ANTH 170 Lab Practical 2

Question 1

Biped

Answer 1

an organism that walks on 2 feet

Question 2

Quadruped

Answer 2

an organism that walks on 4 feet

Question 3

Foramen Magnum

Answer 3

the large opening on the occipital bone where the spinal cord exits the brain

Question 4

Foramen Magnum position

Answer 4

Bipeds - located in a more forward position (anteriorly)
Quadrupeds - located towards the back (posteriorly)

Question 5

Thoracic Kyphosis

Answer 5

an outward curve in the thoracic spine (the portion of the vertebral column that connects with the ribs)
in both quadrupeds and bipeds

Question 6

Lumbar Lordosis

Answer 6

Bipeds - the lumbar portion of the vertebral column is CURVED, positioning the center of gravity posteriorly over the feet; this creates an S-SHAPE in the vertebral column
Quadrupeds - the lumbar portion of the vertebral column is STRAIGHT, positioning the center of gravity anteriorly between the front and back limbs; this creates a C-SHAPE in the vertebral column

Question 7

Pelvis shape and Iliac blade orientation

Answer 7

Bipeds - the ilium is SHORTER and BROADER, with the iliac blades facing more LATERALLY; this provides stability when only one foot is on the ground while walking
Quadrupeds - the ilium is LONGER and NARROWER, with the iliac blades facing POSTERIORLY; this helps to move the thigh straight backward during locomotion

Question 8

Knee Position

Answer 8

Bipeds - the knee is positioned closer to the sagittal plane (midline); this improves balance when walking when only one foot is on the ground (VALGUS KNEE - diagonal)
Quadrupeds - the femoral shaft is oriented more vertically so there is more space between the knees (VARUS KNEE - straight)

Question 9

Intermembral Index

Answer 9

compares the proportions of the upper limbs to the proportions of the lower limbs
length of humerus + length of radius/length of femur + length of tibia

Question 10

Intermembral Index position

Answer 10

Bipeds - have longer hind limbs compared to their forelimbs and overall body size; gives them a longer stride and makes them more energetically effecient
Quadrupeds - have hind and forelimbs that are more equal is size, or the forelimbs are longer in size

Question 11

Arched foot

Answer 11

Bipeds - have a unique “double arch” (one that runs side to side [mediolaterally] and one that runs longitudinally [along the length of the foot]

Question 12

Foot and Toe Length

Answer 12

Bipeds - longer metatarsals and shorter pedal phalanges; longer metatarsals mean increased stride length = more energetically efficient; shortened pedal phalanges in bipeds are because human toes are not being used as grasping organs
Quadrupeds - shorter metatarsals and longer phalanges; longer phalanges can be used as grasping organs

Question 13

Hallux position

Answer 13

Bipeds - the hallux is ADDUCTED (in line) and lack significant grasping capability
Quadrupeds - the hallux can be ABDUCTED (spread away) from the other toes; it is opposable and can be used to grasp objects

Question 14

Sex differences in human pelvic shape

Answer 14

In anatomy, FORM FOLLOWS FUNCTION
Broad pelvis shape of our pelvis allows humans to give birth to live young with large brains
Pelvises that are capable of giving birth (often categorized as ‘female’) are differently adapted to allow safe passage of babies with large brains through the pelvic opening

Question 15

Male vs Female Pelvis

Answer 15

Subpubic angle is narrower in male and broader in females

Question 16

Greater sciatic notch

Answer 16

is narrower in males and broader in females

Question 17

Postorbital constriction

Answer 17

the narrowing of the cranium behind the orbits
related to 2 things - brain size and chewing muscles

Question 18

Larger temporalis

Answer 18

more jaw power while chewing and MORE postorbital constriction

Question 19

Larger brain

Answer 19

more space needed in braincase and LESS postorbital constriction

Question 20

Sagittal crest

Answer 20

mid-line ridge of bone on top of cranium that gives the temporalis muscle extra area for attachment
can form on anterior and/or posterior portion of cranium

Question 21

Larger braincase

Answer 21

has more area for the temporalis muscle = LESS likely to form a sagittal crest than smaller brained forms

