How Did We Become Human?

HumanitiesUnit 1: Origins

What Does Mythology Say?

• Most basic of all questions: our origins– Where do humans come from?– How was the earth created? The stars? The sun?

The moon?– How should we live our lives?

Functions of Myth• Provide Moral lessons

– “Myth fulfills in primitive culture an indispensable function: it expresses, enhances, and codifies belief, it safeguards and enforces morality, it vouches for the efficiency of ritual and contains practical rules for the guidance of man.” (Bronislaw Malinowski)

– Serve as guides, or charters, for moral values, social order and magical belief. – “Myth is thus a vital ingredient of human civilization; it is not an idle tale, but a

hard-worked active force; it is not an intellectual explanation or an artistic imagery, but a pragmatic charter of primitive faith and moral wisdom.” (ibid.)

• Assure, encourage, inspire• Usually some element of science: explanation, but no

verification—only acceptance– Key element is CAUSATION– Science= impersonal– Myth= personal– Who do humans know best? Themselves.

• Project human thoughts and emotions on external world

Kinds of Myths• Kinds of myths:

– World was created first– World has always existed

• Some Similarities:– People created in a series of creative acts– Usually the work of supernatural beings or forces– Duality of creational entities

• i.e. flood myth– Explain varieties of animal life– Close association between animals and men– Humans used to belong to one tribe but something happened to

divide them– Tell of a golden age/age of innocence ruined by act of man

• i.e. Creation/Use of fire

• Differences?

What Does Science Say About Creation?

• The Pre-Socratics• The Big Bang

– Do you see any connections between creation stories and the Big Bang?• Evolution and Natural Selection

– How Does It Work?• The Controversy Over Evolution

– How do We Balance Faith and Reason?• Human Evolution

– As we evolve we become more complex and thus more fragile—our bodies and our institutions

• Human social and cultural evolution• What is the future of the human race?

– Are we still evolving?– Are we doomed?

The Pre-Socratics:Started turning to science and observation to explain the origins of the earth and universe

Thales (624-546 B.C.):

• Father of Philosophy• Primarily interested in

material world• Predicted first solar eclipse• Thought water was root of

the world (1st principle.)

Anaximander ca. 610 – ca. 546 BCE

• First metaphysician; learned from Thales

• Water is too definite• Nature is ruled by laws• “The Boundless” or “the

unlimited” (apeiron) is the origin of everything

• Life first rose out of the moisture from the seas as they dried up

• Everything definite returns to the indefinite

Pythagorasca. 610 – ca. 546 BCE

• All things, including political and social institutions are numbers

• Contrast of odd and even numbers shows harmony in the universe

Heraclitusc. 535 – c. 475 BCE• Famous for his insistence

on ever-present change in the universe

• “No man every steps in the same river twice”

• No entity may ever occupy a single state at a single time

• Considered fire as the most fundamental element.

• Believed fire gave rise to the other elements and thus to all things.

Parmenides 540-470 BCE

• Father of Metaphysics

• Two views of reality. • “The way of truth": reality is one,

change is impossible, and existence is timeless, uniform, necessary, and unchanging.

• "the way of opinion”: explains the world of appearances, in which one's sensory faculties lead to conceptions which are false and deceitful.

• Strongly influenced the whole of Western philosophy, especially Plato

• Heraclitus and Paremenides: 3- Minute Philosophy

The “Big Bang”

• Stephen Hawking's The Big Bang

• What Caused the Big Bang?

Charles Darwin• Natural Selection: Top 1

00 Discoveries• Evolution and Natural S

election

Evolution and Natural Selection

• Evolution 101• Natural selection is simply the logical result of four

features of living systems:• variation - individuals in a population vary from one

another• inheritance - parents pass on their traits to their

offspring genetically• selection - some variants reproduce more than others• time - successful variations accumulate over many

generations

Short Videos on Evolution

• #1 Isn't Evolution Just a Theory?• #2 Who was Charles Darwin?• #3 How Do We Know Evolution Happens?• #4 How Does Evolution Really Work?• #5 Did Humans Evolve?• #6 Why Does Evolution Matter Now?• #7 Why is Evolution Controversial Anyway?

