Lecture 2-2

Lecture 2-2

The Beginnings of Human Culture

Lecture Outline

To what group of animals do humans belong?

When and how did humans evolve? Is the biological concept of race useful

for studying physical variation in humans?

Anthropology: Four Field Discipline Anthropology includes:

– Research on human cultures and languages worldwide and through time.

– Paleoanthropologists analyze ancient fossil humans and their ancestors.

– Primatologists study the behaviors of our closest animal relatives and other primates.

– Others investigate the genetic basis for variations among human populations.

Human Cultural Adaptation Cultural adaptations allow people to

survive in their environment:– Manufacture and utilize tools.– Organize social units to make

searching for food more successful.– Preserve and share traditions and

knowledge.

Human Cultural Adaptation Computer technology enables us to

organize and manipulate information. Space technology may enable us to

propagate our species in extraterrestrial environments.

Biomedical technology may enable us to control genetic inheritance and the future of our biological evolution.

Humans and Other Primates The human species is one kind of

primate, a subgroup of mammals that includes lemurs, monkeys, and apes.

Humans are most closely related to apes:– chimpanzees, gorillas, orangutans,

and gibbons

Anatomical Adaptation Preadaptation

– Characteristics adaptive to one way of life that also are suitable for a different way of life.

Ancestral primates – Preadapted to arboreal life favored by

natural selection. Over time

– Arboreal life involves changes in various anatomical features.

Primate Dentition

Diet available to arboreal primates requires unspecialized teeth.

Over time, there is a trend toward economy, with fewer smaller teeth doing more work:– Number of incisors decrease.– Number of cusps on molars increases.

Sense Organs

Decrease dependency upon sense of smell.

Increase dependency upon sight:– Stereoscopic color vision– Corresponding increase in brain size

in the visual area More acute sense of touch.

The Primate Brain

An increase in brain size, particularly in the areas supporting conscious thought occurred in the course of primate evolution.

In monkeys, apes, and humans the cerebral hemispheres cover the cerebellum, the part of the brain that coordinates muscles and maintains balance.

Rather than relying on reflexes controlled by the cerebellum, primates constantly react to a variety of features in the environment.

The Primate Brain Messages from hands and feet, eyes and ears,

and balance, movement, heat, touch, and pain sensors are simultaneously relayed to the cerebral cortex.

The cortex had to develop in order to receive, analyze, and coordinate these impressions and transmit a response back to the motor nerves.

The enlarged, responsive, cerebral cortex provides the biological basis for flexible behavior patterns found in all primates, including humans.

The Primate Skeleton

Opening of the skull for the spinal cord shifts forward toward the skull’s base accommodating upright posture.

Snout or muzzle portion of the skull reduced

Arms at side rather than the front part of the body

Retention of the primate prehensile hand with opposable thumb

Primate Skeleton

Bison skeleton (left) and Gorilla skeleton (right)

Adaptation Through Behavior Arboreal life involved changes in behavior as

well as in anatomical features. Learned social behavior plays an important

role:– Social behavior rarely observable in fossil

record– Examination of contemporary primate

behavior may lead to clues to early primate behavior and the emergence of human cultural behavior

Chimpanzee Behavior Communities with open subgroups Males generally move Male dominance with mother important in

determining rank Maintain strong mother-child bond Grooming is a common pastime Promiscuous sex when female is fertile Settle disputes by aggressive behavior Dependence upon cultural behavior Make and use tools Males hunt in groups and share kill

Reconciliation and Its Cultural Modification in Primates

There is evidence for reconciliation in more than 25 different primate species.

Reconciliation is common mechanism found whenever relationships need to be maintained despite occasional conflict.

Chimpanzees are the only animals to use mediators in conflict resolution.

Reconciliation is a learned social skill subject to what primatologists now increasingly call “culture”.

Human Ancestors

Chimpanzees and gorillas – Closest living relatives to humans– Humans, bonobos and chimpanzees

98.5% genetically identical Separation from a common stock

– Genetics suggest divergence at least 5.5 million years ago

– Fossil evidence shows separation at least 4.4 mya

Human Ancestors

Ancestors of humans – Most likely apelike animals – Living in Africa– Forced by climactic changes to leave

trees

Monkeys, Apes, and Humans Molecular evidence indicates the split between

the human and African ape lines took place between 8 and 5 million years ago.

The First Hominines: Australopithecus Earliest well-known hominine, who lived

between 1 and 4.2, if not 5.6 m.y.a. and which includes several species.– Found in eastern Africa and westward into

Chad – Fully bipedal – Brain appears apelike – Teeth more like modern humans than apes– Males about twice the size of females– Likely depended upon animal flesh in diet

Homo habilis

Earliest species of the genus Homo Increased consumption of meat

– Living primarily on the savannah– Scavenging from carcasses– Dentition not suited for meat eating,

so they probably needed tools to butcher carcasses.

– Increased brain complexity and size

Homo habilis

Culture– Using wits to compete with large

animals– Food sharing and preparation– Butchering sites where carcasses are

brought

Homo habilis

Invention of tools about 2.5 million years ago– Oldowan tools

•Striking flakes from core– Paleolithic

•The Old Stone Age, characterized by chipped stone tools.

Homo erectus

Species directly ancestral to modern humans Had a body size and proportions similar to

modern humans, though with heavier musculature.

Average brain size fell within the higher range of H. habilis and the lower range of modern human brain size.

Dentition was fully human, though relatively large by modern standards.

Homo erectus

Culture– Fire and cooking circa 700,000 years

ago– Toolkit diversity– New tool making techniques– Selectivity of raw material– Evidence of organized hunting as the

means for procuring meat, animal hides, horn and bone.

Homo sapiens

First appear about 300,000 years ago Archaic Homo sapiens

– Neanderthal• Europe and Asia• Large brained• Massive face

– Other groups found in Java, Zambia, China Modern Homo sapiens

• Less massive face• Less bony architecture

Anatomically Modern Peoples and the Upper Paleolithic Upper Paleolithic peoples

– First people of modern appearance, who lived in the last part of the Old Stone Age.

Culture emerges as a more potent force than biology

Tools surpass the physical equipment of predators

• Bow and arrow

Tool Making: Upper Paleolithic A technique used to manufacture blades: The stone was broken to create a

striking platform, then vertical blades were flaked off to form sharp-edged tools.

Anatomically Modern Peoples and the Upper Paleolithic Art

– Decoration– Sculpture– Pendants– Cave painting

Ritual– Trance– Burial

Race and Human Evolution Anthropologists agree no subspecies

exist within currently surviving Homo sapiens.

As far as contemporary humanity is concerned, race is not a valid biological category.

Anthropologists work to expose the concept of race as scientifically inapplicable to humans.

Race as a Cultural Construct Although biological variation exists in the

human species, biological races or distinct subspecies do not.

Variation such as differences in skin color is the result of genetically adaptive processes to different natural environments.

The majority of human variation exists within populations rather than among populations due to– independent inheritance of individual traits – genetic openness of human populations