Final - Lab Manual Flashcards
The 7 anatomical traits indicating bipedality in hominins:
Foramen magnum position, vertebral column shape, pelvic shape, limb proportions, femoral angle, foot morphology, hallux position
Bipedalism evolved in a ____ fashioin
Mosaic
Quadrupeds/Bipeds foramen magnum position:
Foramen magnum is large opening in occipital bone through which spinal cord passes
Quadrupeds: Located posteriorly at back of skull
Bipeds: Located anteriorly underneath the skull
Quadrupeds/Bipeds vertebral column shape:
Quadrupeds: Center of gravity low, remains between four limbs; C-shaped spines
Bipeds: Center of gravity towards midline of body, spinal curvature altered; S-shaped spines
Quadrupeds/Bipeds pelvic shape:
Quadrupeds: Pelvis tall and narrow
Bipeds: Wide and basin-shaped
Quadrupeds/Bipeds limb proportions:
Quadrupeds: Oppositive of biped description
Bipeds: Long lengs relative to their trunk and arms, shorter upper limbs
Quadrupeds/Bipeds femoral angle:
Femoral angle is angle between distal femur and proximal tibia at the knee
Quadrupeds: Shorter femoral neck; ~90 degrees varus knee
Bipeds: Longer femoral neck; proximal femur laterally placed;
Quadrupeds/Bipeds foot morphology:
Quadrupeds: Move on all four limbs, hand and feet have similar function
Bipeds: Move on two legs, hands and feet have different functions-evolution of transverse (running medially to laterally along plantar surface of foot) and longitudinal arches (running length of foot)
Quadrupeds/Bipeds hallux position:
Hallux is the big toe
Quadrupeds: Divergent
Bipeds: Enlarged, use as an opposable digit lost (adducted and not divergent)
Fossil evidence of bipedalism first appeared in hominin lineage about ____ million years ago
7
What limb proportions would you expect to see on a hominin?
Long legs relative to arms
Humans have a ____ knee
Valgus
Potential problems for classifying paleospecies:
Allometry, Sexual dimorphism, Incomplete fossil record, Intra-specific and inter-specific variation
Name the five genuses within the subfamily homininae and tribe hominini:
Sahelanthropus, orrorin, ardipithecus, australopithecus, homo
Name the 7 traits used to distinguish hominins from other apes:
Bipedalism, increased encephalization, reduced prognathism, reduced diastema, lack CP3 honing complex parabolic dnetal arch shape, thick dental enamel
Encephalization apes/humans:
Chimpanzees: 350-400cc
Modern humans: 1300-1400cc
Chewing habits apes/humans:
Apes: Chew and slice their food, using muscles of mastication
Humans: Crush and grind their food
Dental arch shape apes/humans:
Apes: U-shaped (parallel rows of cheek teeth)
Humans: Parabolic (diverging cheek teeth)