Final Exam Flashcards
Shared Traits of Hominini
-bipedality
-increased brain-to-body size (encephalization)
-anterior foramen magnum
-no honing premolar
-reduced canines
-reduced sexual dimorphism
-intermembral index 70-90
Sahelanthropus tchadensis “Toumai”
-Date and location
-earliest known human ancestor, 7.6-8 mya
-Found in Chad
Sahelanthropus tchadensis “Toumai”
-Traits
-massive brow ridge***
-small brain (320-380 cc)
-less prognathic
-large nuchal crest
-anterior foramen magnum
-habitat: gallery forest along a river surrounded by grassland
Orrorin tugenesis
dates and location(s)
-5.9-5.7 mya (dated by argon-argon)
-found in the Tugen hills in Kenya
Orrorin tugenesis
traits
-thick enamel (implies eating nuts, seeds)
-angle of femoral head indicates bipedality
-arms = arboreal
-legs = terrestrial
The Pliocene climate
5.3-2.6 mya
global cooling after miocene
this cooling and drying is why grasslands and Savanas became more common
Ardipithecus
two species
Ardipithecus kadabba
Ardipithecus ramidus
Ardipithecus kadabba
5.8-5.2 mya
large, ape like canines
Ardipithecus ramidus
dates and location
4.5-4.3 mya
Eastern Africa
Ardipithecus ramidus
Important traits
-has “hand-foot”**
-small brain (300-350 cc)
-anterior foramen magnum
-arboreal arms and hands
-bipedal pelvis and femur
-abducted hallux, unique morphology to bring hallux inwards
-thin enamel (eats c4 plants such as grass and wheat)
-monomorphic canines (pair bonding)
A brief history of “Australopithecine” discoveries
-originally found in 1924– anterior foramen magnum with enbocast revealing human like brain
-originally not believed to be real due to Darwin’s “Piltdown” man scandal (1912)
-proved that it was legit and bipedal, very strong evidence that it is human ancestor
Australopithecine shared features
-small, ape like brain and face structure
-clearly bipedal
-ape arms
-mix of modern ape and human features
Australopithecus africanus
dates and location
3.3-2.1 mya
South Africa
Australopithecus africanus
Important Traits
primitive arms, but more advanced than A. afarensis
larger brain, human like pelvis
-bipedal
Difference between gracile (Australopithecus) and robust (Paranthropus) “Australopithecines
-A. africanus and A. afarensis had much more gracile skulls than Paranthropus
-post-cranially the same but cranially very different
Paranthropus shared features
huge ass teeth and face
Paranthropus aethiopicus
Dates and Location
2.7-2.3 mya (same as homo)
-Kenya/Ethiopia, evolving in response to climate change
Paranthropus aethiopicus
Important traits
HUGE crest
very prognathic
Paranthropus boisei
Dates and Location
2.5-1.4 mya
East Africa– Ethiopia to Malawi
Paranthropus boisei
Important traits
-flexed cranium (face is “flexed” inwards like a dish)
-anterior crest
-500-540 cc (bigger brain
Paranthropus robustus
Dates and Location
1.8-1.0 mya
South Africa
Paranthropus robustus
Important traits
-Least robust out of three
-reduction of teeth size due to warming climate and different foods
-very similar to P. boisei but less robust
Australopith Chronology & Biogeography
homo Paran.
\ /
|
Au.
Au. > early Homo > Paran. > Au. die out > Homo erectus > Paran. die out
Adaptive radiation
rapid diversification in a lineage
- 2.6 mya = start of Pleistocene
-Savanah hypothesis not = bipedality
Modified Savanah Hypothesis
-origin of HYPERmetadontia (big ass teeth)
-expansion of tool use
-big teeth for Paran., big brains for Homo
Reconstructing diet: Dental anatomy and morphology (teeth)
types of teeth, how many, what size, etc
Reconstructing diet: Mastication system (levers)
bones (maxillae and mandible), teeth, joints, neurovascular elements, and the muscles responsible for moving the mandible
Reconstructing Diet: Wear patterns (enamel microwear)
-more scratches= folivore
-more pits=frugivore
-lots of pits= brittle diet
-Limitation: “last supper phenomenon” (short term abrasions from weeks-months b4 death)
Reconstructing Diet: Isotopes (C3 versus C4 vegetation)
-Ratio of stable carbon isotopes 13C/12C
-C4 plants (open habitat grasses) have more 13C than C3 plants (forests)
What are the main differences between Australopithecus and Paranthropus diets?
Megadont vs Hypermegadont
Strong mastication vs Powerful mastication
More scratches (folivore) vs More pits (brittle diet)
30% C4 vs 30% C4, P. boisei = mainly C4
Fallback foods and adaptation
resources of poor nutritional quality that become important when preferred foods are scarce
Earliest evidence of stone tools & cut marks
Stone tools:
-Lomekwi, Kenya
-3.3 mya
-preparing meat and/or cracking nuts
Cut marks:
-Dikika, Ethiopia
-3.4 mya
-flesh removal of animals to access marrow
Climate Change
-MODIFIED Savanna Hypothesis ≠ origin of bipedality
=origin of hypermetadontia =expansion of tool use
Earliest specimen of Homo
-2.8 mya
-Homo habilines
The Habilines (general characteristics)
-610-750 cc
-reduced dentition
-precision grip (large flat tips of fingers)
-small body size
-Generally similar to Australopiths
-Obligate biped
-Still some arboreality -Larger brained
-Tool making
How much variation is there within a single species?
