Bio Anthro midterm 2 pt 2
What are stable isotopes?
Forms of oxygen and carbon in different proportions depending on environmental conditions.
What is the extimated age of the earliest hominins?
What is the difference between the old view and the new view on the number of species?
The Old View
: Human evolution with relatively few species and fairly linear
The New View
: Human evolution extremely complicated & species-rich
What are the three Pre-Australopithecines?
Sahelanthropus tchadensis: how old are they and what are their defining characteristics?
Dated - 7 mya
Small Brain (<400 cm3)
Massive browridges & cranial crests
Small face & Anterior dentition
Forward (inferior) foramen magnum (suggestive of bipedalism)
Orrorin tugenensis (“Millennium Man”): how old are they and what are their defining characteristics?
Dated - 6 mya
Very little cranial material but femurand other post-cranial fossils indicativeof habitual biped
Ardipithecus ramidus: how old are they and what are their defining characteristics?
Dated - 4.4 mya
: Woodland environment
40% Skeleton + pieces of 36 individuals
Small brain (300-350 cm3) with relativelyunspecialized teeth and small canines
Unique foot—bipedal adaptations & graspingbig toe
Partially terrestrial, omnivorous/frugivorous
Forward (inferior) foramen magnum
Arm not weight-bearing
Pelvis and leg bones
But lower pelvis with climbing adaptations
Australopithecus afarensis: how old are they?
Dated - 3.8-3 mya
What are the post-cranial features of Australopithecus afarensis?
Relatively long arms
Retention of arboreal adaptations (curved phalanges)
What are the cranial features of Australopithecus afarensis?
Small brain (350-500 cm3)
U-shaped dental arcade
Canine reduced but still large (with semi-sectorial lower 1st premolar)
Where were gracile and robust Australopithecines located?
: South Africa
: South and East Africa
Australopithecus africanus: how old are they and what are their defining characteristics?
Dated - 2-3 mya
Small brain (450-500 cm3)
Less prognathic face
What are the three types of Robust Australopithecines, and where were they located?
A. robustus (South Africa)
A. boisei (East Africa)
A. aethiopicus (East Africa)
Robust Australopithecines: how old are they and what are their defining characteristics?
Dated - 2.5-1 mya
Small Brain (~500 cm3)
Face, Jaws, & Teeth
What are the robust dietary adaptations?
Large Jaw & Molars (Megadont)
What we know about australopithecines?
Small-bodied (3 ½ - 4 ½ ft. tall)
Retention of arboreal adaptations
Pronounced sexual dimorphism
Primarily vegetarian (Hunted nothunter)
Limited tools & culture
Limited population size & distribution
Bio Anthro midterm 2 pt 2
bio anthro midterm 2