets (Gabet, 1997). 30 of the 42 individuals used for this analysis were adult males. Nearly all males displayed some sort of healing after injury, although this did not necessarily mean that the individual did not eventually die from infection.
  • 12. Conclusions Error: SFr-7 was not entirely excavated, and is only one of ten to twelve midden sites along Visitation Valley and Hunters Point. The complete absence of individuals from ages 3-15, suggest that perhaps some individuals were buried elsewhere, or may have been cremated. Furthermore, the top four feet of the site was destroyed prior to excavation, most likely due to weather. Ala-329 may have been utilized by more than one village group. This may explain the large amount of individuals buried at this site, and may skew the meaning of cranial trauma and VOP frequencies. Ala-342 displayed a number of disassociated bones. Some bones could be reasonably attributed to nearby burial lots. The remainder of bones belonged to a maximum of 13 individuals. Without the sample sizes from each site, it is impossible to determine the frequencies of interpersonal violence on a site-to-site basis. Two individuals from YOL-13 displayed four or more projectile wounds, and nearly 村th of all projectile wounds came from CCo-138.
  • 13. Conclusions Dental Attrition: Individuals from Ala-342 may exhibit more severe dental attrition than those from SFr-7 due to diet. Ala-342 is located further inland, where acorns, hard nuts and seeds would have made up a large portion of the diet. While seeds and tubers would have been part of the diet at SFr-7, faunal analysis suggests that shellfish, deer, sea-otter, fish, and waterfowl would have been a more readily available resource. The practice of chewing lime with tobacco may also have contributed to dental attrition (Knott, 1979).
  • 14. Conclusions Vertebral Osteophytosis: The pattern of VOP at SFr-7 suggest that the primary caused of VOP was aging. While not all old individuals exhibited VOP, Rudo did not specify whether VOP was not scored due to absence of the pathology, or the absence of vertebral elements. This may explain why there is a high frequency of Ankylosis, with low frequencies of moderate to severe VOP.
  • 15. Conclusions Cranial Trauma: Cranial trauma from SFr-7 cannot be definitively correlated to interpersonal violence. Cranial trauma from Ala-342 and Ala-329 may have been due to interpersonal violence, as all instances were in males. However, these injuries may also be a result of accidents while hunting. Only the skull with the imbedded projectile from Ala-329 can confidently be attributed to interpersonal violence.
  • 16. Conclusions Post-Cranial Trauma: No post-cranial trauma attributable to interpersonal violence was found at SFr-7. However, the burial of a female with an associated projectile point suggests she was the victim of interpersonal violence, as no other projectile points were present at SFr-7. This individual also displayed a cranial fracture.
  • 17. Provenience of Archaeological Elements at SFr-7
  • 18. Conclusions More research is necessary to make more accurate conclusions about the people that lived near SFr-7. It is also important to make distinctions not only by location, but by temporality. VOP, instances of interpersonal violence, and dental attrition may be concentrated or absent during specific time periods.