Lots!
12.4 coefficient of variation for cranial capacity for Habilines
How do we access species variation?
Coefficient of Variation:
Measure of dispersion =Standard deviation/Mean
Qualitative characteristics (do they follow a normal mammalian pattern of sexual dimorphism?)
Supra-orbital torus
Supra-orbital sulcus
Temporalis origin
Nuchal origin
Canine size
Prognathism
Homo habilis
Dates
Location(s)
-2.3 – 1.6 mya
-All of eastern African and South Africa
homo habilis
important derived traits
-human like thumb
-human-like wrist bones (SOME)
-phalanges curved
-long arms
-widely dispersed
-robust cranium
-precision grip (tools)
Homo rudolfensis
Dates
Location
-1.9 mya (possibly 2.4)
-Eastern Africa
Homo rudolfensis
important derived traits
-less robust
-slightly bigger body size
-larger teeth and palate
The Erectines
dates & locations?
-2.0 mya - 117 ka
-old world distribution
One or two species?
I think yes
Quantitative
-different cranial robustness
-different measurements of cranium
Homo erectus sensu lato (shared traits)
- Much encephalization
- Long, low cranium
- Full facial prognathism
- External nose!
-intermembral index: 75
-long femur
-human like pelvis
Endurance running hypothesis
he endurance running hypothesis is a series of conjectures which presume humans evolved anatomical and physiological adaptations to run long-distances
used for hunting, avoiding other predators
Persistence hunting hypothesis
our bipedal hominin ancestors evolved to be exceptional distance runners as a result of selection to run prey animals to exhaustion in the heat of the da
Expensive Tissue Hypothesis
the metabolic requirement of relatively large brains is offset by a corresponding reduction of the other tissues, such as gut size.
goes hand-in-hand with endurance running and hunting because we needed more meat to sustain such a large brain
Stone tool (lithic) technologies
lithic technology includes a broad array of techniques used to produce usable tools from various types of stone.
Hypotheses for pan-African and Eurasian dispersal of Homo erectus
Intrinsic
- Relating to essential features of the organism itself
Extrinsic
- Relating to factors external to the organism
Intrinsic hypothesis
Intrinsic
* Large body size X
* Large brain X
* Tooluse X
* Human-like
intermembral index
* Flexible behavior
* Increased meat
consumption
Extrinsic hypothesis
- Escape from disease X
- Normal mammalian
dispersal X - Following predators X
- Following prey X
- Demographic pressure
- Environmental
influence
Homo heidelbergensis
Dates
Location(s)
-600 Ka – 200 Ka
-old world dispersal
Dispersal hypotheses
-Multiregional hypothesis
Multiregional Evolution
-Recent African Origins
Homo neanderthalensis
Dates
Location(s)
-230 ka - 30 ka
- Southern Europe and Asia
Homo neanderthalensis
Important derived traits
-large face
-occipital bun
-HUGE nasal aperture
-swept back cheek bones
-no chin
-retromolar gap
-heavy wear on front teeth
-large body mass
-intermembral index of around 70
Homo neanderthalensis
life history
-matured faster than humans
Homo neanderthalensis
Lithic technologies
Mousterian and Levallois technique
Homo neanderthalensis
Diet
nitrogen isotopes (putrified meat)
Homo neanderthalensis
hunting
distribution of injuries similar to rodeo riders or agricultural workers
Homo neanderthalensis
art and culture
-symbolic art
-burial of the dead
-probably could speak to some degree
The hobbit: Homo floresiensis
Dates
Location(s)
-100-60 Ka
-Liang Bua, Flores Island
The hobbit: Homo floresiensis
important traits
- small brain
-no chin
-slightly prognathic
-scapula positioned more on the side
-humerus with little torsion
-long arms
-flaring iliac blade
-short femur
-Australopith body proportions, except with larger feet
Which hypothesis regarding H. floresiensis is best supported?
- It is pathological (Homo sapiens)
-asymmetry
-probably not because they don’t have any modern syndrome that would cause this - It is an island dwarf form of Homo erectus
-most likely because of island rules (large animals get smaller and small animals get larger) - It evolved from a species before Homo erectus
-no real evidence. what did it evolve from?
The human: Homo sapiens
Dates
Location(s)
- 315(195) Ka – present
- all over!!
The human: Homo sapiens
important traits
Cranial capacity: 1200-1500cm3
Skull short (front to back)
Skull tall (top to bottom)
Rounded cranium
Orthognathic
Short face
Flexed cranium
Vertical forehead
Canine fossa
Chin!
Dispersals- timing of the earliest occurrences in different regions:
Africa
Middle East
Australia
Asia
Europe
The Americas
What is forensics?
The use of scientific methods in solving crimes and in legal settings
Why are statistics so important for forensics?
allows for classifications, even for unknowns
Identification of the four main biological identifiers
Ancestry
Sex
Age
Stature
Idiosyncratic variation
those factors that produce variations in human/system response to the problem situatio
Behavioral indicators
osteopathlogical signs of certain behaviors (diet, abuse, etc)
Pathology & disease
way to identify what happened to an individual during their life
