Chapter 10

Question 1

What are the major trends in hominid evolution?

Answer 1

Bipedalism
Expansion of the Brain
Reduction of Face, Teeth and Jaws
Other Evolved Traits: Neoteny, Loss of body hair, Fine motor control

Question 2

What are the theories for bipedalism?

Answer 2

Habitual upright locomotion.
Theories:
Adaptation to life in savannahs
Better dispersion of body heat
Freeing of hands to carry food or make tools

Question 3

Describe Darwin’s hunting hypothesis

Answer 3

That Hominins evolved in Africa

Hunting meat = tool use = large brain + small canine•Tool use = free hands = bipedalism

Question 4

Describe the patchy forest hypothesis

Answer 4

Peter Rodman andHenry McHenry
African savanna
bipedalism arose because it was more energy-efficient in certain environments, especially those with few trees

Question 5

Describe the bipedal skeleton

Answer 5

Foramen magnum centered at the base of the skull
Changes to the pelvis becoming more bowl shaped
Legs angle inward at the knee
Enlarged ankle bones and arch in the foot

Question 6

Describe the provisioning hypothesis

Answer 6

Owen Lovejoy
More food supports more infants, lower interbirth interval (IBI)
Suite of anatomies and behaviors coevolve
Food provisioning
Pair-bonding
Reduced canine size
Cooperation
Bipedalism

Question 7

What is different about humans?

Answer 7

Upright walking
Nonhoning chewing
Material culture + Speech
Hunting and cooperation
Domestication of plants and animal

Question 8

Describe Non-Honing chewing

Answer 8

Honing vs. apical wear
Shearing vs. grinding
Male–male aggression
Smaller teeth = less comp. + more group stuff

Question 9

What is the effect of tooth enamel and masticatory muscles on evolution?

Answer 9

Humans have thicker enamel than chimps
Chimps = sharp teeth, slicing even w/ little enamel. Ripping.
Human = grinding + crushing, processing + chewing
Thin enamel = tooth decay = starvation = death
Better chewing = more nutrients
Size + where muscles attach (smaller masticatory muscles = brains get bigger)

Question 10

Describe the East African Rift Valley sites

Answer 10

Good dates, good preservation of fossils, good diversity
Past: African savannah landscapes, Now:
Olduvai Gorge - Lewis and Mary Leakey
Olorgesaillie, Tanzania Mary Leakey, Henry Bunn and Ellen Kroll

Question 11

Describe the South African sites

Answer 11

Vertical shaft caves - lotsa fossils, but all mixed, hard to date
Swartkrans, Sterkfontein
Taung child - Raymond Dart - 1st hominin fossil found in Africa (1920)

Question 12

Late Miocene-Pliocene Proto-hominids

Answer 12

Sahelanthropus tchadensis 7mya (Position of the foramen magnum indicates a more upright posture=bipedalism?)
Orrorin tugenensis 6.1 - 5.7 mya (Small, human-like teeth Femur = bipedalism)
Ardipithecus ramidus (foot bones divergent large toe combined with rigid foot –• unclear concerning bipedal behavior. pelvis = adaptations tree-climbing + bipedal activity

Question 13

Describe the issue of the multiple species of pliocene-pleistocene australopithecenes

Answer 13

Things usually consolidate, we think they’re separate but maybe same, but we also could have had that many.
Very many hominins using tools, interbreeding + eating varied diets.

Question 14

Describe Australopithecus anamensis

Answer 14

Kenya and Ethiopia, Africa ~4 million years old
Woodland
M. Leakey and T. White
Anatomies: Bipedal = Based on shin bone, Nonhoning canines - pretty good adaptation to dispensary tree climbing

Question 15

Describe Australopithecus afarensis

Answer 15

Fossils from east Africa (Hadar + Laetoli) 4-3 mya
‘Lucy’ – a juvenile called her baby was also found. Donald Johanson. 40 % complete, from about 3.2 mya - Good jaw, complete femur + rotating pelvis
Angled knee (valgus) = easy to walk + give birth
Bipedal (some climbing?); Nonhoning, small canine, Large molars, No language

Question 16

Describe the Taung child and its discovery

Answer 16

1920 in South African quarry site, Raymond Dart
1925 = 5-7 yr old child (new studies indicate probably was 3-4 yrs old)
named Australopithecus africanus – “Southern ape of Africa”

Question 17

Describe Australopithecus Africanus

Answer 17

3-2 mya Cranial capacity  ~450 cc (1/2 L)
Large, chinless jaws
Broad, bowl shaped pelvis, Walked erect
S-shaped spinal column
Southern Africa ~ 3 + 2 mya

Question 18

Describe the robust Australopithecenes

Answer 18

Au. robustus: South Africa, 1.8 - 1 mya (Dart)
1.5–2 mya. Small, nonhoning canines; very large premolars + molars
Au. boisei: East Africa 2.2 to 1.3 mya. (M. Leaky)
Thicker jaws, larger molars and premolars. Massive muscle attachments for chewing. Larger cranial capacity ~490-530 cc
Both bipedal

Question 19

Describe Australopithecus Sediba

Answer 19

2 million years old (Malapa cave), South Africa
Forest and grassland, Eating C3 foods
Anatomy: Small brain, small teeth. 
Human-like hand and pelvis, Mosaic foot
Lee Berger

Question 20

Describe Au. Aethiopicus

Answer 20

East Africa
Small brain, big cranial crest
Small teeth, lots of masticatory muscles
Face in front of brain

Question 21

Describe early hominid tool culture

Answer 21

Earliest identifiable tools East Africa ~2.5 mya
Yes soft tissue stuff too, but it decomposed!
Homo habilis associated w/ Oldowan tool tradition
Hominid tool culture Raymond Dart, proposed a culture for Australopithecines : Osteodontokeratic (Bone-tooth-horn)

Question 22

Describe Oldowan tool making

Answer 22

smashing two rocks against each other where pieces are picked off to make tools
1 harder rock and 1 softer

Question 23

Describe Lomekwi stone tool making

Answer 23

3 mya
Australopithecus or Kenyanthropus
Simple - smashing one stone against another on the ground