Human Skeletal Remains Flashcards
What is the biocultural approach?
- Skeletal evidence is the result of interaction between the individual and their socio-cultural environment
- An integration between biological anthropology and social/cultural anthropology
Anders Retzius (1976-1860)
- Swedish anatomist and craniologist
- Argued the skull shape reflected the development of the brain
- “as one can assume…each race or tribe has their own physiological characteristic…expressed in the development of the brain” (1847)
6 principle classes of nutrients
- Modern humans need to obtain up to 50 different nutrients from their diet
- 6 classes: carbs, fat, protein (the 3 macronutrients), minerals, vitamins, water
In what conditions are stomach contents present in graves? give an example
- Only identifiable as stomach contents rather than grave offerings if soft tissues are preserved
- Therefore, best in bog bodies and mummies
- E.g. Tollund Man: limp seed, barley, hemp nettle (criminal? prisoner?)
Analyitcal techniques for stomach contents
- Macroscopic or microscoopic examination
- DNA sequencing: less identifiable the further down the digestive tract
- Can indicate short term diet: 2-3 days before death
- May not be a typical meal, may be related to individual’s closenes to death
Link between pathologies and specific nutritional factors
- Consequences of nutritional deficits mimic effects of infection
- Under-nutrition increases susceptibility to infection
Conditions linked to specific nutritional defects, 3 examples
- Scurvy caused by vitamin C deficit
- Manifested in abnormal bone porosity associated with new bone growth
- Rickets caused by vitamin D deficit
- Manifests in thin, porous bone with large marrow cavities & bowing of long bones
- Iron deficieny anaemia
- Manifests in the skull
When did scurvy and rickets become freuqent?
- Neither are frequent prior to Medieval period
- Pale as sign of status, children working indoors in factories: both socio-economic groups effected
Nutrition and stature, example of Lower Illinois Valley, USA
- Woodland to Messapian transition
- Comparison of femoral length in hunter-gatherers, early agriculturalists, and intensive agriculturalists
- Femur length shortest amon early agriculturalists
- Move to agriculture was damaging for their health
Otzi’s teeth
- Worn to the crown at 45 years old
- In many past groups consuming traditional foods, rapid dental attrition is evident
- Grainy, gritty bread
- Cereals processed in stone querns, contained grit
Anaemia: Heme and non-heme iron
- Iron is an essential mineral involved in oxygen transportation in the blood
- Heme iron is most easily incorporated into the blood and is available from animal sources
- Absorption of heme iron is inhibited by consumptiom of plant proteins and phytates
- Non-heme iron is available from plants but not as well absorbed
- Most commonplace after transition to farming
Cereal based diets, examples of lesions
- Cribra Orbitalia: body lesions on the orbital roof
- Porotic hypertosis: spongy and porous bone
- Lesions of this type are relatively rare prior to agriculture
Diet and Dentition, aging
- Comparing skeletal age with dental age in children can indicate nutritional inadequacies
- Development of teeth under more genetic control than the skeleton: during times of stress, the body focuses on keeping the teeth growing rather than the skeleton
- Age of an individual can be told by teeth better than their skeleton
Diet and Dentition: Hypoplasia
- Defects in enamel of teeth
- Cessation of enamel production resulting in circumferential lines
- Developmental age of dentition well understood
- Timing of hypoplasia can be accurately determined
- Most frequent between 2-4 years in agricultural populations
- Weaning strress, going from breastmilk to less nutritional foods
- Can result from infection
Diet and dental caries: HG vs AG
- Occurence of caries normally associated with high carbohydrate rich diet, e.g. agriculture
- Hunter Gatherers: Average caries is 1.7% of teeth
- Agriculturalists: 8.6% of teeth
- Honey, sugary substances, sweet acorns
Diet and dental calculus info
- Occurence of dental calculus normally associated with diets high in protein
- Inclusions in calculus indicate dietary components
- Macroscopic analysis of plant remains, DNA/protein analysis
Example: Neanderthal calculus on teeth
- Neanderthals in Spain ate mushroom and rhino
- Starch grains and phytoliths indicate consumption of yarrow and chamomile for medicinal purposes
- Self-medicating
Reconstructing diet: stable isotopes
- Carbon and nitrogen stable isotope values are commonly used to reconstruct diet in archaeological populations
- Provides direct evidence for individual dietary intake
- Different types of foods have different carbon and nitrogen isotope ratios
- Chemical signatures of the foods we eat are passed through our bones
- Contemporary research is highly accurate
Bone collagen and bone apatite
- Organic component (collagen)
- Largely synthesised from dietary protein
- Less affected by diagenesis
- Diagenetic alteration is easily detected
- Mineral component (apatite)
- Whole diet (Carbs, lipids, proteins)
- Susceptible to diagenesis
Carbon stable isotope ratios
(look at pwp slide for better detail)
- Carbon isotope ratios: 13C: 12C, mole13C
- Can distinguish between diets based on C3 and C4 food sources
- C3 and C4 plants have different photosynthesis pathways
- C4 plants incorporate more of the heavier isotope 13C than C3 plants during photosynthesis
- C4 plants thus have heavier C-isotope ratios
Adaptation of Maize agriculture