How Do We Balance Faith and Reason?

• What does Genesis tell us about the origins of the earth? What did Darwin tell us? Can we believe both?

• Creationism: The belief in a god who is the absolute creator of heaven and earth, out of nothing, by an act of free will. – The Bible is a literally true guide to the history of the universe– “Young Earth Creationists”: The world is 6,000 years old; all creation

happened in 6 days• Intelligent Design: certain features of the universe and of living

things are best explained by an intelligent cause, not an undirected process such as natural selection.

• NOVA: Inteligent Design on Trial• Did Darwin Kill God?

Human Evolution

• Humans are not immune from the process of natural selection

• We share a COMMON ANCESTOR with primates

• We are not DESCENDED FROM THEM

Two main groups of primates:

Prosimians: lemurs, lorises, pottos & tarsiersAnthropoids: monkeys, apes and humans

Early Primates

• Prosimians (~58mya)• Monkeys (35mya)• Apes (23mya)• Hominids (~6mya)

TarsiersLemurs

LorisPottos

Prosimians

ANTHROPOIDS:Monkeys, Apes and Humans

New World Monkey:Flat face

Wide nostrils

Prehensile tail

Old World Monkey:Long snout

Close nostrils

Non-prehensile tail

Selective Environmental Pressures

East Africa Rift Valley

What Characteristics Do We Share With Primates?

• Earliest primates lived in trees• Major selective pressures:– Most primates have flat nails as well as sensitive

pads on the undersides of fingers and toes.– Many also have both an opposable big toe and

thumb.– Mobile limbs and clawless opposable digits allow

primates to freely grasp and release tree limbs.

Primate Hands

Topic 14 – Human Evolution

Binocular Color Vision

Skull Comparisons:

Other Characteristics

• Upright posture• Excellent hearing • Small litter size (usually one baby)• Expanded forebrain, larger brain capacity• Long lifespan• Social networks: work together as a group

Advantages?

What We Share With Chimpanzees• 2 species, tropical Africa• Sister group to humans.• Share 97% of DNA w/ chimps.• Many morphological features shared. • Make and use simple tools• Have sense of self.• Omnivorous. • Cuddle babies, breast feeding. • Ability to walk bipedally• Bonobos often have frontal sexual intercourse.• Bonobos vs. Chimps• https://www.ted.com/talks/susan_savage_rumbaugh_on_ap

es_that_write

To Be Human

A. afarensis

A. africanus

A. boisei

A. robustus

Early Discoveries

Australopithecus Afarensis

• “Lucy”• Discovered 1974 in

Afar region of Ethiopia

• Estimated to have lived 3.2 million years ago

• Bipedal• No known tool use• Finding Lucy• New Species of Hum

an Discovered in South Africa Paleoartist John Gurche

(Courtesy of Smithsonian)

Genus “Homo”• Homo habilis “Handy Man”

– Found in East Africa– primitive stone tools– 2.4 – 1.4 million years ago

• Homo erectus “Upright Human Being”– 1.9 million – 143,000 years ago– More advanced tools– First to migrate out of Africa– First to use fire– Most famous called “Turkana Boy”– Direct ancestor of Homo sapiens?

Genus Homo

• Homo sapiens neanderthalensis– Closest extinct human

relative– Sophisticated tools– Wore clothing– Lived in shelters– Buried their dead– Used symbolic imagery– DNA has been

extracted from more than a dozen specimens all over Europe

– Low, receding forehead– Brow ridges

Homo sapiens sapiens• Modern humans• First evolved in

Africa 200,000 years ago during period of dramatic climate change

• Big brain• High forehead• No brow ridges• Smaller jaws and

teeth