Question 22

Anterior sagittal crest

Answer 22

emphasis on molar chewing

Question 23

Posterior sagittal crest

Answer 23

emphasis on incisor biting

Question 24

Dental arcade

Answer 24

2 shapes of dental arcades (dental arch): u-shaped or parabolic

Question 25

U-shaped dental arcade

Answer 25

canines form corners, premolars and molars arranged in relatively PARALLEL rows

Question 26

Parabolic dental arcade

Answer 26

ROUNDED arc shape (sometimes called V-shape) molars and premolars NOT in parallel rows between left and right side of mouth

Question 27

Molarized premolars

Answer 27

a unique dental feature found ONLY among members of the genus PARANTHROPUS
these premolars resemble molars (larger, flatter, and broader) than a normally shaped premolar

Question 28

Femoral condyle evenness

Answer 28

Medial femoral condyle is on the medial side of the femur (same side as the femoral head - toward body’s midline)
Lateral femoral condyle is on the lateral side of the femur (toward the outside of the body)
In bipeds, the medial femoral condyle is larger and extends further than the lateral femoral condyle (this unevenness keeps the tibia vertical and maintains knee alignment)

Question 29

Genus Homo: Key Features

Answer 29

As hominins evolve, they have:
Larger bodies and larger brains
Less prognathism
Smaller teeth
Reliance on increasingly sophisticated tools for survival

Question 30

Homo habilis

Answer 30

First appeared in Africa ~2.4 to 2.1 Ma where it lived alongside Homo erectus and Paranthropus
Persists until about 1.4 Ma
First known hominin species to use tools (Oldowan tool industry); these tools were relatively crude

Question 31

Homo erectus

Answer 31

First appeared in Africa ~2 Ma where it lived alongside Homo habilis and Paranthropus
First hominin species known outside of Africa
Persisted until about 100,000 years ago in isolated parts of Asia
Used large Acheulean cutting tools, occupied non-tropical environments, and possible had the first controlled use of fire

Question 32

Homo heidelbergensis

Answer 32

Replaces Homo erectus ~800 ka in Africa and Europe
Persists until ~300-200 ka
Known from Africa, Europe, and possibly Asia
Have some key features shared with H. erectus and others with younger species (modern humans or Neanderthals)
In Africa appears to evolve into H. sapiens
In Europe appears to evolve into H. neanderthalensis

Question 33

Homo sapiens (anatomically modern humans)

Answer 33

First appear in Africa ~300 ka
First appears outside of Africa ~210 ka; in southern Greece, but this early dispersal may not have been permanent
First appears in the Levant ~180 ka, southern China ~120-80 ka, elsewhere in Asia by ~50 ka, Australia ~50 ka, Europe (possibly more permanently) ~45 ka, the Americas between 20-15 ka

Question 34

Sagittal keel

Answer 34

Smooth, raised area of bone located along the top of the cranial vault along the MIDLINE of the skull
Potentially functions as a way to protect the brain from shocks when hit
NOT a site for muscle attatchment
Present in some species of genus Homo
When present, can be more or less projecting

Question 35

Supraorbital Torus

Answer 35

Smooth, raised area of bone right above the orbits (BROW RIDGE)
Located on the frontal bone
Can be more or less projecting

Question 36

Supraorbital Sulcus

Answer 36

A DEEP GROVE right behind the supraorbital torus
Located on the frontal bone
Present in some species of genus Homo
Can be deep or shallow when present

Question 37

Occipital Torus

Answer 37

Smooth, raised area of bone on the occipital bone
Can be more or less projecting

Question 38

Area of max cranial breadth

Answer 38

The area in the back of the skull where the skull is widest

Question 39

Retromolar gap

Answer 39

A triangular gap behind the 3rd molar in the back of the mouth
Characteristic feature of members of the species Homo neaderthalensis

Question 40

Mental eminence

Answer 40

A bony chin that extends past the teeth
Characteristic feature of members of the species Homo sapiens

Question 41

Oldowan Tools

Answer 41

Earliest stone tools
First appear ~2.6 Ma and persist for over 1 million years
Relatively simple tool where a flake is removed from a core of fine-grained rock to produce a sharp cutting edge
Flake is the likely tool, not the core
Associated with H. habilis

Question 42

Acheulean Tools``

Answer 42

First appear ~1.8 Ma and persist until ~250 ka
Core flaked bifacially to produce relatively symmetrical “handaxe”
The core is likely the tool, not the flake
Associated with H. erectus