Week 1: Introduction

Question 1

Palaeoanthropoly

What sources do we have

Answer 1

• the morphology of present day primates
• the behaviour of present day primates
• chemical and physical data
• tools and cultural objects
• contextual information
• fossil hominins
• other fossils
• DNA (ancient and recent)

Question 2

How do we find hominin fossils

Answer 2

• excavation (retrieving fossils and artifacts)
• survey (scouting for fossils on the surface)
• the great rift valley
• volcanoes
• rock-hewn churches of lalibela
• fiels work
• afar triangle today
• “the crawl”
• sieving

Question 3

environment and biochronology

what can fossil fauna tell us?

Answer 3

• bovids and small mammals are in dense forests, woodland, and grassland
• proboscidea and suids evolve fast

Question 4

What are bovids

Answer 4

• bovid family comprise of biological family of cloven-hoofed, ruminant mammals that includes cattle, bison, buffalo, antelopes, sheep and goats

Question 5

what are proboscidea

Answer 5

• a taxonomic order of afrotherian mammals containing one living family and several extinct families
• encompasses the elephants and their close relatives

Question 6

what are suids

Answer 6

• refers to a member of the suidae family
• includes pigs and wild boars

Question 7

dating and time scales of fossils

Answer 7

• geological time scales (what happened when?)
• shows ice ages

Question 8

OIS

Oxygen Isotopic Stages

Answer 8

• the proportion of O16 and O18 in the seawater is proportional to the ice free ocean surface area, as the lighter O16 evaporated preferentially
• by using ice cores from deep drillings in the Arctic/Antarctic you can create curves of proportions of these isotopes where δ18O approximates global temperatures ( δ18O is the difference of O18 concentration from a standard )
• phases are numbered consecutively backward with the Holocene being OIS 1, cold periods have even numbers while warm phases have odd numbers

Question 9

What dating methods are used

Answer 9

• relative dating
• absolute dating
• direct dating
• indirect dating

Question 10

what is relative dating

Answer 10

estimated age relative to other finds or sites

Question 11

what is absolute dating

numerical/chronometric

Answer 11

the exact age in years based on physical/chemical properties, there are numerous assumptions subject to statistical variation and independent of other sites or finds

Question 12

what is direct dating

Answer 12

techniques that directly measure the age of artifacts, fossils, or other objects, rather than relying on the age of surrounding materials

Question 13

what is indirect dating

Answer 13

determining the age of an artifact or feature by relating it to another object or matrix of known age, rather than directly dating the item itself

Question 14

tephrostratigraphy

Answer 14

the study and dating of pyroclastic layers of volcanic ash

Question 15

biostratigraphy

Answer 15

• a branch of stratigraphy that uses fossils to establish the relative ages of rocks and correlate different rock layers
• it is geographically widespread
• rapid morphological changes
• directional evolutionary trends
• first appearance and extinction at the same time everywhere

Question 16

what are important taxa

Answer 16

• rodents
• suids
• elephants
• equids

Question 17

paleomagnetism

Answer 17

the study of earth’s ancient magnetic fields as recorded in rocks and sediments

Question 18

paleomagnetism

geometric polarity time scale

Answer 18

• a chronological framework that records the history of Earth’s magnetic field polarity reversals
• chrons can be normal (today) or reversed
• subchrons are short
• it is especially important for human evolution

Question 19

absolute dating

general features of isotopic dating

Answer 19

• radioactive delay is constant
• they are independent of temperature, moisture, pH
• half life of radioactive material allows age determination

Question 20

radiocarbon dating

carbon-14 dating

Answer 20

• a method for determining the age of organic materials up to about 50,000 years old
• works by measuring amount of carbon-14 remaining in a sample which decays at a known rate
• C14-C12 ratio is variable
• C14 is not likely to enter biosphere
• C14 is not from the atmosphere

Question 21

radiocarbon dating

postdepositional process

Answer 21

natural and anthropogenic activities that occur after sediments or artifacts are laid down, altering their original state and potentially impacting their preservation and interpretation
* erosion
* flooding
* animal activity
* human disterbances

Question 22

radiocarbon dating

contamination

Answer 22

• a significant issue
• even small amounts of extraneous carbon can skew the results, leading to inaccurate age estimates
• can be natural; soild or plant roots
• or artificial; conservation chemicals or modern carbon

Question 23

carbon dating methods

Answer 23

• conventional radiocarbon dating
• AMS dating

Question 24

radiocarbon dating methods

conventional radiocarbon dating

Answer 24

• counting of beta radiation through liquid scintillation detectors
• it is cheap, inaccurate, and needs a large sample size
• up to 30-40 ka

Question 25

# radiocarbon dating methods AMS dating

Answer 25

* direct counting of C14 atoms through accelerator mass spectrometry * expensive, accurate, faster, needs smaller sample size * theoretically up to 100 ka, in practice 40-50 ka

Question 26

potassium-argon and argon-argon dating

Answer 26

* radiometric techniques used to determine the age of rocks and minerals * K-Ar dating reliees on measuring the decay product of potassium-40 to argon-40; can be challenging to obtain accurate ages that have undergone significant heating/contaminated with excess argon * Ar-Ar is a derivative of K-Ar dating that involves irradiating a sample to convert potassium to argon allowing for easier and more procise age calculations

Question 27

# dating examples Ust'-Ishim 1 | a hominin femur

Answer 27

* term given to the 45,000-year-old remains of one of the early modern humans to inhabit western siberia * had intact DNA which permitted complete sequencing of its genome

Question 28

# dating examples Willendorf 2

Answer 28

* an upper palaeolithic site in central europe * numerous cultural horizons interspersed with loeess deposits. abundant charcoal in the cultural horizons/paleosols * earliest known sites in Europe

Question 29

micromorphology

Answer 29

* the study of fine-scale structures and details, particularly in soils, sediments, and other materials * examining thin sections under a microscope to analyze the arrangement and composition of components at a microscopic level

Question 30

# carbon dating examples Galili | a plio-pleistocene site in ethiopia

Answer 30

* about 150m thick succession of fluviatile and lacustrine deposits, interspersed with volcanic horizons * numerous localities with rich fossil assemblages