Human Evolution

TOC# 21

QQ#1: From

what/ where d id

humans evolve?

http://hum

anorigins.

si.edu/reso

urces/intro

-human-

evolution

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down all

the way

for video

WE DID NOT EVOLVE FROM

MONKEYS OR APES

Where did humans come from?

Human Evolution

I. How Do We Study Human Evolution?

A. Paleontologists study fossil primates and compare them with

living forms

B. Archaeologists and anthropologists study ancient tools and

cultures

C. Molecular Biologists examine DNA of d ifferent species looking

for similarities and d ifferences

II. Where and When Did Humans Evolve?

A. Homo sapiens evolved from a common ancestor that we share with

other living primates (chimpanzees, apes etc.)

B. Homo sapiens evolved in Africa and spread around the world

C. Homo sapiens first appeared 500,000 years ago

• The “ day before yesterday” on an evolutionary time scale

• Over 60 million years after the d inosaurs went extinct

The spread of humans over time

II. Where

and When

Did Humans

Evolve?

Human

Chimpanzee

Gorilla

Orangutan

III. Lets look at the chromosomes

IV. Characteristics of The Human Order - Primates

A. As a group, primates share several important adaptations:

1. Flat faces, reduced snout

2. Eyes d irected forward; binocular vision for depth perception;

see in color

3. Flexible fingers for grasping

4. Full shoulder rotation

5. Nails (vs. claws)

6. Complex, large cerebrum

7. Extended maternal care for young; usually 1 offspring at a time;

2 mammary glands

8. Complex social groups and behavior

http://humanorigins.si.edu/resources/intro-human-evolution

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V. Members of the Primate Group

A. Prosimians

1. Lemurs, lorises and aye-ayes

• Nocturnal and have large eyes well

adapted to seeing in the dark

IV. Members of the Primate Order

B. Anthropoids (human-like primates)

1. New World Monkeys

A. Monkeys in Central and

South America

• All are arboreal with

grasping tails

2. Old World Monkeys

A. Baboons and macaques

• Do not have grasping

tails, some are arboreal

C. Great Apes (Hominoids)

1. Gorillas, gibbons, orangutans,

chimps and humans

VI. Hominid Evolution

A. Between 4 and 9 million years ago, the hominoid line in Africa gave rise

to a small group of species called Hominids.

B. Hominid Characteristics (that d istinguish them from other hominoids):

1. Omnivorous

2. Bipedal locomotion

3. Opposable thumb

4. Remarkable increase in

brain size (cerebrum)

• Compare chimp brain

size (280-450 cm3)to human brain size (1200-1600 cm3)

VI. Hominid Evolution

C. General Trends in Hominid Evolution Over Time

1. Increase in brain size and body mass

2. Reduction in area of lower face; jaw angle; size of brow ridge

3. Increase in wid th of pelvic opening (why?)

4. Presence of Broca’ s Area (ind icates possibility of speech)

VII. Our Hominin Ancestors

A. Genus: Australopithecus (“ Southern Ape”)

1. First known hominin

2. Walked upright

3. Four species existed :

• A. boisei

• A. robustus

• A. afarensis

• A. africanus

4. Lived between 4.4 and 1.1 million years ago

VII. Our Hominin Ancestors

B. Genus: Homo

1. Homo habilis (“ Handy Man” )

• Smaller face, larger brain than Australopithecus

• Used primitive tools made of stone and bone

• Lived between 1 and 2 million years ago

VII. Our Hominin

Ancestors B. Genus: Homo

2. Homo erectus

• Larger brain than Homo habilis (cranial capacity > 800 cm3)

• By 1 million years ago, they had spread from Africa to

Europe and Asia

• Excellent tool maker (crafted and used hand axes)

• Used fire for cooking

• Lived in primitive huts

• Used speech to communicate

VII. Our Hominin

Ancestors B. Genus: Homo

3. Homo sapiens neanderthalensis

• First d iscovered in the Neander Valley in Germany

• Lived between 150,000 and 30,000 years ago

• Constructed burial sites for the dead

• Wore jewelry and clothing

• Very similar to modern humans

VIII. Modern Humans

A. Genus: Homo

1. Homo sapien sapiens

• The first hominins tru ly identical to modern humans

appeared in Africa, roughly 100,000 years ago and were

called Cro-Magnon

• Complex culture; talented artists

• Wide variety of stone and bone tools: spear points, knives,

chisels and needles

• Lived side by side the Neanderthals in several locations

around the globe

• When Neanderthals d isappeared , only Homo sapiens sapiens

remained to populate the rest of the world