UNIT 2 Archaeology and Physical Anthropology – Studying the Past

Outline Ethics Methods  Multidisciplinary approach  Bone Biology  Molecular Anthropology  Paleoanthropology Survey and Excavation  Systematic Survey  Excavation Kinds of Archaeology Dating the Past  Relative Dating  Absolute Dating: Radiometric Techniques  Absolute Dating: Dendrochronology

Studying the Past Ethics  You can’t study something because it is interesting or of value to science  Contrasting systems of ethics and values, especially when working outside of your country of origin

Ethics Physical and archaeological anthropologists work in international teams In Paeloanthropology (study of hominid, hominin, and human life through the fossil record), physical and archaeologists work together

Ethics Anthropologists must inform and collaborate with officials in the host country  What materials will be used  Where will artifacts be stored?  Who do different samples belong to? International movement now advocating on behalf on indigenous and formerly colonized people  Some early anthropologists robbed early peoples of history and bodies Lawsuits against museums by groups seeking reparations of remains and artifacts are common  Peru suing Yale to recover objects taken in 1912  Images of native Australian fauna like emu and kangaroo belong to Aboriginal people

Ethics Discussion Who should own and distribute what? How can the truth be known? Should these cultures be allowed to sue for their artifacts back, even when taken so long ago? Why or why not?

STOP – Activity Time Read the article The Kennewick Conundrum in your groups Discuss with your groups (and be ready to discuss as a whole) Who do artifacts belong to? How can you prove it? Where do you draw the line between scientific study and respect for the long dead?

Ethics Bad behavior of past anthropologists can put them against local communities  Anthropologists rely on the goodwill of those communities to study Anthropologists must get informed consent to study  Informed consent: agreement to take part in research after being fully informed about it  Must be told how samples will be collected, used, identified, and potential costs and benefits

Ethics American Anthropological Association (AAA) says anthropologists should not exploit individuals, groups, animals, or cultural or biological materials Recognize debt to people whom they work and give back

STOP! – Review Time What kinds of things must archaeologists consider before studying a place? Why is it important to have a good relationship with the host country? Who does the AAA say anthropologists should not harm?

Methods Physical anthropologists focus on fossil remains and what they tell us about human biology Archaeologists focus on artifacts and what they tell us about past cultures

Multidisciplinary Approach Different types of scientists work with anthropologists  Physicists and chemists help with dating  Work with the different scientific fields to reconstruct ancient biology and ways of life Low tech and high tech tools at sites  Small hand held tools  Photos, maps, drawings, and measurements all entered into notebooks and computers  Aerial photos and satellite photos  Work with geologists and geographers to use images to find footpaths, roads, canals, flooding, deforestation

Bone Biology Bone biology is the study of bones as biological tissue, including its genetics, cell structure, growth, development and decay, and patterns of movement  Osteology is study of skeletal variation and its biological and social causes  Paleopathology is the study of disease and injury in skeletons from archaeological sites Physical anthropologists work in legal context, assisting coroners, medical examiners, and law enforcement agencies  Unknown skeleton found, call anthropologists to help indentify the body  Can tell height, age, and sex of person

Molecular Anthropology Uses genetic analysis to assess evolutionary links Evolutionary distance among living species and dates of most recent common ancestry can be estimated Use genetic clocks to estimate divergence time among species

Paleoanthropology Study early hominids and hominins through fossil remains Teams usually consist of scientists, students, and local workers Paleontologists and geologists are called in early surveying to predict hominin sites

Survey and Excavation Excavate – dig through layers of a site Sites are usually part of larger social systems Systematic survey  Study of settlement patterns over a large area  Reconstruct settlement patterns

Survey and Excavation Through excavation, archaeologists recover remains by digging through layers of deposits that make up a site Layers used to establish relative time order of materials encountered in the dig Excavation is very resource heavy and expensive  Digs not allowed without good reason Sites must be mapped before being excavated

STOP! Review Time What methods did archaeologists use? What is bone biology? What is molecular anthropology? What is the difference between surveying and excavation?

Dating the Past Different methods and ways to date fossils with different degrees of precision Relative dating  Establishing a time frame in relation to other strata or materials Dating methods based on stratigraphy, the science that examines the ways in which earth sediments cumulate in layers called strata

Absolute Dating: Radiometric Techniques Fossils also have absolute dating – establishing dates in numbers or ranges of numbers Several methods  Carbon dating  Radiometric technique  Measure the amount of 14C in organic material to tell fossil’s date of death Half life is short so less dependable for specimens older than 40,000 years

Absolute Dating: Radiometric Techniques Another is Potassium/Argon  Half life of 1.3 billion years  Older the specimen, more reliable the date Uranium series dating  Measures fission tracks produced during the decay of radioactive uranium Thermoluminescence (TL) and electron spin resonance (ESR)  Measure electrons constantly being trapped in rocks and minerals

Absolute Dating: Dendrochronology Dendrochronoly is tree-ring dating  Wide rings during wet years and narrow during dry  Climatic variations produce distinctive year-by-year patterns Crossdating – process of matching ring patterns among trees and assigning rings to specific calendar years Limited to certain tree species  Those growing in climates marked with seasons  Trees must come from same region

Absolute dating techniques TechniquersAbbreviationMaterials DatedEffective Time Range Carbon COrganic materialUp to 40,000 years Potassium-argonK/A and 40KVolcanic rockOlder than 500,000 years Uranium series 238 UMineralsBetween 1,000 and 1,000,000 years Thermoluminescence TLRocks and minerals Between 5,000 and 1,000,000 years Electron spin resonance ESRRocks and minerals Between 1,000 and 1,000,000 years DendrochronologyDendroWood and charcoalUp to 11,000 years

STOP! Review Time What are the two types of dating methods? What are the different types of absolute dating methods?