EVOLUTION

Evolution

(material for extra credit questions)

Outline

• Approximate date of earth formation

• Theory of Chemical Evolution & evidence for chemical evolution– Miller’s Experiment

• Timeline for emergence of first Cells

• Evidence supporting evolution

• Early Primate evolution – Evolution of the Genus Australopithecines

– Evolution of the Genus Homo & modern humans

4.5 billion years ago the earth formed

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Earth formed

Chemical Evolution began

First Eukaryotes emerged

First Prokaryotes emerged

4.5 billion years ago

4 billion years ago

3.5 billion years ago

1.2 billion years ago

Miller’s Experiment showed:

• Organic molecules can be formed from components of Earth’s early atmosphere.

Collections of polymers.heterotrophs

autotrophs

Ocean

First species to come to land from our oceans were plants.

PLANT LIFE

• Plants provided O2

• Provided ozone layer• Protection against UV

Evolutionary changes

• Anatomical• Functional• Behavioral

How do these changes occur?

Charles Darwin: 1809-1882

1831-1836

1859

DARWIN’s TRAVELS

2 conflicting theories

Key components of evolutionary process

• Genetic variation

• Natural selection

• Survival of the Fittest

Evidence supporting natural selection

1. Fossil records

2. Homologous structures

3. Biochemical similarities

– DNA– Amino acids

98% similar

Humans

Chimpanzees

(DNA of fossils is also being studied)

4. Embryologic development

Sea urchin

Cockatiel

Mouse

Human

• 5. Biogeography

Super continent 240 million years ago

• 6. Experimental Evidence

Primate Evolution

Earliest primates included theTarsiers

Primates (order)

Prosimians Anthropoids

Old world monkeys hominoidsNew world monkeys

Great Apes

Lesser Apes

Hominids

Genus:Australopithecus

Genus: Homo

Consist of

Ruff lemur tarsier

Consist of:

Mandrill Spider Monkey

Australopithecus afarensis

Approx. 3.2 mya

“Lucy”

Approx. 25-30 years old

Approx. 60 pounds

Approx. 3 ft tall

Discovered byDr. Donald Johanson mid 70’s

Australopithecus afarensis

• Bipedal• Approximately 3 to 5.6 ft in height

• Over 1 million years ago Australopithecus disappeared.

Homo habilis“skillful man”

• Lived 1.8 million years ago

• Discovered 1960 in Tanzania by Dr. Mary Leakey

Brain is 50% larger than Australopithecus

Homo erectus“upright man”

• Lived 1.6 million years ago

• H. erectus moved from Africa to Europe and Asia

Used fire

maleApproximately 12 years oldLived approximately 1.6 million years ago

Homo erectus(stood approximately 5 ft tall)

Turkana BoyFound in 1984 in Kenya

Homo sapien“thinking man”

• Emerged approx. 300,000 years ago

• 2 subspecies– neaderthalensis– sapien

Skull of Homo sapien neanderthalensis

Lived in small clans and had elaborate burial rituals.

Homo sapien sapien

• Neaderthanls disappeared about 40,000 years ago

• About 300,000 years ago enter Homo sapien sapien

Skull of early Homo sapien sapien

Cro-Magnon Man

Homo sapien sapienCro-Magnon Man

Artistic with perhaps a well developed language

Excellent hunters

Lived in communities

Homo sapien sapien“modern man”

• Appeared approximately 10,000 years ago

• Very little change over the past 40,000 years

The End!