What is a fossil?
Fossils are physical evidence for life that no longer exists. They, therefore, are very strong evidence for evolution, which hypothesizes that there must have been organisms, similar to, but different from, the inhabitants of Earth today.
What is taphonomy?
an entire science that devotes itself to the study of what happens to an organisms' remains after death
-ex. A hominid who has died on a lakeshore begins to decay as bacteria and fungi consume the soft tissues and organs of the individual. If the circumst
What kinds of conditions give the best chance for fossilization to occur?
-happens at the molecular level, replacing the calcium and phosphorous in bones and teeth with the minerals found in the surrounding rock, like iron and silica. Importantly, this is not an all-or-nothing process and thus there are many fossils that still
What kinds of rock are fossils found in and why?
-Fossils generally form in sedimentary rock in which tiny bits of rock, sand, and soil are carried either by wind or water and bury the bones of dead animals
Why is the fossil record biased against forest dwelling animals?
forest sediments often have quite acidic soil, which is not good for bone and tooth preservation. We therefore have a fossil record that is biased against forest-dwelling animals�an unfortunate thing for us since primates tend to live in forest
Steno's Law of Superposition
-Danish scholar living in the 1600s named Nicolaus Steno (or Niels Stensen).
-Steno studied geological formations around Italy and collected the fossils contained in these stratigraphic layers. He deduced that the higher rocks were younger than the lower
Relative dating techniques: Fluorine dating and Cultural dating
-Bones that have been buried for a long time absorb more fluorine than bones that are more recently buried.
- This use of fluorine concentration in bones is one of the first uses of chemical dating, and was used by Croatian paleontologist Dragutin Gorjano
Relative versus absolute dating techniques�how they differ
Relative is a guesstimate
absolute is specific
- what we are really interested in is not relative dating, but absolute dating. Scientists do not just say that dinosaurs lived before humans did, they say that dinosaurs lived up to 65 million years ago, and
Dendrochronology
In the 1920s, an astronomer by the name of A. E. Douglass discovered that the seasons caused trees to suspend their growth in the winter and resume it in the spring. This resulted in an annual formation of a discernible tree-ring and a pattern of tree-rin
Radiocarbon C14 dating
-Carbon usually has an atomic mass of 12 (six protons and six neutrons). But, occasionally, carbon has two extra neutrons and exists as carbon-14. Carbon-14 is radioactive and decays into nitrogen-14 (which has seven protons and seven neutrons). The key t
Radiocarbon C14 dating: Half-life
The key to using this as a dating device is that the decay of carbon-14 to nitrogen-14 happens at a constant and predictable rate. In fact, half of the radioactive carbon in a substance will decay into nitrogen in 5,730 years. All living things take in ca
Radiocarbon C14 dating: What kind of material does it work on?
-All living things take in carbon, including a small (but knowable) amount of carbon-14
Radiocarbon C14 dating: how far back can it date things
-carbon dating cannot be used reliably for anything older than about 50,000 years since all the carbon-14 will be gone
Radiocarbon C14 dating: What element is being used?
-carbon-14 and nitrogen-14
-Carbon usually has an atomic mass of 12 (six protons and six neutrons). But, occasionally, carbon has two extra neutrons and exists as carbon-14. Carbon-14 is radioactive and decays into nitrogen-14 (which has seven protons and
Radiocarbon C14 dating: limits of radiocarbon dating
cannot be used on things that have never lived, or more than 50,000 years old. assumes same amount of carbon 14 present today same amount present in the past
Argon dating: the "clock in a rock"- half life
-argon and potassium have a half-life of 1.3 billion years
-Volcanic rock contains the radioactive isotope potassium-40, which decays into the stable gas, argon. When a volcano erupts, it lays down a bed of ash that contains potassium-40, but the heat of
Argon dating: the "clock in a rock"- why is it useful for dating hominids?
Potassium Argon dating is effective for sites over 100,000 years in age and has been widely used in dating Pliocene and Pliestocene events. It is widely used in paleolithic archaeology and paleoanthropology and has been most widely used for dating early h
Argon dating: the "clock in a rock"-what are its limitations for dating hominids?
