anth 168 final (lab content)

common characteristics (of the genus homo)

common characteristics (of the genus homo)

• increase brain size and altered morphology

• flatter face (reduced prognathism)

• smaller jaws and teeth

• refinement of bipedalism (longer legs; shorter arms)

• sophisticated tool use

• evidence of culture

homo habilis

• means “handy” or “skilled”

• 2.5-1.7 mya

• first found in Olduvai Gorge, Tanzania

• associated with first stone tools (Oldowan)

• small brain (610 cc) similar to Australopithecines

• slight prognathism

• homo-like dental morphology (small canines, small cheek teeth) with Australopithecine-like postcranial

• no chin

• definitely bipedal

homo erectus

• first found in West Turkana, Kenya

• 1.9 mya - 108 kya

• increase in brain (900 cc) and body size (6ft tall!) from Homo habilis

• smaller teeth

• receding forehead, elongated skull, flat occipital torus, reduced prognathism

• sagittal keel

• no chin

• new tool culture (Acheulean)

• potential use of fire

• first hominin to migrate out of Africa (1.9-1.6 mya)

archaic homo or homo heidelbergensis

• holotype found near Heidelberg, Germany

• drastic climatic changes (610-115 kya)

• possible ancestor to H. neanderthalensis and H. sapiens

• increase in brain size (1250cc)

• occipital torus not as flat as H. erectus

• reduction in cranial and post-cranial robustness, reduced prognathism

• large orbital torus

• no chin

• acheulean tools, fire use, and burials

homo naledi

• rising Star Cave, South Africa

• 335-236 kya

• brain size: 500 cc

• derived hand characteristics indicating precision handling

• small bodied like larger australopithecines

• defined orbital torus

• sagittal keeling, smaller than H. erectus

• mandible more gracile than other Homo

• no chin

• probable tool use

• evidence for use of fire and purposeful burial

homo floresiensis

• surprising find in Flores, Indonesia

• 190 kya - 50 kya

• 3-4 ft tall, cranial capacity of around 400 cc

• large teeth for small size

• no chin

• receding forehead

• hunted small elephants and large rodents

• made and used stone tools

• used fire

homo neandertalensis

• found in Neandertal Valley, Germany

• 250 - 30 kya

• lived at the same time as H. sapiens

• large cranial capacity, larger than modern humans (1650 cc)

• pronounced supraorbital torus

• long and low skull, sloping forehead, rounded occipital bun, large nose

• smaller teeth, larger jaw

• several tool culture types (Mousterian and Levallois), intentional burial, and other cultural practices

modern homo sapiens

• out of Africa vs Multiregional Hypothesis

• 220 kya - present

• cranial capacity 1250 cc

• evidence of mating between groups (we see Neanderthal and Denisovan DNA in human populations today)

• not a lot of information on Denisovans (only a phalange and some teeth

modern homo sapiens characteristics

• rounded cranial shape

• tall, vertical forehead

• reduced supraorbital torus

• smaller teeth

• mental eminence (chin!)

• more gracile post-cranial features

• longer limb proportions

• cultural explosion (paintings, jewelry, musical instruments, throwing spears)

• diversity of tool technologies

infectious processes

pathogenic factors which alter bone by attacking it.

• ie: osteomyelitis, tuberculosis, and leprosy

sequestrum

an infected area of bone that the body isolates

involucrum

a shell of new bone created around the sequestrum, to wall off the area and prevent the free movement of infectious agents

cloaca

pus created in the sequestrum will drain through holes in the involucrum

syphilis

caused by infection of bacterium Treponema pallidum. advanced infection will attack the cranium, leaving distinctive lesions

tuberculosis

if left untreated, Mycobacterium tuberculosis will spread to infect the spine, leaving lesions on the vertebra

periostitis

infection of the periosteum, is characterized by a wooden, grainy texture on bone.

noninfectious processes

though not infectious, these factors remodel bone as a result of an underlying disease.

