Chapter 5
Macroevolution: Processes of
Vertebrate and Mammalian Evolution
How old is the human species?
Darwin’s
Dangerous idea @8:45
The Earth is 4.6 Billion years old
Homo
Homo
Australopith Homo
erectus 1.8-sapien
sapiens
icus
habilis 2.1-0.3mya
92,000ya
afarensis 3- 1.6mya
1.8mya
Homo
sapien
sapiens
22,000ya
Australopithicus
africanus
3.03-2.04 mya
Million Years
Ago
Geological Eras
largest 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.
EPOCHS
SMALLEST 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?
Early Permian period 300mya (in
the Paleozoic Epoch)
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.
Today
Cretaceous 65mya
Jurassic 150mya
Permian 225mya
FOSSIL EVIDENCE
Africa
LYSTROSAURUS
India
South America
Australia
Antarctica
CYNOGNATHUS
MESOSAURUS
GLOSSOPTERIS
PLATE TECTONICS