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Argon dating: the "clock in a rock"-What is the time period to which it can date?
...The time period is 50,000+ years. I assume the limitations are it can only date hominids which are surrounded by the volcanic layers contain argon gas.
what are its limitations for dating hominids?
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What makes a hominid?
Members of the family Hominidae that occurred after the split from African great apes
What is a protohominid and how are these different?
-Earliest members of the hominid lineage-barely represented in the fossil record, ancestors of hominids
-structure and behavior reconstructed hypothetically
Locomotion first" vs. "brains first" theories of human evolution
-(this is the right one) Locomotion first: ape->bipedal age->intelligent bipedal age (large brain)-> human
-Brains first: ape->intelligent ape->bipedal intelligent ape->human
What was Darwin's theory about the split between hominid and ape?
Darwin speculated that upright walking freed the hands to make and use tools, which led to increased cleverness. His ideas were impressive in light of the fact that they came without the rich fossil record that is known today, or the knowledge of the gene
The Piltdown hoax�what effect did it have on the development of paleoanthropology? - Bipedalism
Charles Dawnson pretended to find remains of creature with ape like jaw and teeth but with a big brain, later found to be fake and from different animals.
-set paleoanthropology back 40+ years bc no one wanted to believe scientists
Bipedalism: Posture
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Bipedalism: "habitual"/obligate bipedalism
hominids do this. we constantly are walking on two legs
Bipedalism: How is bipedalism in hominids distinct from that of birds and kangaroos?
Hominids use one foot at a time, while birds and kangaroos hop on both feet for each step they take
Bipedalism: The bipedal macaque
Israeli zoo, Safari Park
Natasha, a 5 year old macaque almost died of severe stomach flu and after surgery started walking bipedally
Skeletal indicators of bipedalism: foramen magnum position�centered (anterior) vs. toward the back (posterior)
-Positioned further forward (anteriorly) under skull in the middle (this arrangement is exclusive to us)
-Apes have it in the back
-latin for big hole, how spinal column connects to brain
Skeletal indicators of bipedalism: S-shaped spine
2 types of hominid spine
-Great apes have a straight back
-humans have an S
Skeletal indicators of bipedalism: basin shaped pelvis, (also know impacts on birthing with bipedal pelvis shape)
-Bipedalism creatures have short, broad, and basin or "bowel" shaped pelvis our intestines sit in
- out joints are bigger, asatabula twice as apes
-our joints are also more robust, heavy duty
-gorillas have massive abs, keeps gut in
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Skeletal indicators of bipedalism: lower limb features: enlarged femoral head, knee angled inward, short toes
-enlarged head of femur
-knee angled inward (valgus=we don't move side to side when we walk, so we don't waste calories)
-short toes
-long hindlimbs
Skeletal indicators of bipedalism: arched feet
-Big toe (hallux) enlarged and nonopposable(??)
- longitudinal arch forms to better support weight
Skeletal indicators of bipedalism: Valgus angle
knee angled inward (valgus=we don't move side to side when we walk, so we don't waste calories)
Hypotheses of the origin of bipedalism: freeing hands, running after game, looking over tall grass, keeping cool, ability to make tools, and sexual display. Know which one's Prof. agrees with.
prof agrees with freeing hands
Lecture notes on why certain morphological adaptations took place, what use they are to bipedal locomotion
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What characterizes a hominid, when did certain adaptations take place (i.e. bigger brains, dental structure, opposable/non-opposable hallux, honing/non-honing mastication)?
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Protohominids: Sahelanthropus tchadensis
oldest possible hominid species
-hominid live?: Chad, central/northern Africa
-What kind of environment did it prefer?:
-When was the hominid alive?: 7-6 mya
-Which, if any, famous site is associated with the fossil finds? (i.e. Lactoli, Bouri, etc. )
-is
Protohominids: Orrorin tuganensis
-where in Africa did the hominid live?: Tugen hills, kenya
-What kind of environment did it prefer?
