Lecture 2-1
The Beginnings of Human
Lecture Outline
When, Where, and How Did the Genus
Homo Develop?
 When Did Reorganization and
Expansion of the Human Brain Begin?
 Why Is the Relationship Between
Biological Change and Cultural Change
in Early Homo?
Development of Human
Some populations of early hominines
began making stone tools to butcher
animals for their meat.
 The earliest stone tools and evidence of
significant meat eating date to about
2.6 m.y.a.
Reorganization And
Expansion Of The Human
Began at least 1.5 million years after
the development of bipedal locomotion.
 Began in conjunction with scavenging
and the making of stone tools.
 Marks the appearance of the genus
Homo, an evolutionary offshoot of
Reorganization And
Expansion Of The Human
Australopithecus relied on a vegetarian
diet while developing a massive
chewing apparatus.
 Homo ate more meat and became
Early Representatives of
the Genus Homo
Since 1960 a number of fossils have been
found in East Africa, and in South Africa,
which have been attributed to Homo habilis.
From the neck down, the skeleton of Homo
habilis differs little from Australopithecus.
Skull shows a significant increase in brain size
and some reorganization of its structure.
Hand bones
Comparison of Partial
Foot Skelton
Homo habilis (center) compared with a
chimpanzee (left) and modern human (right).
Homo habilis and Other
Early Hominins
Tool Use
Lower Paleolithic artifacts from Olduvai Gorge,
Lake Turkana, and sites in Ethiopia required
skill and knowledge for their manufacture.
The oldest Lower Paleolithic tools found at
Olduvai are in the Oldowan tool tradition.
Oldowan choppers and flakes made the
regular addition of meat to the diet possible.
Brain Structure and Tool Use
Tool making favored the development of
a more complex brain:
–Requires a vision of the tool to
be made.
–Ability to recognize the kind of
stone that can be worked.
–Requires steps to transform the
raw material into a useful tool.
Sex, Gender and the
Behavior of Early Homo
Males supplied much of the meat, while
females gathered other foods.
 Females shared a portion of what they
gathered in exchange for meat.
 Sharing required planning and problem
Tools, Food, and Brain
Increased consumption of meat, beginning
about 2.5 m.y.a. made new demands on
coordination and behavior.
Procuring meat depended on the ability to
outthink more predators and scavengers.
Eaters of high-protein foods do not have to eat
as often as vegetarians, leaving time to
explore and experiment with their
Language Origins
There is a growing consensus that all
great apes share an ability to develop
language skills to the level of a 2- to 3year-old human.
 In the wild apes display language skills
through gestures.
Language Origins
Regions of the human brain that control
language lie adjacent to regions
involved in precise hand control.
 Oldowan toolmakers, like modern
humans, were overwhelmingly righthanded.
 In making tools, they gripped the core
in the left hand, striking flakes off with
the right.
Language Origins
Handedness is associated with
lateralization of brain functions and
lateralization is associated with
 Tool making appears to have been
associated with changes in the brain
necessary for language development.
Brain Lateralization
Lateralization is the idea that the two halves of
the brain's cerebral cortex -- left and right -execute different functions. The lateralization
theory -- developed by Nobel-prize-winners
Roger Sperry and Robert Ornstein -- helps us
to understand our behavior, our personality,
our creativity, and our ability to use the proper
mode of thinking when performing particular
tasks. (The cerebral cortex is a part of the
brain that exists only in humans and higher
mammals, to manage our sophisticated
Is your Brain CrossLateralized?
The human brain has two hemispheres,
each differing from the other. This is
called hemispheric lateralization.
Basically, people are either right- or lefthanded. When it comes to other traits, in
addition to handedness, people are rightor left-dominant. How is your own brain
generally lateralized? Do you have any
cross-lateralizations? Take this brief quiz
to discover your degree of crosslateralization, and what it may mean.
1. Are you primarily left- or righthanded?
left right
 2. When kicking a football, which
foot do you use to kick it?
left right
 3. Cross your arms comfortably.
Which hand is on top?
left right
4. Keep both your eyes open while
you extend your hand and point to
an object twenty feet away. Now
close your left eye. Is your finger
still pointing directly to the object,
or did a shift occur?
- it's still pointing directly to
- no, a shift occurred
5. Clasp your hands comfortably. Is your
right thumb on top?
yes no
6. When writing in longhand, which hand
do you use to hold the pen?
left right
7. When tossing a ball, which hand do
you use?
left right
8. When chewing gum, which side
do you usually chew on?
left right
9. When talking on the phone,
which ear do you put against the
left right
For results go to:

L-2-1-Beginnings of Human Culture