Terms to Know

1.Biogeography

2.homologous structures

3.analogous structures

4.Vestigial structures

Evidence of Evolution

Isabela Island

Hood Island

Biogeography is the

study of where organisms

live now and where they and

their ancestors lived in the

past.

Rhea: South Amer. Ostrich: Africa

Emu: Australia

• How Old is the Earth???

• https://youtu.be/5yFnO2O6XPM

• Evolution takes a long time. If life has evolved, then

Earth must be very old.

• Radioactive dating indicates that Earth is about 4.5

billion years old —plenty of time for evolution by

natural selection to take place.

• Homologous structures - shared structures that have

been inherited from a common ancestor.

Same common ancestor!

• Analogous structures - Body parts that share a

common function, but not structure.

Different Ancestors!

• Vestigial structures are inherited from

ancestors, but have lost much or all of their original

function.