-When was the hominid alive?: 6mya
-Which, if any, famous site is associated with the fossil finds? (i.e. Lactoli, Bouri, etc. )
-is the hominid represente
Earliest consensus hominid - Ardipithecus kadabba
-where in Africa did the hominid live?: Ethiopia, west side of fertile
-What kind of environment did it prefer?
-When was the hominid alive?: 5.8-5.5 mya
-Which, if any, famous site is associated with the fossil finds? (i.e. Lactoli, Bouri, etc. ) Rift Va
Earliest consensus hominid - Ardipithecus ramidus
-where in Africa did the hominid live?: Middle Awash (ethiopia)
-What kind of environment did it prefer? woodland
-When was the hominid alive? 4.4 myo
-Which, if any, famous site is associated with the fossil finds? (i.e. Lactoli, Bouri, etc. )
-is the ho
East African australopithecines: Australopithecus anamensis 4.2-3.9 mya
-Kenya and Ethiopia lake draram?
-What kind of environment did it prefer?
-When was the hominid alive?
-Which, if any, famous site is associated with the fossil finds? (i.e. Lactoli, Bouri, etc. )lake draram?
-is the hominid represented by a famous specim
East African australopithecines: Australopithecus (Kenyanthropus) platyops
flat face man of kenya,
where in Africa did the hominid live?
-wodland habitat
-3.5 mya
-Which, if any, famous site is associated with the fossil finds? (i.e. Lactoli, Bouri, etc. ) Lake turkana
-is the hominid represented by a famous specimen (e.g. Lucy)
East African australopithecines: Australopithecus afarensis (Lucy, The Laetoli footprints)
-where in Africa did the hominid live?
-What kind of environment did it prefer?
-When was the hominid alive?
-Which, if any, famous site is associated with the fossil finds? (i.e. Lactoli, Bouri, etc. )
-is the hominid represented by a famous specimen (e.
East African australopithecines: Australopithecus garhi- what does garhi mean? What was found alongside this specific hominid?
garhi means surprise
-where in Africa did the hominid live?
-What kind of environment did it prefer?
-When was the hominid alive?
-Which, if any, famous site is associated with the fossil finds? (i.e. Lactoli, Bouri, etc. )
-is the hominid represented by
When did the great apes and hominids split?
7-10 mya
miocene period
What are the major differences between robust and gracile australopithecines, what does this say about diet?
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The Earth is about ______ years old.
4.6 billion
In terms of geologic time, when did humans appear on Earth?
Very recently
In what kind of rock are fossils usually found?
sedimentary
which of the following is NOT an absolute dating method?
stratigraphy
Which US President reported the discovery of a fossilized ground sloth in Virginia to the American Philosophical Society?
Thomas Jefferson
The English surveyor who developed the technique of stratigraphic correlation between regions was
William Smith
Charles Lyell is considered the father of vertebrate paleontology.
False
Radiocarbon dating relies oin an element that has a half-life of 5,730 years. Therefore, it is a useful technique to date materials that are millions of years old.
False
Which of the following body parts has the best chance of fossilizing?
teeth
Dendrochronology relies on a record of tree rings.
true
Using direct radiometric dating of ____ provides very accurate dating for many East African Rift Valley hominid sites.
volcanic rocks
The first hominids appeared in Africa about _______.
7-6 MYA
Where have fossil remains of genus Australopithecus been found?
Africa only
The ________ tradition includes the oldest recognizable cultural artifacts--simple stone tools dating to about 2.6 million years ago.
Oldowan
In addressing the origin of bipedalism, Charles Darwin focused on the impact of ________.
hunting
Sahelanthropus is the oldest known potential hominid genus.
true
At which site would you be most likely to recover fossil remains of Australopithecus africanus?
Sterkfontein, South Africa
About when did the Australopithecine lineage go extinct?
1 mya
Among the living apes, which is humanity's closest relative?
chimpanzees
Evidence that genus Orrorin was bipedal comes mainly from which part of the skeleton?
Femur
brains got bigger
2-2.5 mya
tim white= father of ardipithecus
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