• ie: cancers or congenital disorders

• malnourishment can cause recognizable damage to the skeleton over time

osteosarcoma

uncontrolled growth of bone tissue. it can occur on any bone and is found in pre-industrial contexts

• most cancers affect osteoblasts to grow large regions of new bone. they are distinguishable from involucra by an increased volume and the formation of a tumor, rather than a thin shell.

cribra orbitalia

caused by iron deficiency (anemia). results in porous, sandy texture on the superior portion of the orbitals. when this process occurs on other cranial bones, it is called porotic hyperostosis

rickets

a lack of vitamin D will cause long bones to bow (curve)

scoliosis

an exaggerated lateral curvature of the spine caused by various conditions, some idiopathic (unknown)

osteoarthritis

inflammation of a joint. caused by bones rubbing against each other due to a lack of a cartilage buffer. advanced rubbing of joints together can result in the polishing of the ends of the bones (which is called eburnation)

mechanical processes

factors which directly remodel bone as a result of cultural practices, accidental damage, or violence

modification

certain cultural practices modify the shape of bone. usually beginning early in life, though some are the result of medical procedures.

trauma

direct damage to bone. can be blunt or sharp force trauma.

cultural modification

many cultures around the world perform some kind of body modification, the most extreme examples leave conspicuous signs on bone. the most common are modifications to the skull.

• ie: changing skull shape by binding the skull or use of a cradleboard

• trepanation involves cutting off pieces of the skull, and will leave (usually square shaped) holes that show signs of healing (given the procedure isn’t immediately fatal)

post-mortem cultural modification

some cultures also modify skeletal material after death). other times skeletons are disarticulated and re-constructed to form decorations

dental pathologies and modifications

• carries: cavities

• wear: repeated contact causes teeth to wear down.

• staining: enamel can change color over time from prolonged exposure to a staining agent (ie: tobacco or coffee)

• filling: reshaping teeth into points, or creating horizontal scores.

• anomalous growth: sometimes teeth will

  either fail to erupt or grow misshapen or in the wrong direction (ie: pegged teeth)

forensic anthropology

biological anthropology concepts applied to medico-legal situations.

• missing persons and homicide investigations, trauma analysis, and human rights investigations

initial questions for a forensic anthropologist

1. is it bone?

2. is it human bone?

3. is it modern human bone?

identification

• biological profile: age, sex, stature, ancestry

• pathology, trauma, & taphonomy

• individualizing characteristics

methods of sex estimation

• pelvic girdle (Os coxae)

• skull

• metrics

sex estimation: os coxae

three main features to look at:

1. ventral arc

2. subpubic concavity

3. ishiopubic ramus

• scoring is from 1-5 for all 3 traits, 1 being closer to female and 5 being closer to male

sex estimation: the skull

• metric methods: measurements between different cranial landmark

• non-metric methods use: glabella, mastoid process, nuchal crest, superior margin of eye orbit, mental eminence

• female = score of 1 or 2; indeterminate = score of 3; male = score of 4 or 5

age estimation methods

• dental formation and eruption

• bone growth and fusion rates

• sutural closure (not used as much)

• pubic symphysis

• rib ends

• heavy multivariate statistical analyses

age estimation: clavicles

fusion rate of the medial epiphysis of the clavicle using the Shirley & Jantz (2010) method:

• score 1 = unfused (no fusion of epiphysis and diaphysis)

• score 2 = fusing (look for an epiphysis cap with an obvious epiphyseal scar)

• score 3 = fused (complete epiphyseal union, look for a smooth surface)

ancestry estimation

controversial topic in the field, reinforces the idea that race is biological (which is NOT true)

stature (height)

the bones used (in conjunction or alone) to estimate stature are the femur, tibia, humerus, radius, and ulna

• lower limbs provide most accuracy as they contribute to our height more than the others

• measurements are plugged into regression equations to estimate stature

individualizing characteristics

• can tattoos, surgical implants with serial numbers, scars, dental work

• useful when narrowing down a list of missing persons

sharp force trauma

caused by a tool that is edged, pointed, or beveled

• ie: marks made by a knife, saw, or machete

blunt force trauma

a relatively low-velocity impact over a relatively large surface area

• can result in depressions, fractures, or deformations on bone

• can be caused by impacts from clubs, sticks, fists, etc.

• also commonly a result of car accidents or falls

projectile trauma

high-velocity trauma affecting a small surface area

• usually caused by bullets or shrapnel

thermal trauma

bone alteration caused by exposure to extreme heat

• can be the result of house fires, intentional disposal of remains, plane crashes, etc.

taphonomic changes

processes that alter bone after death

• decomposition

• animal scavenging

• soil and plant staining

• root etching

• weathering:

  • sunlight bleaching

  • water erosion

investigations of mass human rights violations

• assist with identification

• determine number of victims

• trauma analysis

• expert witness