exam 3 Flashcards
paleontology
study of extinct organisms, based on their fossilized remains
paleoanthropology
study of fossil record of ancestral humans and their primate kin
what is a fossil
preserved remnant of a once-living thing
what can fossils tell us?
-species
-age
-activities
taphonomy
the study of what happens to the remains of an animal from the time of death to the time of discovery
context
-where is the fossil found
-why is it important
provenience
location from where the fossil came from
what percent of once living organisms become fossils
0.01%
Why is fossilization so rare?
their formation and discovery depend on chains of ecological and geological events that occur over deep time.
What does this mean for reconstruction of the past?
we are able to get a picture of what things looked like and the past and what coexisted
best conditions for fossilization to occur
its body must be protected from decomposition
What are the 2 basic categories of dating techniques?
-relative dating
-chronometric dating
relative dating
stratigraphy
chemical methods: looking at half life and how much chemical is in the object (carbon)
chronometric dating
tree rings
radioactive decay (potassium-argon)
Which dating method is revealed the Piltdown hoax?
chemical dating
geological principles (4)
stratigraphy
original horizontality
superposition
cross-cutting relationships
stratigraphy
original horizontality
superposition
cross-cutting relationships
What are some techniques for reconstructing past environments?
-climate change
-adaptations in environments
When did the mammal radiation begin?
190 mya
why did mammal radiation begin
extinction of dinosaurs
When do hominins first appear in the fossil record?
23-5 mya (miocene)
what is a hominin
-humans
-human ancestors
What are the 4 key distinguishing features separating humans from the apes?
-locomotion (bipedalism)
-dentition
-brain size
-language
When do these differences appear in the fossil record?
skeleton structure and size
skull of quadrupedal
foramen magnum positioned in the back
skull of bipedalism
foramen magnum is in the middle near the eyes
vertebral column of bipedalism
-curvature inward in lower back
-larger vertebrae
vertebral column of quadrupedal
-shorter
-rainbow shape
pelvis of bipedalism
-wider and shorter
pelvis of quadrupedal
tall and narrow
femur of bipedal
angled femur to bring knees and feet under body
feet of bipedal
non-divergent big toe
arches
stride of bipedal
heel to toe
arms of bipedal
-shorter arms and fingers
-less curvature
hypothesis for the origin of bipedalism in hominins
environmental changes:
-distribution of food
-thermoregulation
Why are the earliest hominins hard to identify in the fossil record
The first members of the human lineage lack many features that distinguish us from other primates.
what is mosaic evolution
that evolutionary change takes place in some body parts or systems without simultaneous changes in other parts
what is diastema
a space separating teeth of different functions, especially that between the biting teeth (incisors and canines) and grinding teeth (premolars and molars) in rodents and ungulates
who is lucy
a collection of several hundred pieces of fossilized bone representing 40 percent of a female of the hominin species Australopithecus afarensis
what did Laetoli find
the earliest hominin footprints in the world (3.66 million years old), discovered in 1978 at Site G and attributed to Australopithecus afarensis
what is Selam
the fossilized skull and other skeletal remains of a three-year-old Australopithecus afarensis female hominin, whose bones were first found in Dikika, Ethiopia in 2000 and recovered over the following years
what did raymond dart find
first austra afri fossil (taung child)
piltdown
paleoanthropological fraud in which bone fragments were presented as the fossilised remains of a previously unknown early human.
what is Malapa
fossil-bearing cave located about 15 kilometres northeast of the well known South African hominid-bearing sites
how do cranial features differ in Paranthropus and Australopithecus
p: increased size of chewing muscles and attachment on the skull
oldowan
-tool
-cores
-flakes
how do dental features differ in Paranthropus and Australopithecus
P: increased size of posterior teeth, reduction of front teeth
How does climate change play a role in distribution of H. erectus?
follows the food supply (migrating animals)
How does technology change play a role in distribution of H. erectus?
oldowan tools brought change in foraging strategies
How does anatomical change play a role in distribution of H. erectus?
larger brains and bodies with modern proportions
What is the tool industry first associated with H. habilis?
oldowan tool
What were the oldowan tools used for?
processing meat, bone, wood, plants, pocket knife
What are the 3 key components of the tool industry?
-flake
-core
-hammer stones
what is flake
stone fragment struck from a core
what is core
raw material source that flakes are removed from
what is hammer stone
used to strike cores to produce flakes or expose bone marrow
What tool industry is seen for the first time with
H. erectus?
Acheulan
acheulan tool
-biface (hand axe and clevers)
-specifically designed
-unchanged for 1 million years
how does oldowan and acheulan differ
old- simple and easily mistaken for something naturally made
What is the Movius line?
theoretical line marking presence/absense of acheulan hand axes
What have researchers been able to determine about hominin activity based
on taphonomic studies?
-hunting and scavenging activity
more scavenging than hunting
How can researchers determine whether hominins were hunters or
scavengers?
tools are better used for cutting bone and meat rather than for killing
What does this research tell us about hominin behavior?
confrontational
passive
sagittal crest
