Biology 201Dr. Edwin DeMont

St. Francis Xavier University

Evolution of Man

Linked to Ardi papers.

St. Francis Xavier University

Primates

-Gorillas, chimpanzees, orangutan and humans

Two suborders

(1) Strepsirhini- Lemurs

(2) HaplorhiniSix Families….6. Hominidae

Hominini

St. Francis Xavier University

Evolution of Hominins

5-7 million years ago global temperature dropped.

Tropical forests in Africa broken in mosaic of forests

and vast savannah.

African apes started to graze for food.

Upright posture gave better view of predators and free hands for food gathering and bipedal locomotion evolved.

St. Francis Xavier University

Bipedal locomotion

- Vertebral column curved.

- Vertebrae larger at base.

-Spinous processes reduced.

- Femur angled – puts feet under centre of mass.

Skeletal adaptations for bipedal locomotion

St. Francis Xavier University

Evolution of Hominins

A. Gibbons Science 326, 36-40 (2009)

Published by AAAS

Introductory Video

St. Francis Xavier University

Ardipithecus ramidus

Published by AAAS

4.4 million year old skeleton from Ethiopia

“Facultative” biped

Opposable toe

Flexible hand

St. Francis Xavier University

Evolution of Hominins

Published by AAAS

Video: The Analysis of Ardipithecus ramidus--One of the

Earliest Known Hominids

St. Francis Xavier University

Evolution of Hominins

Published by AAAS

Paleobiological Implications of the Dentition

Humans Ardi Chimp

Honing occurs in canine

Used as a slicing weapon in social conflictsSocial behavioural changes long before tools were used.

St. Francis Xavier University

Evolution of Hominins

Published by AAAS

Paleobiological Implications of the Dentition

Humans Ardi Chimp

Red :Thick EnamelBlue: Thin Enamel

Thick enamel – food abrasive from terrestrial feedingThin enamel – ripe fruits

St. Francis Xavier University

Evolution of Hominins

Published by AAAS

The Pelvis and Femur: The Emergence of Upright Walking

ArdiLucy

Man Chimpanzee

Ilia different shape in chimps – won’t allow repositioning of hips during leg lift-off

Ischial surfaces angled showing hamstrings undergone transformation

St. Francis Xavier University

Evolution of Hominins

A. Gibbons Science 326, 36-40 (2009)

Published by AAAS

St. Francis Xavier University

Evolution of Hominins

There is general acceptance of five Homo species. Fossils of Homo habilis (2.4-1.5 million years ago) demonstrate the presence of Broca's area (an area of the brain devoted to speech).

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St. Francis Xavier University

Evolution of Hominins

Homo erectus (1.8-300,000 years ago) was the first member of the genus to migrate from Africa to Europe, China, and Indonesia. H. erectus used more sophisticated tools and was the first to

utilize fire.

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St. Francis Xavier University

Evolution of Hominins

H. heidlebergeinsis appeared 500,000 years ago.

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St. Francis Xavier University

Evolution of Hominins

H. neanderthalensis (230,000-30,000 years ago). Neanderthal man was specialized for life in the cold climate of Europe and the Middle East. Neanderthals were the first known Homo

species to bury their dead.

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St. Francis Xavier University

Evolution of Hominins

H. sapiens arose in Africa 195,000 years ago. H. sapiens produced fine works of art. Fully modern humans were present about 30,000 years ago.