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EVOLUTION
Ch. 23
Evolution
Evolution Outline• Formation of the earth & chemical evolution
• Early beginnings of cells
• Critical events leading to evolution Evidence • 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
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
•Dr. Stanley Miller (1930-2007)
Miller’s Experiment showed:
• Organic molecules can be formed from components of Earth’s early atmosphere.
Collections of polymers.heterotrophs
autotrophs
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
Insects 40 million years ago trapped in amber
SUMMARY
Ocean
First species to invade the land came from the oceans were likely plants. Soon after the plants invaded, animals came ashore.
First animals were probably scropion-like.
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(or beginning !)
An artist’s interpretation of how “Lucy” may have looked.