Macroevolution: Processes of Vertebrate and Mammalian

Evolution

Chapter 5

How old is the human species?

Darwin’s Dangerous idea @8:45

The Earth is 4.6 Billion years old

Australopithicus afarensis 3-1.8mya

Homo habilis 2.1-1.6mya

Homo erectus 1.8-0.3mya

Homo sapien sapiens 92,000ya

Homo sapien sapiens 22,000ya

Million Years Ago

Australopithicus africanus

3.03-2.04 mya

Geological Eraslargest category

• Paleozoic• Vertebrates appeared 500

mya. • Mesozoic • Reptiles were dominant land

vertebrate, placental mammals appeared 70 mya.

• Cenozoic• Divided into Tertiary and

Quaternary periods and 7 epochs.

EPOCHSSMALLEST CATEGORY

• Smallest category of the geological time scale. • In the Cenozoic, epochs include• Holocene• Pleistocene• Pliocene• Miocene• Oligocene• Eocene• Paleocene

Geological Time Scale• The organization of earth history into eras,

periods, and epochs; commonly used by geologists and paleoanthropologists.

Fossils of Mesosaurus, a freshwater reptile living during the Paleozoic Era, have been

found in both Brazil and South Africa

WHY?WHY?

Early Permian period 300mya (in the Paleozoic Epoch)

Permian 225mya

Jurassic 150mya

Cretaceous 65mya

Today

Continental Drift• The movement of continents on sliding plates of

the earth’s surface.• As a result, the positions of large landmasses have

shifted drastically during the earth’s history.

Africa

South America

India

AustraliaAntarctica

FOSSIL EVIDENCE LYSTROSAURUS

GLOSSOPTERISMESOSAURUS

CYNOGNATHUS

PLATE TECTONICS