1. Stable and radiogenic isotopes in Archaeology and Anthropology Henry P. Schwarcz McMaster University Hamilton, Ontario, Canada Christine White and Fred Longstaffe University of Western Ontario London, Ontario, Canada

2. Definitions (loose!) Anthropology: How people live (“culture”) Archaeology: How people Lived (prehistory and later) Paleoanthropology: Who “people” were (evolution)

3. The samples: Bones, teeth Time depth: 3 My to recent

4. Bone is a composite material consisting of: 60 wt% hydroxyapatite: HA Ca 5 (PO 4, CO 3 ) 3 (OH, CO 3 ) OXYGEN + 40% collagen (protein) N, C ATOMS CARBON

5. Diagenesis: when bad things happen to good bones During burial: Collagen degrades: C/N ~ 3.2? Hydroxyapatite “crystallinity” increases  O, C isotopic exchange with soil-water? We can test for these and exclude bad bones

6. Stable isotopes can help inform: Paleodiet: “you are what you eat + x ‰” Paleoclimate: rain, drought, cold, heat Migration: where did people come from?

7. 0 10 20 30 40 50 60 70 years M1 M2, P1, etc M3 teeth bones hair, etc. death Stages of life recorded

8. PALEODIET Nutrient molecules: protein: C, N, H, O Fat: C, H, O Carbohydrate: C, H, O δ 13 C, δ 15 N, δ 18 O of each nutrient varies depending on the source

9. C4 PLANTS δ 15 N (‰) (AIR) δ 13 C (‰) (PDB)

10. IsotopicAnalysis δ 13 C(bone collagen) = δ 13 C (food*) + 5‰ [* mainly dietary protein (?)] δ 13 C (CO 3 -apatite) ≈ δ 13 C (food) + 11 ‰ δ 15 N (collagen) = δ 15 N(diet) + 3 ‰ [“trophic level effect”]

11. You are here Marine consumers: how far would you go for sushi?

12. Walker and DeNiro Am. J. Phys Anth., 1986 Conclusion: Everyone was eating seal meat, but more in the islands Seal

13. MALIBU site Los Angeles

14. Walker & DeNiro Same trend as on Channel Islands: females have higher trophic level Schwarcz & Walker, in prep.

15. Travelling foods: Maize arrives in Ontario ~ AD 700 Maize from Mexico

16. After AD 700 maize replaced wild carbohydrates…

17. Paleoclimate Isotopes as indicators of Temperature: paleotemperatures Mollusk shells in middens Speleothems Teeth, bones Humidity, Rainfall δ 13 C  C3 vs C4 plants (wet vs dry) δ 15 N in collagen: rainfall (aridity) δ 18 O cycles in tooth enamel: seasonality of rain

18. Paleoclimate Isotopes as indicators of Temperature: paleotemperatures Mollusk shells in middens Speleothems Teeth, bones Humidity, Rainfall δ 13 C  C3 vs C4 plants (wet vs dry) δ 15 N in collagen: rainfall (aridity) δ 18 O cycles in tooth enamel: seasonality of rain

19. δ 18 O Paleotemperatures: Sclerochronology Isotopic cycles in marine shell carbonates  Season of occupation of midden-sites Matthieu et al., Paleo 3, 2005 Winter collection

20. Paleoclimate Isotopes as indicators of Temperature: paleotemperatures Mollusk shells in middens Speleothems Teeth, bones Humidity, Rainfall δ 13 C  C3 vs C4 plants (wet vs dry) δ 15 N in collagen: rainfall (aridity) δ 18 O cycles in tooth enamel: seasonality of rain

21. East Africa: calcite in soils Levin et al., EPSL, 2004 C3,moist-------------------C4, hot,dry

22. Migration: O and Sr isotopes Where does he/she come from? Isotopic labels can tell us something About place of origin (but not everything) These are questions in Archaeology/Anthropology Forensic Science (murder victims)

23. δ 18 O(bone) δ 18 O(water) δ 18 O bone tells us δ 18 O of local drinking water

24. δ 18 O of meteoric water varies regionally Decreases with Increasing latitude (poleward) Distance from sea (source of water vapor) Elevation Temperature

27. Strontium isotope ratios 87 Rb  87 Sr t 1/2 = 10 gy.700.705.710.715 87 Sr/ 86 Sr limestones young, low-Rb ------------------  old, high Rb modern seawater

28. White, Price & Longstaffe: Anc. Mesoamerica 2007 seawater.7092

29. Moon Pyramid, Teotihuacan, Mexico In use from AD 1 to 650: Sacrificial victims…from where?

30. Possible sources: δ 18 O and 87 Sr/ 86 Sr White, Price & Longstaffe, 2007

31. Teotihuacan

32. Conclusions Childhood residences of all the sacrificial victims at the Moon Pyramid were foreign to Teotihuacan and could be sourced to regions over Mesoamerica where Teotihuacanos are known to have exerted influence. White, Price & Longstaffe: Anc. Mesoamerica 2007

33. Forensics: The lady from Mammoth Lake

34. Native American or SoutheastAsian? Hair was available for analysis

35. HAIR SAMPLE Maize-rich diet

36. δ 18 O of water (SMOW, ‰) -14 -12 -10 -8 -6 -4 Mammoth native tooth bone

37. DNA evidence: might be from a village in Oaxaca, Mexico

38. δ 18 O of water (SMOW, ‰) -14 -12 -10 -8 -6 -4 Mammoth native tooth Local water --> HA Oaxaca village bone

39. Victim’s bone? This part of her history is still unclear! We need more rain data

40. Conclusions Potential isotopic records: birth  childhood  ??  late adult life Isotopes can be used to trace trajectories of 1.Migration: O, C, N, Sr But not high specificity: 100’s - 1000’s km 2 Need “candidate sites”

41. Isotopes can be used to trace trajectories of 2.Diet: C, N isotopes: movement of hunters/gatherers coast inland spread of cultigens 3. Climate: O, C in soils, animal bone + teeth drought seasonality temperature

42. Acknowledgements Tracy Prowse Phil Walker Martin Knyf Natural Sciences and Engineering Research Council of Canada (NSERC) Social Sciences and Humanities Research Council of Canada (SSHRC)