- Transition from hunter-gathering to maize agriculture in the Americas
- Maize = C4 plant
- Hunted/gathered resources = C3 plants + consumers
Marine Carbon Isotope ratios
- 13C values can also be used to distinguish between diets based on C3 plants and marine resources
- C3 plants obtain carbon from atmospheric CO2
- Marine plants obtain carbon from dissolved carbonate
- Dissolved carbonate contains more of the heavier 13C isotope than atmospheric CO2
- Marine resources therefore have heavier 13C than C3 plants
Carbon isotope ratios as dietary indicators
- Transition to farming in Europe
- Debatable archaeological remains linked to the initial introduction of farming are scarce
- Dated indirectly from dietary changes
- Many Mesolithic groups subsisted heavilt on marine resoruces
- Neolithic transition: shift to dependence of terrestrial resources in many areas
Nitrogen stable isotope ratios
- Problem: Carbon isotope ratios of C4 food web and marine resources overlap
- Co-analysis of 13C and 15N can distinguish between terrestrial and aquatic food webs
- 15N isotope values increase with each step of the food change ~3.0-4.0% per trophic level
- Preferential excretion of 14N
- Carnivores will have significantly heaver 15N values than herbivores and plants
Aquatic food webs
- Aquatic food webs are more complex than terrestrial food webs
- Humans subsiting on acquatic resources generally have heavier 15N isotopes than those consuming only terrestrial resources
- Typical 15N of an individual who consumes a diet of mainly fish or sea mammals is 15-20%
Investigating short term vs long term diet vs childhood diet
- Hair and nails = short term diet
- Long bones = long term average diet over 10+ years
- Teeth = childhood diet dentine (weaning, dietary transition in layers of dentine)
Bone cells + their link to disease
- Human bone consists of bone cells
- Osteoblasts: build up bone tissue
- Osteoclasts: break down bone tissue
- In skeletal disease, there is an imbalance between osteoblasts and osteoclasts (too much bone destruction)
- Evidence of disease is hence identified from abnormal bone formation or bone destruction
Osteoarthiritis + progression
- Most common joint disease
- Presence of eburnation or a combination of joint surfaces pitting, body contour change, osteophytes
Progression
- Swelling of joint
- Thinning of cartilage
- Thinning of joint space
- Cartilage destruction
- Bone rubbing against bone
- Possibly fusion of joint
3 types of infectious diseases
- Endemic: spread of disease contained within a particular group, rate of infection is constant
- Epidemic = spread of a disease beyon a single group, rate of infection is increasing
- Pandemic = affects a whole country or the entire world
Osseous (bone) changes linked to infectious diseases
- Osteoblastic activity = new bone formation
- Osteoclastic activity = bone destruction / lytic lesion
- Palaeopathological diagnosis = based on distribution and type of lesions
Pulmonary TB:
- More common
- Droplet infection, cows or human
- Single sneeze = 40,000 droplets
- May result in/from extrapulmonary infections, spread through bloodstream
Tuberculosis
- Facts: cause, early evidence
- Caused by Mycobacterium tuberculosis and Mycrobacterium bovis
- Known as consumption, scrofula, the white plague
- Earliest evidence is in the Neolithic
- Gastrointestinal TB
- Spread of bovine form to humans
- Consumption of infected meat and milk, intestinal pathway
- More common in children
Primary TB
- Spread
- Spread through venous and lymphatic systems
- Forms calcified lesions which contain bacteria, no skeletal involvement
- Person with active TB may infect 10-15 other people per year
Secondary TB
- Immune response
- Reinfection or reactivation
- Fepressed immune system
- Skeleton affected in 3-5% of cases (spine, hips knees)
- Aggressive immune response can destroy normal tissue
TB skeletal changes
- Location of leisions: mainly vertebral bodies and on joints
- Lesions mainly destructive
- Frequent collapse of vertebral bodies: Pott’s disease
- Frequency in skeletal remains in Britian’s Iron Age onwards
3 examples of past infectious diseases and mass mortality events
- Antonine Plague: AD 165, Roman Empire: estimated to have killed 5 billion ppl
- Viral infection, possibly smallpox or measles, cripples body’s immune system
- Bubonic plague/black death: 1347-51, estimated to have killed 30-60% of Europe’s population
- Bacterial infection, destroys body’s immune system
- Cholera: 1830s, 1840/50s, 1880s, killed million of ppl during C19th
- Bacterial infection, dehydrates the body
Extra facts about manifestation on skeleton
- Manifestation of disease on the skeleton doesnt necessarily reflect the experience of the disease (how pain is experienced/percieved is highly variable)
- Most infectious diseases leave no trace on the skeleton
- For a disease to be recognised on bones it has to be chronic
Agricultre and disease
- People got more sick as agriculture began
- Less nutrition, close quarters
Scurvy
- Vitamin C deficiency manifested in abnormal bone porosity associated with new bone growth
- Not present prior to Medieval period
- Leads to reduction of osteoid formation, the weakening of connective tissues, the weaking and thinning of blood vessels
- Juveniles get new bone formation in the joints, adults get it in their orbits and end of long bones
Rickets
- Vitamin D deficiency
- Came to prevalence during times of children working indoors in factories
- Being pale as sign of status
- Rickets manifests in the bowing of long bones and thin porous bones iwth large marrow cavaties